Everyday Scientist

Lickey Quartizite – Bilberry Hill Quarry 1976-1987

2010-08-01T13:44:00.002-05:00

The Bilberry Hill or Overfold Quarry in the Lickey Quartzite is situated 600 m N.N.W. of Kendal End, near Birmingham. It is currently (July 2010) being cleared of vegetation and enlarged as an exhibition site by Worcestershire Earth Heritage Trust, in a project managed by Evelyn Miles. Work done for B.G.S. by S.G. Molyneux, twenty years ago, yielded organic-walled microfossils of early Ordovician age. This suggests that the best correlation would be to the Arenig Stiperstones Quartzite with Scolithos Haldeman vertical burrows, rather than to the basal Cambrian Tuttle Hill Member of the Hartshill Formation with paired U-shaped Burrows termed Arenicolites Salter. Both types of trace fossil have no age significance above the Precambrian. Arenicolites is the trace fossil name for the lug worm burrows still made in the mud on Southend Beach by Arenicola. It would, however, be instructive to determine whether the burrows now potentially becoming available on large sandstone slabs in the quarry consist of pairs of shafts termed Arenicolites, or the single if often numerous ones termed Scolithus. In Arenicolites the seawater is passed through the burrow, often preserved as a pair of funnel-like entrances, represented by domes on the sandstone base above it. The west side of the quarry shows a continuous succession of bands of sandstone and thin shales in the lower limb of the fold. Measured sections look different due to the absence of distinctive beds The south-east corner of the quarry showed green, glauconitic shales, laminated with 0.4 mm muscovite and clearly separated from similar shales at the base of the continuous section by a fault. It trends nearly parallel to the overfold on the west side of it. The fold axis plunges at 20° slightly W. of true north, judging from measured bedding planes around it. They include an intertidal channel cutting out about 0.1 m of sandstone at the fold axis. Measurements made here in July 9, 1978 with respect to Magnetic North (presumably 7° W of true N.) showed a dip of 21° S on a strike of 134° E. of Magnetic N. on the channel margin paleoslope, compared to 5° Mag. N. on a strike of 49°on the level bedding plane above the channel.

The talus cone yielding the fossil burrows was on the opposite N.W. side in the lower limb of the fold. This face showed 3 mm thick bands of arkose granules in sandstone at the base (below the burrow finds) with dips of 14°N. on 92° E of Mag. N and 20° N of 69° E of Mag. N there. At the tip of that talus cone (above the burrows) there was a 100 mm thick conglomerate band in arkose defining a dip of 39° N on a strike of 82° E of Mag. N. A considerably thicker, 1.2 m thick conglomerate was situated stratigraphically above these sandstone in the N.E. corner of the quarry, probably 27 m above the lowest upper shale beds.

I first visited the quarry, in March 20, 1976 with assistance from W.G. Hardie, to look for small shelly fossils by the same method as I was finding them in similarly barren-looking sandstones and conglomeratic sandstones in the upper part of the Cambrian Hartshill Quartzite. With a later 4.6 kg sample from the upper 0.1m of the 1.2m thick arkosic conglomerate on the north-east side of the quarry, and 2.75 kg of pure white quartzite of one mm grain size from near Whetly Lane below the Silurian Rubery Sandstone, my sample of rock surfaces viewed under a binocular microscope at x17.5 magnification had a mass of 18.3 kg. It consisted of rock chips split on a fly-press used to sample Ordovician brachiopods to cuboids in the 2 to 3 cubic cm size range. They proved to be barren of fossils but it is instructive to calculate the freshly exposed surface area studied. Since all the chips consisted of the quartzite, rather than shale and mud, it is reasonable the divided the sample mass by the density of the quartz or feldspar (2.6 g/ml) to deduce the volume of the sample and hence the number of chips of a particular size studied.

18.3 kg/2.6 x 1000 = 7038 cm³

Therefore:

2350 chips of 3 cm³, 3019 of 2 cm³ etc.

Actual chips from the quarry sample were measured up in mm and these volumes were found to correspond to areas split parallel to bedding of 6.3 and 4.0 cm² respectively. Adding in the sides of the chips the total viewed area was about 3.5 m²

The lowest bed seen and sampled in the continuous section of March 1976 was a shale parting yielding chips of red sandstone split along planes of 0.8 to 2.0 mm muscovite. The average diameter of the feldspar was only 0.1 mm but this sample of 1.0 kg mass yielded one smooth ellipsoidal nodule or pebble of 3.5 mm length and numerous 0.2 mm rounded green grains which looked more like marine glauconite than altered volcanics.

The overlying sandstone bed of 390 mm thickness and 2.235 kg sampled mass had a parting 120 mm from the top and had a flat top covered by the next shale band reviewed below. This sandstone showed common glauconite grains in the 0.3 to 0.5 mm diameter range, rounded muscovite flakes ranging up to 2 mm in diameter and chlorite flakes of a similar size. The feldspar grain size was 0.2 mm. The mica produced a rather laminated rock, but in the field it looked massive with vertical jointing.

The overlying shale band of 70 mm thickness and 3.0 kg sampled mass was actually a complex unit consisting of an upper sandstone of about 10 mm thickness with a flat base and convoluted top bracketed by shale. Below this there was a thicker shale with a smooth surfaces on a lenticular 10 mm sand layer within it. When broken up the feldspar grain size was 0.1 to 0.3 and the muscovite and chorite 0.5 to 0.9 mm. Glauconite rounded grains were present at much the same size as the feldspar and scarce compared to the lower beds. There were white irregular patches, best interpreted as diagenetic veining rather than trilobite debris. The most interesting feature were grey shale clasts of 10 to 20 mm length, with a rounded lenticular shape in plane view and a thin flat sheet-like form in section. These mud flakes had evidently been ripped-up from a compacted mud layer and then rolled at their edges without distortion, producing skid mark lineations seen together with load casts in the sandstone at the top of the bed, and on the base of the overlying thicker sandstone reviewed next.

The sandstone above had an overall thickness of 900 mm before the next grey shale band was reached, but I only sampled the lowest 300 mm (4.0 kg) defined by a planar parting above and by an irregular, but less convoluted base below. The feldspar grain size was 0.2 to 0.3 mm, including some angular grains and scarce larger quartz grains of 1.0 mm were now present. The resulting rock was a pale red to grey quartzite, with very little shale or glauconite present. Probably this type of sandstone continues upwards in Bilberry Hill Quarry. The shale bands seen in the lower beds are rare above the channel. Towards the top they are associated with bands of coarser quartz and feldspar, as red distorted mud flakes from probable sun cracked intertidal mud flats. My upper samples consist of one of the grit bands (probably the one above the only talus cone yielding vertical burrows in sandstone) and the tip of the main conglomerate overlain by two metres of weathered rock and soil. The conglomerate included cm-sized volcanic clasts which were showed facets as in dreikanter from deserts and the distorted type of mud flakes. The grit band was composed of rather angular 0.5 mm quartz sand, with maximum dimension of 3 mm and larger volcanic fragments.

My collected sample of red burrowed sandstone was of lenticular shape with 0.2 to 0.8 mm diameter feldspar and muscovite grains, between two partings showing the vertical shaft to be at least 50 mm height. The lower surface showed the sandstone deflected downwards into a 7.3 mm diameter burrow, split at 4.4 mm diameter and 1.5 mm below the parting by a fracture of a sand-filled shaft. The upper surface was a saucer-like, 12 mm diameter depression, containing a pair of poorly defined central rings around the 7 mm shaft. This saucer appeared to have been truncated by a thicker but missing clay drape. It was not an Arenicolites-style entrance. There was no sign either of storm generated laminae in the host sandstone, or of the other shaft. But the distance of the shaft to the edges of the sandstone blocks were only 12 to 22 mm. This is not great enough to disprove the existence of the other shaft of an Arenicolites. In my sample from the Tuttle Hill Member, the enlarged entrances of 15 mm expanded diameter are spaced 22 mm apart in terms of the middle of their 5 mm diameter shafts. An identification as Diplocraterion can be discounted. The scarce occurrence of the burrows is itself a point of difference with normal Scolithos occurrences in Anglo-Welsh Ordovician sandstone. No others were seen outside part particular talus cone. Several doubtful paired shafts structures were observed, as well as considerably more common, subpolygonal ripped-up mudstone flakes from sun cracked surfaces.

Nautiloid shell calculations

2010-05-31T11:16:00.000-05:00

Since the view of the middle whorl of the Cimomia shell from Kingsley Wood was tangential the breadth of 63 mm measured near the umbilicus is about five chambers and a quarter whorl beyond the smaller septum seen to have edges in the median plane of symmetry 21 and 45 mm from the axis of coiling. The whorl expansion rate W = 45/21 in 360° when converted to a natural logarithm and multiplied by 0.25, and then used as an exponent of e = 2.17 etc. will predict the subsequent increase in breadth and therefore the likely true breadth of the hidden small septum (i.e. it is 63/1.21 – 52 mm). By the same calculation, but going backwards for half a whorl, the radius 45 mm is reduced to 31 mm. The shell diameter is then 45+31 = 76 mm where the breath is 52 mm and the median height 45-21 = 24 mm. One can, however, see that the next whorl expands less and this can be measured as W = 97/63 more reliably than on the partly missing venter (r= 68 mm or more). Using the lower rate the breadth corresponding to a diameter of 76 mm becomes 56 mm or about 74%. Using these revised measurements the shell looks a more normal shape, but still develops a depressed and slowly expanding outer whorl with a more semicircular cross-section. The following museum specimens of Cimomia imperialis are of that variety, if clearly mature with more closely spaced final septa, with relatively pyrite-free calcite rim cements for probably Highgate material. The mature shell of 82.3 mm diameter and 57 mm breadth is labelled Highgate IPM B2155g in the Paris Nat. Hist. Mus. The only specimen, which I saw in Saffron Walden Museum, is almost certainly the one from G.S. Gibson (1818-1883) listed as “Nautilus centralis from Eocene Higate”. It showed a breadth of 59 mm at 65.5 mm. Oxford University Museum specimen 595/2 had no locality but was an old donation with measurement 63 mm at 80 mm. Other specimens from the pyrite-filled variety of Highgate septaria and Essex division E sites on the M11 and M25 are considerably larger, and become more not less compressed on the outer whorl.

Kingsley Wood Fossils Rayleigh

2010-05-31T11:15:00.000-05:00

On April 6, 2010, I visited the cutting of the London Clay Formation near Kingsley Wood in Rayleigh on the Southend Arterial road (A127) for the first time as a pedestrian. My first memories of the site were provided by the moving ‘city coach’ from Grove Road in Woodford to Southend in the summer of 1953. Since I seldom went that way since and the novelity of the scene declined, the visual images must date from then. Looking from the north side of the coach, there was a succession of wooden posts supporting power lines beside the cycle track in the plain, which gave way to woods and a curved ascent below a bare slope with yellow sands at the top. Looking the other way, with more difficulty, the traffic returning from Southend was to be seen down below beside woods.

On July 7, 1966, on a school coach ride from Southend to Portsmouth armed with the British Geological Survey 10 miles to the inch map of England, I made the following initial comments in my notebook: “Eastwood London Clay, Progress Road,….Rayleigh Weir, Bagshot sands, farmland arable.’’

Before 1922, the Ordnance Survey mapped a lane rising from 144 feet O.D. (44 m) at a bend in the western plain mapped previously by B.G.S. at the base of the Bagshot Beds, past 164.6 feet (50 m O.D.) at the lowest corner of Kingsley Wood, where later B.G.S. maps mark the base of the revised boundary termed lower Claygate Beds (Bristow et al. 1980), to an eastern summit height of 228 feet (69 m) on the only part of this lane which now exists. It is now a footpath between the west end of Kingsley Avenue and the eastern end of the south cutting made in 1922-3.

It must have been here, where there is a modern O.S. spot height in the A127 road surface 60.4 m O.D., 110 m N.W. of the end of the cutting at the truncated lane, that Eocene fossils were dug up by spadework in 1922-3. The present south cutting, now mature woodland with soil cover, was made then by loading the clay directly on to narrow gauge railway waggons, transporting it along what is now the south cycle track to an embankment in the western marshy plain. According to the resident road engineer, Mr. Thomson, “all the fossils come from one thin bed which was encountered at the base of the cutting at the highest point of the road (200 ft. O.D.)” (Wooldridge & Berdinner 1925). This is not literally the highest point, which was at around 230 feet beyond the cutting where the unweathered partly pyritic and largely uncemented marine aragonitic shell would not have been preserved. However, it is also not at the Grid Reference TQ 7940 8986 cited for the fossils by Bristow et al. (1980), about 150 m to the N.W. on the upper slope of the north cutting.

A photograph taken around 1930 from the end of the truncated lane shows both cutting with a thin cover of grass and denser older vegetation on a 2 m bank starting at a lane on the west end of the south cutting (photograph 108 of Lane & FitzGerald 1991). That marks an old field boundary, since removed and on my visit consisting of a small extension of the cycle track with barren brown clay and bricks dumped in it. The opposite side of the road is seen in profile on the photograph slightly nearer to the camera as a steep rise, followed by a more concave grass slope rising at about 55 m O.D. into a more gentle slope still covered with a line of dense bushes then not removed. Above them was the power lines remembered from my youth and present in 2010 on replaced poles running across a cleared corner of the enlarged 1938 cutting (from posts 13 to 15 on the edges of it). Slumped orange sands and clays are present in that corner of the cutting rising to the 70 m O.D. contour line. It was made in 1938 to add a north lane and cycle track up to 2m above the south lane of the A127 on the curved illustrated slope, removing a lower part of Kingsley Wood (not appearing to have large trees on it in photograph) and the upper line of bushes running eastwards.

My interest in visiting these cutting started on March 17, 2010 when I was shown a Cimomia imperialis (J. Sowerby) aragonite nautiloid shell, collected there in 1922 by W. H. Borke. He worked for the Rayleigh Builder J. T. Byford rather than as part of the labour force travelling from London on this Government make-work-project. The outermost septum on three half-whorls of the internally unbroken, hollow phragmocone, had an undistorted breadth of 97 mm, an incomplete venter to coiling axis radius of 68 mm. The next whorl had corresponding dimensions of 63 mm breadth half a whorl beyond a 45 mm radius showing around one of about 8 mm blocked by grey claystone. There measurements are adjusted in my entry on nautiloid shell calculations a height in the median plane of 24 mm. The third whorl with a radius of 23 mm showed the siphuncle between a tangential view of the septa. The 18 mm diameter umbilicus was open.

Doubts had previously been raised about the stratigraphy of these fossils, said to come from the Claygate Member of the London Clay Formation in current B.G.S. nomenclature based on Bristow et al. (1980). In the Hadleigh (Sand Pit Hill) B.G.S. borehole, only three km to the south, the glauconitic sands defining the base of the Claygate Member were 132 m above the base of the London Clay, with both pyrite and calcite septarian concretions in clays around 135 m, and sands with iron pan cementation defining the base of the Bagshot Formation at 149.6 m (Lake et al. 1987, p. 70-71). But according to a reliable well record, from Burches Farm in Whitaker & Thresh (1916), marked on B.G.S. 1:50,000 series sheet 258/259 0.4 km west of the Esso station at the A127 opposite Kingsley Wood, the base of the pure London Clay at –68.8 m O.D. would only be about 120 to 140 below the Claygate Member and Bagshot sands mapped there. Elsewhere in the Rayleigh Hills, Eastwood and in the Southend cliffs, I had recognized from septarian calcite marker beds that mapped correlations based on similar-looking sand layers and spring lines were not correct when they opposed the well data in this way. In central Rayleigh there were three occurrences of septaria, 1) a sandy unlaminated variety weathering yellowish orange ( 10YR 7/6) around a darker brown core in the highest levels of Rayleigh Station Carpark, 2) a fine-grained claystone with an orange (10YR 8/4) exterior, around a rather dull-looking interior (10YR 7/4 – 10YR 6/4) contrasting with thick moderate yellow brown (19YR 5/4) calcite veins and dark olive grey (5Y 3/1) jointing, at 60 Love Lane, 6 metres higher than the lowest of the carpark fins and 3) septaria of intermediate grain size, with Chondrites burrows more strongly weathered out than at Love Lane and containing Teredolites borings in wood, in a thin clay layer close to the 217 foot O.S. spot height on the Hockley Road, in the new entrance to Rosedale Court. This entrance also showed dumped bricks etc. But when the adjacent field was excavated in May, it also showed Eocene clays at 66 m O.D. The Cimomia shell was only cemented by a thin film of locally hemispherical pyrite, covered by a 5 mm of grey fine-grained and internally smooth calcite rim cement, and like benthic shells seen in November 1991 in the Essex Field Club collection at Stock Street (West Ham) did not come from any kind of large claystone concretion at Kingsley Wood. However, it did seem worthwhile looking to see if the cited altitude corresponded to these markers or other features here.

On going to the area on April 10, I found that three different temporary excavations yielded samples of interest, near but not in the A127 cuttings. The highest level of Rayleigh Carpark had again been dug up and showed parts of the septaria seen before higher up the same bank with some sands and silts, above brown clays. Probably it’s this horizon which B.G.S. takes as the base of the Claygates on the A127, perhaps with a local increase in sand thickness there. I would correlate it with unit SH-11b of King (1984) and my MacMurdo Road bed. A clay ditch (less than one m) had been dug from the fence of the A127, 40 of my paces (0.84m) N. W. from the old field boundary with the clay dumped in it at 55 of my paces from the next old field boundary defined now by the edge of the Esso Station on a nursery exit. Exactly under the fence there was a relatively fine-grained and wet clay, yielding a large fragment of a septarium of the Love Lane type matching the colour of the host brown clays when wet and inconspicuous. A decayed pyrite nodule and a smaller similar fragment of probably the same concretion were found loose in the bank disturbed by the exit of digging machine. When dried the larger fragment showed a tabular exterior surface of 2-4 mm, diameter low Chondrites coloured greyish orange (10YR 7/4) like interior matrix surfaces between the open septarian cracks of 10 mm width, showing olive grey (5Y 4/1) jointing around harder 3 mm, fine-grained smooth white calcite rim cements. When broken open the claystone matrix was locally white and more generally coloured yellowish brown (10YR 6/4), with no obvious sedimentary lamination or macrofossils. The upper parts of the ditch, extending for 170 paces, was of interest in showing none of the sand layers seen slumped down below the top of it on the opposite slope.

A third sampled exposure was for new gas mains along Rayleigh High Road and included a shallower branch also of only about one metre depth into Weir Farm Road where the surface altitude can be deduced to be at 66 m O.D. from a spot height at 67.4 m O.D. on the adjacent yellowish orange (10YR 6/6) sandy ridge where Glassey Road joins the High Road. The lower excavation showed some of these sands and iron pan; but mainly consisted of a well sorted 0.1 mm diameter quartz sand, with abundant similar-sized black and scarce green grains of less altered glauconite, giving it a homogeneous yellowish grey (5Y 7/4) colour when dry, and locally black when dug up. This lithology looked like glauconitic sands at Springwater Road in Eastwood, which has previously been mapped a few metres above the base of the Claygate Beds, rather than just under the Bagshot Beds. Later in April 2010, I attempted to level across from the septarium site on to the opposite north cutting, where both loose septaria fragments and slumped overlying sand ridges were observed. The highest and most interesting concretion was three of my nominally 1.78 m eye levels about the septaria site and 59 paces from the north cycle track, about level with the lowest ridge containing sand at the higher of two bends in the Kingsley Wood boundary fence at power line post 15, five eye-levels and three sand ridges below the top of the slope along that fence trending W.N.W. – E.S. E. This septarium was stained green mainly by moss and by a decayed film of hemispherical pyrite. The claystone matrix had weathered into sharply defined one mm and 5 mm diameter burrows between thin pale orange (10YR 8/2) calcite veins. Where there was no green stain, the claystone had weathered light brown (5YR 6/4), between the greyish red to brown joint colours produced by pyrite oxidation (measured on dry clean joints as 10YR 6/6), 10YR 5/4, 5R 4/2 and 10R 4/6). When fractured the claystone matrix was still light brown and showed a section of an aragonite gastropod shell, without a pyrite cement, resembling the Scaphander polysarcus illustrated by Rayner et al. (2009) from Kent, but smooth. An adjacent fragment of a septarium matching the trace fossil preservation, but lacking the pyrite weathering staining, probably came from the same concretion. This fragment resembled the Rosedale Court septaria colouration being brown (5YR 5/2) to orange grey (10YR 7/2).

The approximate elevations of the Love Lane and lower A127 ditch septaria were respectively deduced from contours on the 1999 O.S. Explorer 1:25,000 series map 175 to be 50 to 54 m O.D. A third site outside 286 Eastwood Road in Rayleigh was estimated from spot heights along that road on the 1:2500 senses O.S. map to be one metre below the central road elevation there of c.52.0 m O.D. Other finds were in ploughed fields south of Bull Lane only rising to about 47 or 48 m O.D., some distance below the ridge and springs taken to be the basal Claygates on B.G.S. maps there. Putting this altitude data together, these septaria finds define a dip gradient around one in 282 to the north of a strike of about 113° E. of N., implying that they are about 123.3 m above the base of the London Clay when projected to the Burches well. The same type of septaria, separated by small decayed and haematite-replaced pyrite nodules in an otherwise barren 3m clay insitu face, occurs at about 24 m O.D. beside the Wilson Road Flagpole in Southend. Since that site was found my me first I have tended to call all of these septaria the Wilson Road bed and to try and deduce their elevation up the London Clay from a Southend well record of the base at –96.7 m O.D. The dip there is clearly to the S.E., but the angle is rather unclear near the potentially deformed old cliff. However, estimates from both areas around 123 m up the London Clay would place the Wilson Road bed within ten metres of the top of the London Clay s.s. at Hadleigh, in unit SH-12 of King (1984) in Kent, with the Kingsley Wood fossil bed right at the top of SH-12 if at 61 m O.D. as reported.

Further Reading

BRISTOW, C.R., ELLISON, R.A. & WOOD, C.J. 1980. The Claygate Beds of Essex. Proceedings of the geologists’ Association 91(4): 261-277.

KING, C. 1984. The stratigraphy of the London Clay Formation and Virginia Water Formation in the coastal sections of the Isle of Sheppey (Kent, England) Tertiary Research 5(3): 121-158.

LAKE, R.D., ELLISON, R.A., HENSON, M.R. & CONWAY B.W. 1986. Geology of the country around Southend and Foulness. Memoir for 1:50000 sheets 258 and 259, New Series. British Geological Survey vii + 85 pp.

LANE, E.H. & FITZGERALD E. 1991. Rayleigh a Pictorial History. Phillimore Chichester 124 pp.

RACKHAM, O. 1986 The ancient woodland of England. The woods of South- East England. Rockford District Council iii & 120 pp.

RAYNER, D., MITCHELL, T., RAYNER M. & CLOUTER, F. 2009 London Clay fossils from Kent and Essex. Medway Fossil and Mineral Society Rochester 228 pp.

WHITAKER, W. & THRESH, J.C. 1916. The water supply of Essex, from underground sources. Memoirs of the Geological Survey of Great Britain, 1-510. Pl.1-4.

WOOLDRIDGE, S.W. 1923. The Geology of the Rayleigh Hills, Essex with a report on excursion Saturday June 23rd 1923. Proceedings of the Geologist’s Association, 34(4): 314-322.

WOOLDRIDGE, S.W. 1924. The Bagshot Beds of Essex, Proceedings of the Geologist’s Association 35(4): 359-383.

WOOLDRIDGE, S. W. & BERDINNER, H.C. 1925. On a section at Rayleigh, Essex showing a transition from the London Clay to Bagshot Sand Essex Naturalist 21: 112-118.

Mammoth bones from Southend Beach

2010-05-31T11:01:00.001-05:00

My walk of May 19, 2009 was along all the Southend-on-Sea beaches at the latest high tide mark (relatively low 4.6 m predicted range). It started with the discovery of a fossil elephant limb bone fragment on East Beach near the Sea Life Centre. Although formal identification depends on the discovery of the teeth, it seems probable from the size and degree of secondary post-depositional dark phosphate cementation of the white bone, that it came from the Steppe Mammoth Mammuthus trogontherii Pohlia. Mammoth species are not generally as large as modern African Elephants, but this particular species was as large as the largest known specimens in the larger sample known to Big Game Hunters and culls in Africa. It was at least 14 feet (14.3m) high at the shoulder and yielded a more intact thigh bone (femur) from Mundesly Beach (Norfolk coast) with a length of 5 feet (1.5m) [A. Lister & P. Bahn Mammoths, MacMillan N.Y. 1994, p.24 x 68]. The East Beach fragment looks like the part of this femur, which is anticlastically curved as it expands into the base of the epiphyses. It has a transverse radius of curvature of 0.116 metres, indicative of a circumference approaching 0.73 m even on the narrower shaft. The axial length parallel to the trabeculae (spaced 1.0± 0.2 mm apart) is 125 mm and a width around 80 mm. The hidden thickness of the bone around the missing marrow cavity is 25 to 30 mm. It shows a transition from a smooth cortex to the pores with 0.3 mm sand, cemented by hydrated iron oxides. The Mundesly bone photograph suggests that a circumference in the unfolded anticlastic region near the epiphyses of around 0.73 m, is equivalent to a minimum shaft circumference around 0.55 m in a femur of 1.5 m length.

A second bone fragment came from the strandline between Walton and Lynton Roads, during a walk on June 26, 2009. This represents the more externally porous surface of an epiphysis with a radius of curvature of only 30 mm. Being less cemented it probably came from a younger Pleistocene deposits than the Cromer Forest-Bed yielding M. trogontherii and the straight Tusked Elephant Palaeoloxodon antiquus (Falconer & Cautley)[another possible source of large bone fragments]. This smaller bone fragment (63 by 38 by 34 mm dimensions) could easily be confused with the pebbles of aerated concrete building blocks often seen in the same strandline; but it differs from them in being denser than seawater and having elongated pores.

The reason why these bones occur at Southend is that gravel was dredged from the North Sea and pumped from the dredgers to reinforce the beach in a large diameter pipeline. The pipeline was moved west from St. Thorpe Hall Avenue to Southend East Beach during the summer of 2002. I visited East Beach showing underlying London Clay when this was going on in June 21, 2002. Due to the gradual process of deposition of new gravel (from east to west if my memory is correct) there are different fossils and concretions related to particular spots along the strandline, even though all of them have been dredged from the North Sea sites. One can deduce that the source seabed was a thin or partial cover of flint and sarsen gravel on London Clay containing concretions, some concretions were bored in the North Sea by the modern bivalve Barnea pendula Pennant. According to Jeff Saward, who collected from the Southend beach in the winter of 2002-3, this source area was “12 miles of Felixstowe” and yielded a mammoth tooth as well as mammoth bone to him then (see report on his talk of September 2003 by Roger Coleman on pages 3-4 of Essex Rock and Mineral Society Newsletter, Number 237, October 2003)

Outside the area between central Thorpe Bay and Southend Pier, gravel has been added from time to time by trucks from other sources, which do not appear to contain large fossils. Here the London Clay is still present on the beach and is still a source of the grey insitu finds still also available at East Beach in 2010.

Faking of Trilobites?

2009-09-04T18:01:00.020-05:00

Preservation of Triobites

P. R. Sheldon (Lethais v.21, p293-306, 1988) notes that the genus Ogyginus from shales and also Llanvirn sandstones at Gilwern Hill Quarry are an exception to the local rule that trilobite pygidial width defines a normal or slightly bimodal unskewed distribution dominate by the final or holaspid stage of growth. According to him the Ogyginus corndensis (Murchison) from Gilwern Hill are “extremely abundant:, and in a previously collected museum collection of 463 intact specimens showed a maximum width of about 97 mm and some 335 specimens in the less than 13 mm width range of small holaspids and merapids (see pl. 138 in Trilobites by R. Levi-Setti (1993 Univ. of Chicago Press, the head merely being truncated during previous splitting of the poorly defined bedding planes). But the similar-looking, later Ordovician trilobite Pseudogygites latimarginatus (Hall)

Pseudogygites free cheeks, Craigleith

does look abundant on shell beds separated by four mm thick layers of barren oil shale of the Collingwood Member of the Lindsay Formation, on the beach at Craigleith Ontario. But in this case the largest specimens are so fragmented and separated into particular layers that they are not collected or illustrated like the 20 to 45 mm specimens seen in Levi-Setti (pls. 3 and 136), H.B. Whittington ( Trilobites 1992, Boydell Press U.K.) and R. Ludvigsen (Fossils of Ontario, Part 1: The Trilobites Royal Ontario Museum 1979) from that particular site seen on my own photographs. This one shows two separated free cheeks with glabella spires and a Isorthoceras from Craigleith.

Ogyginus corndensis Murchison posterior end, Wales

Weberides mucronatus (McCoy) Acre Limst

Calcareous shales overlying the Mississippian Acre Limestone, 300 m W.S.W. of Cullernose Point U.K. showed ten pygidia and one similarly disarticulated cranidium of Weberides mucronatus (McCoy) in a cluster with an equal number of brachiopods including still articulated, pyrite-filled Rugosochonites Sokolskaya, three small gastropods, one bivalve and four crinoid stem segments. Most of them are seen on the photographed half of the split bedding plane, which is probably the lower surface of the top judging from the greater oxidation of the pyrite on that side. The pygidium marked b was therefore originally being deposited concave-up like the adjacent relatively smooth glabella seen aligned parallel to it. These shales represent a relatively near-shore marine environment, the trilobites being absent in basins. The cluster was presumably formed by waves despite the probable concave-up orientations. The pygidium marked b has a width and length around 11 mm and has broken through the calcite exoskeleton of 0.08 to 0.10 mm thickness producing a rather poor preservation on both the part and counterpart. The other trilobites were of similar size as are the brachiopods, supporting the idea of current sorting. This would explain the absence of thoracic segments presumably decayed into long narrow strips before the storm.

Pseudogygites latimarginatus (Hall) & Isorthoceras tenuistriatum (Hall) Craigleith Ont.Fragment of pygidium of larger size of 0.3 mm thickness, with same 0.05 mm pits and marginal wrinkles.

Pseudogygites & Isorthoceras, Craigleith Ontario

Disarticulated thoracic segment of 40 mm width, with pleural furrows on pleural lobes flanking 10 mm wide axial lobe with 0.2 mm thick shell covered with 0.05 mm dorsal pits.

Isorthoceras tenuistriatum (Hall) of 0.4 mm thickness with 0.1 mm transverse growth ridges

Pygidium of 21 mm width, 0.08 mm thick

This and other shell layers of the Ordovician (Maysvillian) Linsay Formation on the beach at Craigleith, Ontario, are separated by three mm thick bands of relatively barren oil shale within the Collingwood Member. Two books entitled Trilobites by H. B. Whittington (Boydell Press 1992) and R. Levi-Setti (Univ. of Chicago Press 1993) and also R. Ludvigsen’s Fossils of Ontario Part 1:The Trilobites (Royal Ontario Museum 1979) illustrate specimens of Pseudogygites latimarginatus (Hall) from this site with widths of the tail-plate of up to about 45 mm, but one from Bowmanville in a slightly different facies is seen on plate 136 of Levi-Setti with a greater width of about 61 mm on the tail-plate and about 68 mm on the associated thorax. It would seem from my photographs that specimens of that size are common at Craigleith, but being more disarticulated are seldom photographed. Since it is possible that such breakage is due to cephalopod predation, followed by resedimentation into basinal shell layers, rather than by molting as Ludvigsen proposed for the samll molts there, it is instructive to study exactly what these fragments look like. The associated orthoconic cephalopod Isorthocreas tenuistriatum (Hall), revised from Geisonoceras by R. C. Frey (U.S.G.S. Prof. Pap. 1066-P, p, P59, 1995) is too small to have attacked the adult trilobites and is represented by a fragment of similar thickness (0.4 mm) to the tail-plate on the edge of the photograph with a similar width to the black separate thorax segment of 40 mm width.

Pseudogygites separated fixed cheeks on glabella, Craigleith.

This photograph shows a pair of head fragments consisting of the fixed cheek on one side joined to the posterior axial segments of the cephalon with the other fixed cheek broken off before deposition. The posterior border of the axial segment of the larger fragment appears to be distorted perhaps because it was bitten earlier in life or because it was not fully calcified when attacked. The axial lobe width suggests the head was originally about 60 mm wide. The notch in the edge of the fixed cheek is where the eye separated molting along the facial suture as proposed by Ludvigsen, but the separation of the head from the thorax, and the irregular breakage of the other fixed cheek are not due to molting in his hypothesis. The unusual feature is a posterior margin running at an angle to the segmentation of the head and not bending back at the mid-line.

A Fake Trilobite Definitely

Fake Calymene blumenbachii Brongniart, Dudley

Occipital ring with possible predation scar

The Dudley Locust Calymene was collected when the Wenlock Limestone was mined there and often sold with the disarticulated fragments glued with local rock dust as whole specimens were rare and more expensive. This one looks odd because it lacked the free cheeks and an attempt by the collector or dealer to expose them, or perhaps find others to add there failed. The pygidium has been added in a fake matrix, which now has microscopic cracks in it, these parts being relatively common. The thorax therefore shows ten not 13 segments, divided into two sets of five, which do appear to belong together despite distortion,. However, there is a better type of glue/matrix along the sides suggesting that the thorax was added to the interesting cranidium with a probable cephalopod bite mark in the occipital ring.

Pleurobrachia - Part 2

2009-06-10T17:55:00.000-05:00

June 1, 2009

Given one change of the tank water from the sea on May 22, the Pleurobrachia continued to feed on the few available copepods until it was last seen alive at about noon on the 25th. Most of the time it lived at the surface with the two tentacles hanging below and then retracting, but when last seen it was moving down with the cillia beating and the tentacles extended below. On June 1st, the tank sediment was partly removed with the old water and appeared to preserve the corpse, which could not be seen before, as a grey triangular disc of 10 mm length extending upwards into a brown 60 mm filament in the water. It would seem that live Pleurobrachia remain at the surface by active swimming and then sink to die giving them some potential of becoming fossils despite being originally transparent and nearly all composed of water. When a Beröe cucumis Fabricus similarly arrived with the new water by accident on July 12, 2007, it was considerably more active, actively swimming up from the default position on the tank floor, where it presumably died within one day. That seawater did show flashes of light in the night, but they did not come from the moving Beröe and no light was seen at all in the Pleurobrachia water. Beröe are reported to appear later in the year because they eat Pleurobrachia, which can themselves live longer in the tank by feeding on copepods.

Sepia adults and Pleurobrachia at Southend-on-Sea

2009-05-31T18:16:00.008-05:00

May 18-20 2009
During the end of a long period of relatively cool and windy weather, coincident with relatively low high tides (neap), the strandlines of dead crabs, brown and recently grown green algae still lacked jellyfish (studied Shoebury to Leigh on 19th May). They did show an only slightly bird-peck-marked cuttlebone of 179 mm length, 68.3 mm width and 20.1 thickness, deposited by the morning tide of the 19th, with the posterior end pointing 102° E. of true north on the Westcliff strandline with that trend. A hundred m or so to the west, a corpse of a female cuttlefish was aligned with the posterior end pointing towards 94° E. of N. between two strandlines spaced about 0.6 m apart and trending 104°E. of N. Both specimens were dorsal-up, and the corpse had evidently arrived earlier during the two tides of similar, slightly higher height on May 18. When removed the shell had slightly larger dimensions of 191 mm by 69.6 mm by 22.2 mm thickness. Both the thickness and the length of the last septum measured in the median plane are a good guide to the maturity and races of these adults Sepia officinalis L. and the last septa were respectively 66 mm and 72.5 mm long. It is possible that the smaller one was the male of a pair that had recently mated in the Zostera beds of Canvey Island, but the female still contained numerous 6 mm diameter oocytes in a 40 mm diameter posterior-dorsal ovary. The jaws had dimensions of 25.5 mm by 24.0 mm width and 10.5 mm by 32.3 mm. The two tentacles were largely gone and the arms contracted and or similarly degraded, producing stranded body dimensions of about 210 by 88 by 60 mm, which sank with the shell insitu and the head jack-knifed after 3.0 hours in seawater

A water sample taken after the morning tide of May 20 at Chalkwell, was of interest in containing a sea gooseberry Pleurobrachia pileus (O.F. Mueller) which was still alive in the tank on the 21st and attempting to feed from the poor animal food supply in the water sample, with the mouth at the waterline and the two tentacles with spreading lassoe cells

Stranding of Cuttlebones

Two more adult Sepia officinalis L. shells were stranded by the afternoon tide on June 8, 2009 within 8 km of strandline from Leigh to Thorpe Bay, probably after local spawning. The posterior end of one shell with dimensions of 181 by 71.4 by 21.4 mm (septum 78 mm long) was pointing 179° E. of N., 0.3 m from the edge of the wet sand trending 94° E of N. The second shell, also from Southchurch, had dimensions of 164 by 64.9 by 19.4 mm (septum 72 mm long) and had a posterior end directed towards 121° E. of N., 0.6 from the limit of wet sand trending 99° and deposited by Force 3 winds blowing from 79° producing breaking waves roughly parallel to the wind flow. Both shells were dorsal-up with bird puncture marks ventrally. The successive orientations of the posterior end of the smaller cuttlebone were recorded as it was moved about 50 m westwards by the rising high tide before developing this higher final orientation partly covered by sand and gravel. The first three strandings were dorsal-up and defined a clockwise rotation of the posterior end 40, 20 and then 170° E. of N. at different sites in the sand slope of the swash zone. When in the waves the long axis was parallel to the wind and wave crests, but it flipped over into a ventral-up orientation from this more orthogonal orientation and then repeated another clockwise rotation defined by four ventral-up strandings around 60°, 130°, 160° and 200° E. of N. It then flipped back when out in the breaking waves and showed dorsal-up strandings of about 50°, 140° and 50° E. of N. on the sand slope, followed by 49°, 69° and then 121° on the gravel berm. Wet sand was initially 0.3 m beyond the 121° position and later spread to 0.6 m without moving it.

The 18 mm long radula of the stranded Sepia showed a total of about 60 transverse rows of translucent chitinous teeth (‘’i.e.’’ not black like the parrot-like jaws around it, or yellowish brown like the chitinous hood and margins of the cuttlebone). The taxonomically stable feature of the radula is the seven longitudinal rows of sharp teeth and additional flat marginal plates, which in Sepia all lack the jagged denticulation of each tooth seen in most octopus, squid and ammonites. The width of the seven rows is 3 to 4 mm on the concave basal membrane and consist of a central radial tooth, flanked by three rows termed lateral one two and three of increasing lateral height.

General View with mm scale

Thornback Rays stranding at Southend – March 26, 2009

2009-04-26T15:16:00.003-05:00

The morning, stormy high tide at Chalkwell in Southend stranded a large ray on March 9, and the vertebra of this specimen, or more likely others, were found at Westcliff on March 11 and Southend on the 12th. The afternoon tide of March 16 stranded an undecayed specimen, curved and ventral-up on the high water mark at Thorpe Bay. It was a Thornback Ray Raja clavata lacking the yellow tag put on by Cefas for their Thames Ray Tagging and Survival 2007 - 08 study (‘’www.cefas.co.uk’’). After that the tides were generally at a lower level on the beach, but when the strandline of the afternoon tide of March 26 was studied at about the same height, the ray was found to have been converted into a curved skeleton which had moved 140 m to the east and over one groyne. It was ventral-up and showed the thin teeth of males in a head skeleton width of 125 mm, and a now partly preserved overall length of 0.5 m. Presumably it was eaten by gulls on the beach and then moved by the ides as they returned to the same elevation.

Hummocky Cross Stratification

2008-11-10T18:56:00.003-05:00

Oct 7,2008

The photographs show a rectangular calcite cemented 0.15 m thick block of black laminated very fine grained sandstone interbanded with and cut by white bands and burrow fillings representing bioturbated clays deposited between offshore marine storms in the Eocene London Clay Formation. The block was dug up recently at a depth of 18 inches (c.0.5 m) in the front garden of Symonds Avenue in Eastwood, Essex, previously mapped by the British Geological Survey officer G.W. Green as basal Claygate Beds of Eocene age when it was a grassy field in 1972. More recently an excavation in the pavement there showed laminated orange sands and brown clays at the same depth and altitude (38 m above mean seal level). The occurrence of flint pebbles in the loose sands made it look like the local Quaternary Brickearth deposits showing similar banding elsewhere. Having a calcite cemented block of the sands, which include one 5 mm diameter quartz grain in the side, confirms the mapping of these sands as an uncontaminated Eocene storm deposit within the upper part of marine London Clay Formation. The way-up of the block was unrecorded and unclear, with fungal spores on the flatter side suggesting it was once on top in the soil and the cutting of the black sands by white clay-filled Eocene marine burrows (Chondrites and some larger ones) suggesting it is actually below. The other side of the block is absent and the adjacent part is fully bioturbated. It is probably the top of a rapidly deposited storm sand layer buried within offshore marine clays. The sandy sedimentary structures look like Hummocky Cross Stratification (HCS).

Profile of gravel ridge near dead gull in Thorpe Bay

2008-03-04T19:30:00.001-05:00

Dead Gull stranded Thorpe Bay

2008-03-04T19:28:00.001-05:00

Dead Common Gull, Thorpe Bay, Feb 8, 2008

Gull corspe stranded on East Beach

2008-03-04T19:25:00.002-05:00

Gull bones with wing feathers stranded S. Side of Boom, Feb. 8, 2008

Western End of the Old Ranges Shoeburyness

2008-03-04T19:22:00.001-05:00

View 600 m E. to Barge Pier of 1909 used to disembark first British atomic bombs June 5-6 1952 S Shoebury Common.

2007 Council notice viewed from S. on Central East Beach cliffs.

2008-03-04T19:20:00.001-05:00

2005 Shoebury East Beach, Dale Knapping's Malm Burrs c.1860.

2008-03-04T19:18:00.001-05:00

Shoebury East Beach 1930's signs on Rampart Road wall

2008-03-04T19:16:00.001-05:00

1935-9 notices on local malm brick wall of c.1860, Old Ranges, Rampart Rd.

New Anti-Boat Boom of 1950-2 Shoebury East Beach

2008-03-04T19:13:00.002-05:00

Looking along the New Boom at high tide.

The New Boom from Blackgate Road Shoebury.

2008-03-04T19:11:00.001-05:00

c.2000 Council notice on New Ranges Fence, Pigs Bay

2008-03-04T19:08:00.002-05:00

Comparison of Rayleigh and Eastwood Churches

2007-02-08T08:06:00.000-05:00

December 22 2006. Measure all the London Clay concretions seen in the exterior of St. Lawrence and All Saints Church, Eastwood in Essex for comparison with Prittlewell Priory who held it as a chapel from about 1110 to the establishment of a rector in 1248. Probably this means that the Cluniacs were given what is now the Norman Nave built a few years earlier and that no further work was done with the tithes until the independent rector added the present Tower, Chancel and South Aisle walls, described as early 13th Century in architectural guidebooks. There are some later walls and an entirely red brick 16th Century South Porch which contain no London Clay materials; the bricks probably being made for sands and flint gravels of the second terrace mapped by the Geological Survey around the brook 0.3 to 1.1 km west of the church. These bricks have a similar colour on fresh faces (10R 6/6) to those made from well sorted coarse silts and very find sands of the Eocene Claygate Member in the Rayleigh South Porch, but contain obvious white and black pebbles in old bricks of dimensions 214 mm by 105 mm by 57 to 62 mm. Associated finer-grained bricks with dimensions 226 mm by 105 mm by 47 mm also have Pleistocene-derived flints in them. The Rayleigh South Porch is said to date from just before 1497 and has a granule-grade grog consisting of iron oxide concretions, yellow laminated sand clasts and similar sandy clay flakes; all of which could have come from the Claygate Member of the London Clay exposed around Rayleigh Church and Castle. The average and more uniform brick dimensions in that porch are 218 mm by 116mm by 58.5 mm. Previously measured Rochford Church tower bricks of similar age averaged 233 mm by 116 mm by 58.5 mm, and are derived from Pleistocene silts and sands in the Rochford Buried Channel under both Rochford and Eastwood Churches. At Rochford the coarse particles or grog included by the brickmakers consists of white and grey sandy clasts of dimensions 6 mm by 5 mm presumably made from calcareous concretions or previously dried silts of Pleistocene age. The Rochford tower was built for the grandfather of Anne Boleyn who died in 1515 and unlike the Eastwood and Rayleigh Churches his brickmakers made additional black bricks of similar size to produce diapers on the red brick tower. At Rayleigh this pattern was made in or shortly after 1515 by placing black flints among the Kentish Ragstones and septaria of the Alen Chapel, east chancel wall and some buttresses. It was not attempted in the South Porch probably because it was built before that fashion had developed and it was attempted at Eastwood.

Turning now to the London Clay concretions there is just one seen in the largely hidden walls of the Norman Nave. Since it contains no thick veins on the original exterior and differs in colour from those in the 13th Century walls it may perhaps be regarded as a questionable septarian record. The average colour measured from three parts of it in the freezing fog is 5.0YR 3.67/3.33 and in a previous visit in the bright afternoon weather of October 3 2005 it averaged 6.67 YR 4.00/3.33. Two parts of it were recorded as dark yellowish orange (10YR 6/6) and blackish red (5R 2/2) in both weather conditions by holding the Rock Colour Chart colours in the same light as the wall enveloped by the grey background cardboard of the chart. A third area of the concretion was recorded as Greyish Red (5R 4.2) in the sunshine and as the reddish brown (10R 3.2) today. With more experience I think that this concretion is from the London Clay, probably from Southend, and matches the red variety seen in Leigh Church tower, the Norman walls at South Church and Sutton churches and some of the Prittlewell Priory and Rayleigh Church septaria. By contrast the London Clay concretions in the Chancel and South Aisle at Eastwood are of a different colour and provinance with an average colour of their matrix measured today from 8 fragments and 24 areas of colour as 7.708 YR 6.208/3.33, changing to 7.692 6.269/3.341 with the addition of two vein colours seen on one of them (marginal prisms 5Y 8/1, central prisms of upsplit 4 mm thick vein 10 YR 6/6). Bearing in mind how small and scarce these concretion fragments were one should not assume that they do not come from thicker veined concretions seen at Southend, or were not bored by modern beach organisms. On December 14 and 18 I revisited Rayleigh Church and recorded all the colours on the London Clay concretions in the lower external wall of the most eastern of the four bays in the South Aisle, and also in what appears to be a later wall built around the post-1394 Ragstone tower forming a thicker west wall of the western bay to the South Aisle. The eastern bay include previously fallen concretion fragments showing Eocene high spired microgastropods (perhaps Litopia sp. or Spiratella tutulina (curry) and the west wall shows some calcite replaced wood with bivalve borings of Eocene age in it (3 mm diameter Teredolites longissimus Kelly and Bromley. The claystone matrix of the fallen fragments, of both grey unweathered and red veined lithology is full of coarse silt and very fine sand in a bioturbated clay matrix. The veins all have a pale yellow prismatic margin, followed by dark orange as at Eastwood, and then when thick enough another pale layer of open scalecohedral calcite prisms with a dark surface on the open vein. In one case this dark manganiferous oxide layer was overgrown by a 20 mm diameter rostette of white barite fibers, as at Prittlewell Priory. In terms of the average colours of the matrix and jointing in the western wall of the South Aisle was 2.22 Y 6.833/2.500 (18 determinations), the new insitu measurements of east bay 8.65 YR 6.294/3.024 (85 determinations) and the December 4 Choir Vestry 10.0 YR 6.229/3.057 (35 determinations). They all show the same sequence of veins and I do not doubt that all these walls were built from the same concretions, probably present on the site and perhaps left institu in the east bay wall when the church was repaired and extended in 1394. The sequence of vein cements is most characteristic at Rayleigh and obviously produced a variable average vein colour there recorded as follows: west wall (5) 9.00 YR 6.200/4.800. East Bay (20) 0.30Y 6.100/2.900, choir vestry (4), 2.50Y 7.500/3.000. This was an exposure of highly disturbed brown London Clay with similar thick-veined septaria of grey to brownish red colour on the upper beach about 110 metres east of Crowstone Avenue on December 20th and I intend to compare the samples to these similar-looking Rayleigh and Eastwood Church septaria over the holiday when dried.

Rock colours at Prittlewell Priory

2007-01-11T07:38:00.000-05:00

December 13 2006. Visited Prittlewell Cluniac Priory to check similarities between the septarian London Clay concretions formerly exposed in the foundations of the south transept of the Priory Church and those in the south aisle at Rayleigh Church potentially built before a rector was established there in 1314. Before that the Cluniacs of Prittlewell potentially had some involvement in Rayleigh Church. Around 1164 Thomas Beckett gave them some control over the Milton manor, (now Westcliff-on-sea and eastern Southend) which was held by the monks of Canterbury for their own supplies since 959 (Canterbury continuously Southchurch, presumably the coast east of the pier continuously since 823). The supplies doubtless included division D and perhaps E London Clay septaria used to rebuild the priory church in stone at the end of the 12th Century, after it was founded with no control over the coastal manors around 1110. This priory was dissolved in 1536. Since little local church building took place after that reformation until the Victorian era it is unlikely that any of the stones from the partly demolished priory can now be seen off the site. There is, however, an old, but post-1536 vintage wall showing the priory septaria in similar weathering conditions, on the north side of the cloister. Today I measured a north facing patch of these septaria and one or two in the cross-section of the wall using the Geological Society of America Rock Colour chart as at Rayleigh, Hadleigh, Broomfield etc. A patch if relatively wet and lichen-covered foundations near where the Chapter House passage would be in a monastery cloister (i.e. S.E.) was also measured and added to previous data from the now covered South Transept near the new wall (i.e.N.E.). The septarian veins were up to 11 mm thick and composed of prismatic calcite of variable lightness value and much less chroma than either the calcitic matrix of the host concretion margins or of the similarly thick and banded veins at Rayleigh. They do in fact match the scare septaria in the east nave at Hadleigh much better than the Rayleigh septaria and require a separate analysis of vein and matrix colours during averaging. Often there are hardly any vein surface colours to be seen in a church and their inclusion makes little difference to the average dominated by ferruginous sepatarian joint surfaces, weathered exteriors showing Eocene burrows and modern marine borings by Polydora and internal exfoliated calcite claystones. This is the case in the new and rather wet Chapter House passage concretions which averaged 7.576 YR 5.485/3.273 in a set of 33 colour determinations from all the orange concretions there. The undivided data from the new wall averaged 7.754 YR 6.217/3.174; with the lightness value 6.217 increased by factors such as drying and lack of lichen to the condition seen in church walls and dried polished sections. The chroma saturation of 3.174 is slightly less because the new wall contains a more varied sample of the concretions from the priory, and the hue is shifted from red to yellow because of them and the inclusion of the calcite veins in the data set (69 determinations).
It needs to be explained that hues re averaged by imagining that the yellow-red (YR) scale continues through all the hues in a manner that produces small then negative numbers in red haematitic oxidation surfaces (i.e. -5 for hue 5.0 R) and large positive numbers for reduced iron purple-blue colours (i.e. +65 for 5.0 PB). Since most of the concretions are brownish the average is in the YR scale; but it can shift into the yellow scale Y when the matrix is a largely unweathered olive grey colour and pure calcite vein surfaces are exposed. Hues reported as such and such Y should have ten added to them when plotted or compared with averages still in the zero to ten Yellow-Red scale.
Vein surface measurements exclude the barite rostettes in the middle of the septarian cracks, which provide important provinance, clues. In the South Transept sea-worn and Polydora orange (10YR 6/6) concretions had rostette diameters of 20 mm, compared to 22 mm for the one in a similar matrix in the South Aisle Rayleigh. However, the averaged vein colours in all the determinations from the Priory site are much closer to Hadleigh and showed no more barite today.

Hadleigh E Nave veins (2) 2.50 Y 7.50/3.00

Hadleigh E Nave matrix (14) 6.4 3 YR 5.57/3.57

Priory x wall veins (21) 1.905 Y 6.33/2.38

Priory x wall matrix (93) 6.720 YR 5.96/3.56

Rayleigh Choir Vestry veins (4) 1.125Y 5.57/2.75

Bivalve Borings at Rayleigh Church

2007-01-06T07:52:00.000-05:00

December 4 2006. Visited Holy trinity Church in Rayleigh, Essex to buy Christmas cards sold to fund restoration of the building by registered charity 1069853. Also determined more colours on the London Clay Formation calcite concretions there, giving 46 determinations from the relatively old South Aisle (averaging the yellowish grey 1.74Y 5.76/2.96 in Munsell system) and the younger walls of the early 16th Century porch, buttress and flint diapers, plus a north-west extension which is presumably of 18th or 19th Century age. These younger wall concretions average another yellowish grey 0.12Y 6.18/3.02 and look like a less exfoliated version of heterogeneous concretions seen in the South Aisle. Perhaps this is because parts of the old walls from inside the church were reused in these relatively small extensions. Both parts show poorly veined and numerically dominant concretions bored by the modern marine worm Polydora Ciliata Johnston (as at Broomfield Church reviewed earlier). Polydora is more conspicuous in the relatively unexfoliated concretions between the early 16th Century red bricks of the porch and buttresses. A South Aisle concretion, fallen from a decayed part of the wall not yet renovated, showed Polydora borings of 1.5 mm U-tube diameter and 12 mm length extending from a poorly veined joint which was once open on a foreshore or subtidal wavecut platform. What appeared at first sight to be holes left by missing pebbles proved to be modern bivalve borings of 18 mm length and at least 45 mm length. These showed concentric ridges transverse to their axis. These are not seen when pebbles are removed from a soft rock or concrete. In addition, there were a modern bryozoa, presumably Membanipora, grown inside of the bivalve cavity. The sequence of events evidently started with the exposure of a wavecut platform of the London Clay Formation with a band of the subhorizontal calcite concretions worn into a pitted surface rather than the raised Eocene silt burrow fillings of radial Glockeria (seen in porch) and 1.5 mm diameter shafts and polygons (seen in all later walls). The septarian cracks, which were probably not thickly veined in the bored concretions at Rayleigh, became open and calcite-free surfaces extending as an escarpment of the platform with both Polydora worms and probably Burnea bivalves boring horizontally into the stone with a generally uniform weathered colour determined dry as the typical greyish orange 10YR 7/4 seen in churches. the similarity of the colour on the horizontal exterior, previously protected by mortar in the wall, contrasts with a local region of the bored vertical crack showing evidence of reduction of oxygen in the form of a 4 mm thick layer of pale blue 5 PB 7/2 showing no deflection around the Polydora borings passing through it. Since the bivalves had died and had their homes slightly encrusted by bryozoa before the concretion was collected, it is likely that it was displaced by the sea into a muddy foreshore before it was picked up. Probably the original site was a lower foreshore channel with dangerous riptides and the collection site was an adjacent muddy beach. This setting would match The Street at Whitstable today but there may have been similar environments in Essex in Roman, Saxon or perhaps later times before the South Aisle was built (presumably in 13th Century) but from an older church materials still being used for the buttresses etc. in c 1510 and later extensions. This brief reconstruction does not refer to the other type of London Clay concretion present in the South Aisle and new N.E. corner, except as part of the average colours. These clearly came from the Upper London clay, most probably in division D at Southend, rather than division E in the Rayleigh brick and tile excavations of post-1400 vintage. They show thicker sepatarian veins with coarse prisms of ferroan calcite including a dark yellowish orange (10YR 6/6) layer flanked by less chroma, and forming a rough surface in the middle of the cracks that in one case shows small rostettes of barite (barium sulphate) of the size seen at beach level where the coast bends between Westcliff and Chalkwell. What is less clear is whether these true septaria if the upper London Clay came from the same source as the bored concretions at Rayleigh described above. There is no actual proof of middle London Clay fossils in Rayleigh, although there is at Prittlewell and Rochford Churches in the less thickly varied material. Glockeria is seen both in division D at Chalkwell and division B in Essex, and they apparently thin-veined bored concretion noted above may just have come from the tip of a large tabular one in which the full thickness of the calcite veins is not developed. Certainly many of the Rayleigh concretions with a drab and smooth exteriors are just parts of the thickly veined ones, with a coarse silt matrix more typical of burrow-fillings in division D or E than the Glockeria and crinoid concretions of division B. The extent to which the average colour reflects a mixture of two different provinances is unclear in this more complex church building.

Leaf fall and strandings at Southend

2007-01-04T13:06:00.000-05:00

November 27, 2006. After a windy week and previous night Chalkwell beach showed a gravel ridge formed in front of a strandline of algae and diverse deciduous leaves. They included a greenish yellow leaf of the Hawthorne Crataegus monogyna Jacquin, shed by one tree in my garden from November 14 to 18 this year, and from the same tree in 1997 from November 7 to 16. Smaller Hawthorn trees and hedges still retained many yellow leaves today and in previous years (1996 and 2005) they only started to fall on December 1st and had gone within a week. Static floatation tests on the December 2000 insitu and fallen Hawthorne leaves yielded average times of 0.6 and 0.7 days, little more than one tidal cycle duration and a maximum time in a sample of 59 of 2.40 days. In the rough sea environment there is probably a long enough flotation time for these and many other deciduous leaves to cross the Thames from the opposite Kent coast (6 km) when the wind is from that southerly direction. However Oak and some evergreen leaves (i.e. Holly, Ivy) can float for over a week in tests and can come from a greater distance down the River Thames and other estuaries before being sunk or stranded. These leaves are seen in smaller numbers on strandlines throughout the year, usually after rain and in the case of evergreens, probably because of dumping of garden waste in the Thames.

A diverse leaf assemblage was studied at Chalkwell on November 28 2003 by collecting a mass of stranded algae and picking all the leaves out of it. The 57 leaves included 14 oak (12 Quercus robur L. and 2 of the local forest species Q. petraea (Mattuschka) and 30 serrated elongated leaves which may have included the other local forest tree Hornbeam Carpinus betulus L. In addition, there were 3 leaves of Poplar (Populus) which probably came from a tree near the beach, 2 or 3 Maple (Acer campestre L. and single leaves of Willow (Salix) and Horsechesnut (Aesculus). These three are common ornamental and street trees in Southend-on-Sea but seemed unlikely to have been blown into the sea from these more distant trees by the gentle south and west winds developed on the night of November 27/28 2003. Maple, Horsechesnut and a Sycamore (or Plane Tree?) leaves were observed in the strandline today and seem unlikely to have come directly from the land into stronger onshore wind.

The question of whether these leaf fall and stranding observations illuminate global warming is problematical since the botany textbooks relate the change in colour and strength of the leaves to reduced day length not temperature (i.e. via the plant hormone auxin). Looking at the common Southend street trees today (Aescules) there was evidence of still green leaves on branches of otherwise bare trees adjacent to streetlights. On the other hand, there were many entirely bare trees situated beside the lights and some retaining some leaves further away. None of the trees, except those suffering from a new disease in Horsechesnut had lost leaves on November 4, although many were partly yellow and brown by that date. Probably temperature and previous dehydration has an effect additional to that due to day length, but it is difficult to make general observations.

Septaria at Hadleigh church, Essex

2006-11-25T15:21:00.000-05:00

November 10 2006. The Church dedicated to St. James-the-less in the middle of the A13 road at Hadleigh was visited today for comparison of the London Clay concretion colours with the northern Essex church visited a week before. They were both largely Norman structures but at Hadleigh the stone was largely transported over the Thames from Kent in the early exciting reign of King Stephan (c.1140); probably as a secular defense measure by the church authorities. The eastern and western ends of the church were respectively repaired with the same and some new stone in 1854 (following collapse of the semicircular apse) and 1949 (following 1934-45 aerial bombing). A greater obscuration of the original fabric is due to the construction of a vestry in 1928 outside the northwest nave and a small wooden south porch in the 18th Century. There is no external tower only a wooden one on interior nave posts.

The first circuit of the exterior showed only one possible London Clay concretion in the lower two metres of all the old walls. The second more careful circuit provided a sample of colour measurements from ten stones and during a restudy of these particular stones on a third circuit this sample was reduced to 16 colours determined from four stones near the eastern ends of the nave and 8 colours determined from four less clearly London Clay concretions in the south wall of the chancel and the S.W. region of the nave beyond the porch. That corner included a probable glacial erractic of silica cemented, non-Cretaceous sandstone, with dimensions of 450 mm by 450mm that were larger than the Cretaceous sandstones and siltstones blocks obtained from Kent. There were also a few somewhat smaller slabs of ferricrete (iron oxide cemented flint gravel) in the south and west nave.

The largest stone of clearly London Clay origin had exposed dimensions of 220 mm by 180 mm shaped by splitting a concretion along prismatic calcite veins of 5 mm maximum half-thickness flanked on both sides by dark grey to moderate red, originally pyritic joint surfaces (5R 4/1-5R 4/4). The matrix of finer-grained calcite cemented clay graded from this colour, through paler browns and oranges, to a worn rather than a bored exterior weathered yellowish grey (5Y 7/2). Adding what appear to be beach-worn pebbles of the claystone matrix, the average colour of 16 studied spots is 6.56 YR 5.813/3.500 of the Munsell Co. system (i.e. roughly yellowish orange). The provinance is not the same as Broomfield Church as the veins were thicker and more pyritic but it is still unclear whether it represents division A3 of the Reculver-Herne Bay coast in Kent, or the division D/E boundary septaria which can still be found in Hadleigh Cliffs below and east of the subsequently built castle. The sea-worn appearance of some of the stones is of course opposed to that idea since Hadleigh Castle has old marshland separating it from the sea. But if the Kentish stones were landed at the more convenient port of Leigh and had their oyster-shell mortar added there i.e. even now a few whole oyster shells can be seen in the apse) then this objection is overcome. The more doubtful additional 8 colour determinations from four rather less weathered, silty-looking angular stones averaged 1.25 Y 5.750/2.875, which is roughly yellowish to olive grey. If it is reasonable to add them the general average from Hadleigh Church only shifts to 8.12 YR 5.792/3.292, which is yellowish orange. I suspect that the whole modern oyster shells used to make the mortar between the Kentish ragstone and other imported superior building stones came from London Clay shorelines on both sides of the Thames estuary. Some septaria were therefore collected with the future mortars up until the end of Church building with the reformation. It is therefore worth looking for London Clay concretions and recording their weathered colours etc in South Essex walls which are not supposed to contain them in published descriptions. Conversely when the London Clay concretions are common enough to have been noticed by visitors with more general interests, then they probably came from specific sites along the Essex or Kent coastline where they were gathered as building stones in an earlier period ending around 1200. There alternative perspective might be that a few concretions were like the Roman brick and tile fragments also seen in small numbers at Hadleigh Church and most south Essex churches, and came from the use of Saxon or Roman buildings as quarries in stone-poor Essex lands. A third idea, which I think is less likely, is that the insitu septaria seen now in fields such as those near Hadleigh Castle, were formerly gathered as additional building stones from each manor. Much will depend on how stable London Clay slopes were in ancient times when ploughing and excavation work was less easy than in modern times. However, it is relatively easy to test this local hypothesis by comparing the colours and weathered textures of church concretions with those found locally today.

Angel Wing’s at Broomfield

2006-11-16T19:12:00.000-05:00

November 7 2006. During the visit to Broomfield Church in Essex last Friday, it was noticed that one cluster of London Clay concretions in the nave contained borings by the modern marine worm Poydora ciliata Johnstone not seen elsewhere at convenient elevations in the walls and associated in one 130 mm by 80 mm stone with 6 mm diameter bivalve borings and insitu shells. In eastern North America, this type of bivalve or clam are given the name Angel Wing, more by comparison with the six and elongated wing development reviewed in Isaiah 6 v.2 than more speculative Christmas card illustrations with two spread wings like a bird. The bivalves in the wall building stone had bored in when it was on the lower or middle foreshore of Essex or North Kent, with rough radial ribs extending to a diameter of 6 mm at the working face and a delicate concentric ornament of growth ridges extending towards the entrance for the shell length of at least 15 mm before the stone was collected in Roman, Saxon or earliest Norman times. A complete and fully investigated shell would probably have an additional pair of small shelly plates filling the gape between the valves at the working face, or alternatively a fused similar folded structure there. It was not clear to me which species was present as juvenile and partly hidden shells in the church. Bearing in mind the age of the wall and the lack of evidence of repairs at that spot it is unlikely that the American species Petricola pholadiformis Lamarck [False Angel Wing] needs to be carefully separated from the unrelated homeomorphic English Native species Barnea candida (L.) [White Piddock] allied to the American B. truncata say [Small Angel Wing]. Petricola was first noticed in the River Crouch Estuary of Essex in July 1890 (see N. Tebble British Bivalve Seashells (1966) p. 126). However there is also a smaller English species, which although looking wider than those in the wall are are, is known from the Kent coast and provides an alternative identification. This is Barnea parva (Pennant) [Little Piddock]. There are also larger species Pholoas dactylus L. [Common Piddock] and Zirfaea crispata (L.) which also bore into rocks in southern England but which look somewhat different to the church shells.

The host rock would once have been a large concretion embedded in the London Clay below and probably partly covered by modern mud or sand above. It was then split along natural joints and a few thin septarian calcite veins either by the sea, during collection or transport or more likely just before building of the nave. One can see that the wall consists of a regular size and shape of the stones, with similar-looking fragments of probably the same original concretion placed next to each other, and the Polydora bored surfaces concentrated at the one spot in the whole wall. Unlike many other Essex walls there are no large intact concretions, and no thick-veined or open-veined concretions present. Elsewhere in the nave and older part of the Chancel there are concretions split along sepatarian calcite veins with a half-thickness of up to 4 mm and more iron-stained prisms at the edge nearest to the calcite claystone matrix. But they are not common enough to be seen with the bored material and this suggests a source in the division B, or middle London Clay of Kent or Essex, where septarian veins are thin and sparse. However, since both veined and unveined concretions are termed septaria in archaeological accounts of Essex it is reasonable to use that name for London Clay concretions regardless of vein frequency. This stratigraphical deduction implies that the concretions were not gathered from the subsequently suitable habitat for boring bivalves in the Crouch estuary or indeed the Roach and on the Thames at Southend. These are all upper London Clay foreshore sites, termed division C to E, in which even a small sample of concretions soon shows some thicker and or more open septarian veins. At Southend one can certainly find Polydora borings but often they and other marine animal traces are so common as to make the original surface features of the concretion hard to observed. This is particularly the case with museum specimens of division B dredged-up from subtidal environments at Clacton and Whitstable in early Victorian times. In all probability this mode of collection was not known to people in Roman or Saxon times and the resulting building stones at Broomfield look as if they came from a muddy foreshore in which the sedimentation rate was fast enough to limit the growth of the oysters sometimes seen on concretions in churches.

A more direct method of working on the provenance of the bored concretions is to record the colours of the pre-collection weathering zones by direct comparison with the Geological Society of America Rock-Color chart held up in the same illumination. Holes cut in a grey cardboard (N7) are placed in front of each spot on the stones. Weathering in the wall mainly has the effect of exfoliating the outer layers and increasing the lightness value. Probably this weathering was limited by a covering of limewash mortar until the Victorian era. The stones display bright colours developed in Pleistocene subsoils and later to greys modified in deoxygenated foreshore muds.

Much time at Broomfield was spent on measuring 70 individual coloured areas on typical concretions at the S.W. corner of the nave another 47 in and directly around the bored concretions. Using the conventions of the Munsell Color Company these two sets of observations have slightly different averages equal to 0.42 Y 6.314/3.286 in the S.W. corner and to 9.57 YR 6.149/2.660 in the unusual area including borings. In the rough terminology of American words the typical Broomfield concretions average as a dusky yellow and the abnormal area of the wall with borings as pale yellowish brown. At the times I noticed that one set of Plydora borings were in a greyish orange (10YR 7/4) surface, around an unusually dark core of moderate brown (5YR 4/4) which also formed a hard cortex to an adjacent unbored ellipsoidal concretion with a soft pale orange interior (10 YR 8/6). The adjacent fragment with the bivalves in it showed a similar pale orange exterior (10 YR 7/4) which had exfoliated in the 5 mm thick cortex of the Polydora borings to show the more original colour to be greyish orange pink (5 YR 7/2). Previous experience suggests that this layer was once composed of hydrogen sulphide developed in foreshore muds and around empty Ploydora borings, and has presumably become lighter by oxidation in the dry wall. Inside this cortex the bivalve concretion had a very pale orange (10 YR 8/2) exfoliated matrix. Elsewhere in the wall darker brown matrix and locally red stained joints seen in the abnormal area were less conspicuous and this is reflected in the average colourations subsequently calculated.

Broomfield Church, Essex (Part 1)

2006-11-11T14:12:00.000-05:00

November 3 2006. The parish church of Broomfield, originally dedicted to St. Leonard and now to St. Mary the Virgin, lies on the ancient route from Bury St. Edmunds, via Braintree and Ingatestone, to Roman London. The parish resembles Prittlewell and Sutton Hoo in evidently being an early Anglo-Saxon administrative center, with archaeological evidence of prosperous graves situated away from the church, which was presumably avoided in the Pagan era. But perhaps the burial of people around churches is a modern custom developed when the church took over administrative functions and in other parishes, such as Ingatestone, the site of the moot and gathered tithes? I visited Broomfield today to see whether it resembled Ingatestone and Braintree Churches in showing a large stone of Saxon-era significance along the road, and to study the Eocene London Clay concretions present in the walls of many older Eastern Essex churches and castles. According to the Inventory of the Historical Monuments of Essex, volume 2, by the Royal Commission of Historical Monuments they are erroneously described as “lumps of brown boulder clay” embedded in most parts of the church with “flints and short courses of Roman Brick.” The historical dating in their account is doubtless more correct and shows that the round early 12th Century west Tower lacking the London Clay concretions was added to their concentration in the south wall of the Nave and western Chancel built in the 11th Century (i.e. perhaps Saxon or earlier Norman). The Tower was presumably built with the similar one at Great Leighs, 6 km to the N.E. and off the old road, by visiting builders who employed the superior building stone of flints for their work, and perhaps brought it with them to both sites. However when the church was enlarged to the east and north in the 15th Century and modern period the London Clay concretions were used again, and this was also the case in the “modern” South Porch of the Royal Commissioners. One can easily imagine parts of the old wall being removed to make extensions and then that stone being used again partly to save transport costs and partly to match the colour and texture of the existing exterior. However, the part of the northern walls added since the Commissioners Report, which we would term new if modern is defined as post-1714, has much the same appearance without including any London Clay or Roman materials in it.

I intend to add a technical account of the colour and fossil content of these particular London Clay concretions in the Nave as a later entry to the blog. The typical material was studied on the west side of the porch among Roman Bricks or tiles. One of the Roman bricks was easily measured on the S.W. corner quoin there as having square dimensions of 290 mm by 290 mm, with a variable thickness of 35 to 45 mm, and having a no interior black reduction band on display. These were, however, seen in smaller fragments of probable Roman tile in the main part of the Nave walls. Flints with a white patina and various rather scarce sandstones were also present, but it is London Clay concretions that dominate and is the “stone that is weathered a strong mustard yellow” in the description by Norman Scarfe (A Shell Guide to Essex, Fuber and Fuber, London). Probably these concretions and the Roman Bricks are derived from an earlier Saxon structure on the site, which may have been built along the route when St. Edmunds boy transported to London or in the remote period of the Saxon gravegoods. Prittlewell Church certainly existed, and was modified, around the time of the early 7th Century burials, without them being shifted towards it. What I did notice was that a large stone was indeed present as expected in the Nave wall at Broomfield, and projecting about 400 mm south from it. It consists of 90 mm long, white and other irregular flints cemented by hard ferricrete or perhaps even silica, into a Puddingstone (sensu Royal Commission, but not the Hertfordshire Puddingstone of geologist’s). The resulting boulder has a diameter of 0.4 m and a length of at least twice that extending to secure it in the Nave wall just west of the 14th Century S.E. Nave window. Perhaps it had functions at that time as a table for alms given to the poor, or as a mounting block for horse riders on a lower ground level? The various studied descriptions of the Church do not note it at all. However, originally it may have been where tithes and manorial obligations were made in a moot operating in the northern half of Chelmsford Hundred, in a similar way to the Kings Hill gathering at Rayleigh and at the Ingatestone.

Winter arrives in Southend.

2006-11-10T13:57:00.000-05:00

November 2 2006. Media reports from a lightship in the southern North Sea at 4 Hrs. G.M.T. indicate that the drop in the temperature of my experimental seawater tank was able to cause sinkings due to a rise in barometric pressure after variable pressure in a gale. On the morning of October 31 the temperature was still 58½°F (14.7°C) and the pressure of 100.8 KPa was associated with a SW by S wind of force 7. Next morning the temperature had dropped to 52½°F (11.4°C), the pressure was 102.0 KPa and the cold wind was force 6 from the northwest. This morning the wind had moderated here but was reported offshore as force 5 from the N.N.W. at a pressure of 103.1 KPa. The tank water temperature had declined further to 48°F (8.9°C) causing the 8th of a set of 10 dry fallen Pinus pineaster Aiton cones to sink apex-up in the night, after about 113.0 days (length 104 mm, diameter 37 mm). Most of the sinkings due to the sudden arrival of winter took place on November 1st. During the first cold night a brown decayed 66 mm diameter apple sank in freshwater after about 21.5 days and was moved to seawater to see how much longer it would float in denser water with salt ions presumably diffusing into largely flooded, brown decayed flesh. The cork present in a bucket of seawater sank after about 2056.7 days, with the surface originally punctured by the corkscrew predictably at the base. The angle of tilt of this cylinder (46 mm by 23 mm) was 45 degrees. At 15 Hrs. the ash log in the same recently illustrated apple bucket sank horizontally after 31.0 days. It had more elongated dimensions (200 mm by 60 mm). At around 17 Hrs. a probable curlew secondary wing feather sank entirely intact and vertical after 58.2 days (length 119 mm by 18 mm vane width and 2.6 mm maximum calamus diameter). Of these only the cork qualifies as a long-term floatation defining seasonal singularities in sinkings reviewed from 37 cases in The Drifting Seed vol. 12 (no.1), p9-10. Since that report a charcoal sank on July 16 after 1548 days at 17.8°C and 102.6 KPa and now the cork as noted above. Usually the annual cooling event is from November 14 to 19, but there was one previous sinking at this time of year in my data set. This was a pumice stone sunk by 7 Hrs. G.M.T. on November 2 2001 at a higher temperature (13.9°C) and pressure (104.0 KPa).

These events took place during a period of low actual and predicted high tides at Westcliff to Chalkwell beaches. The morning strandline of October 31 was predicted to be 1.8 m above mean sea level at 5.27 Hrs. and was briefly studied at Westcliff around 13 Hrs. The strandline had by then been modified by sand blowing along it from the west but was still well defined by strings of Fucus, Zostera and reed tops bound into spiral bunches. Whiteweed (Serturlia) was present from the lower intertidal zone exposed to the gales. Paired Mytilus and Cerastoderma shells had stranded. A few green Halimone leaves were also observed. They would have been able to remain floating since the tides reached their higher level on the intertidal zone around October 25.

Many Halimone leaves were deposited with Fucus, twigs, gull feather and seawater on the Westcliff promenade by the O.44 Hr. G.M.T. tide of October 23. The predicted height of this tide was 2.7 m above mean sea-level but the debris was much higher than that and the waves probably removed the Halimone leaves from insitu plants at that time. It also rained later that day and not much since then, so that the buoyant yellow-red apple stranded with a few leaves on October 31 had probably also been in the sea for a week. This stranded apple was damaged on one side, probably by falling from the tree rather than by stranding on weed and sand. It was collected and refloated in seawater on the beach and has remained floating in the tanks, stalk-up since then.

The visit to Chalkwell beach after the similarly low morning tide of November 1st showed that a live Brent Goose had returned from Siberia and was swimming in a tide that was only slowly retreating from a poorly defined strandline. Presumably the north wind had prevented Fucus and other buoyant materials from stranding on the south-facing beach. Even the algal concentrations on the west side of breakwaters may have arrived earlier with the westerly gales and similarly low high tides. However, the new patches of gravel near the top of the wet part of the beach sand were associated with a few gull and oyster catcher feathers, which had stranded recently.

On land the birds now seem to go about in one flock; including one Wren, Blue Tits, a pair of Blackbirds, House Sparrows and even an aggressive Robin. Perhaps the gardens are normally now so full of parking lots and decking that the birds need to protect each other from cats and hawks by moving together from one exposed bird table to the next? Before the cold wind, and as recently as October 27th (and again on Nov 9th) there were more solitary visits from the attractive large Red Admiral Butterfly Vanessa atalanta. At 9 Hrs. G.M.T. on October 25 a bold large fox nearly walked into me in the urban setting of Lansdowne avenue Chalkwell, near the busy A13 road. It decided it would retreat behind a parked car before going on over the street, which was not displaying any garbage, bags that day. As far as the leaf fall is concerned, one ash tree has now (November 2) lost all of them while the one next to it resembles the local Hawthorne and oak in still having an insitu and largely green leaf displays. Frogs still sing in the day and hedgehogs still scream in the night last week.

Floatation of Tilia leaves in seawater

2006-11-09T14:13:00.000-05:00

October 25 2006. According to various botanical books the structure of a deciduous large leaf consists of a waxy epitheluim which keeps gases out except via pores (stomata) on the lower paler green surface. These stomata close to prevent water from moving through them, and are adjacent to a lower layer of cells between an air cavity space termed the spongy mesophyll. The upper half of the leaf also contains some air between more continuous palisade cells, and had a darker brown colour between the supporting veins on a yellow fallen Tilia which sank first. All of them looked more transparent and yellow near the black veins and more brown and opaque on the upper surface between the veins when later dried-out. But it is still rather unclear why some of these yellow fallen leaves sank quicker than in those in the green parent condition and the others much longer despite being more damaged. Probably the larger air spaces contract and the replacement of the water held inside the palisade cells by more salty water that prevents or slows their decay to producing brown opaque bacterial/fungal material. Certainly the experimentally sunk leaves did not look more altered. It must therefore be presumed that the uniform brown colouration of stranded leaves seen today (Oak and various others not Tilia) developed on land, or during drying on mudflats etc..

Tilia leaf

The example of a test of leaves was started on October 17 with the collection of 10 yellow fallen and 10 picked green Tilia leaves at Braintree (west of the southern end of New Street and fallen on to a parking lot). After five hours in a plastic bag they were floated in all the recently illustrated buckets and tanks of seawater. A brown set collected on January 30 2001 was dried between newspapers before being similarly tested 26 days later.

The sinking of these leaves in buckets and tanks did not appear to depend on water quality. It involved estimation of times when they sink in the night, or between observations. My method has been to stay up for the first and last sinkings of a set, if sinking looked eminent, and not worry too much if the sinkings around the average had to be roughly estimated. Usually I have studied undried leaves so I was not satisfied with the seven previous Tilia times from dried brown and decayed material. The results for the tree sets are as follows (latest at 15°C):

Brown (7) Av. 6.67 days (range 0.847-10.124)

Yellow (10) Av. 2.1165 days (range 0.811-6.679)

Green (10) Av. 2.178 days (range 1.654-2.694)

The average dimensions of the green set were 85.9 mm by 78.5 mm width on the leaf itself, and 126.8 mm inclusive of the peteole or stem. The largest actually sank fist and had corresponding dimension of 128 mm by 123 mm, and 175 mm total length. The yellow set provides a more natural sampling of the leaf fall and averaged 67.0 mm by 61.8 mm width, with a total length of 96.0 mm. The largest leaf was the last to sink, probably because the peteole was shorter than the penultimate sinking of one with the same overall length of 130 to 131 mm in 3.047 days. These two yellow leaves respectively measured 80 by 68 mm width and 93 by 74 mm width on the leaf itself. Where the leaf was longer on the sides than along the central vein I measured the later, and where damage to the tip had occurred I estimated this length. The damaged leaves actually had averaged times and were relatively small, but the two longer floating yellow leaves did look thinner and paler on the upper surface when finally dried-out.

Incidentally, I am not sure which species this downtown Braintree belongs too. Judging from the larger leaf size, it would be Tilia platyphyllos Scopoli; but the hairs on the lower side of the leaf were confined to vein branches as in the hybrid between it and the Nature north Essex Tilia cordata Miller, termed Common Lime or Tilia x europaea L. In Germany the genus in termed Linden and in eastern North America Basswood. But Linnaeus, probably following the Braintree/Notley resident John Ray, correctly identified it with Tilia of Virgil and Ovid. Presumably the downtown Braintree tree is not old or Native enough for Ray to have studied it himself.

Tilia platyphyllos

Drifted L.E.C.A.

2006-11-02T15:20:00.000-05:00

October 14 2006. The Light-weight Expanded Clay Aggregates (L.E.C.A.) found stranded on Chalkwell Beach on October 9 and sampled coming in with the tide at Westcliff the next day correspond to a sentence by G.C. Cadée in his article on Texel beaches in The Drifting Seed vol. 11 no. 2 p.5 (Sept. 2005) namely “building stones of this expanded clay are made and those much larger stones one can find also in drift on our beaches.” His report was mainly about 7 mm spheres found there, with yellowish surfaces around dark purple coloured shallow cracks. both were made by calcination of the middle London Clay Formation at 1200°C in the LECA (G.B.) pits and factory at Mill Lane, High Ongar, Essex c. 1968-1995. However they are potentially made from various clay sites around the world and I have assumed that the Ongar pits ran out of clay, at least from there. On taking both the drifted material and part of one currently being used on a building site to a builders merchant, I was informed that they are marketed as CELLON BLOCKS but not where they are currently made. They doubtless get put into the sea either by illegal flytippers, or as part of official dumping of hardcore to improve sea defenses, and then float away!! I had not noticed them before and initially assumed that Lower Greensand Cretaceous sandstone pebbles in the recently repaired seawall had already come loose. They might also be confused with concrete until picked-up and the following description is made here for beachcombers and geologists.

As seen on building sites the blocks are rectangular with a length around one foot or 30 cm (I am not sure exactly which; doubtless 30cm in the Netherlands) with easily broken edges showing a pitted, rather than actually porous, rough interior. Two colours were seen both on the beach and on house building sites at Southend-on-Sea this week. A dry inland fragment (110 by 85 by 60 mm) was light bluish grey (5B 6/1), changing on both the submerged and the emerged surfaces to dark bluish grey (5B 3/1) after about five hours in an oxygenated seawater tank. The other type is very light grey (N8) and represented by the sample taken from the sea (180 by 130 by 60 mm worn subtriangle) given a light greenish grey (5G 8/1) colour by a thin film of algae and having dark yellowish grey colour (5Y 7/1) on the less easily coated original surface of the block. The latter look very much like clay which has been cut and smeared by a spade or mechanical digger, while the rough surface of both colour varieties consists of rather square 0.5 to 0.8 mm wide pits, between thin walls of silty vitrified clay showing a few dark spots of what was once presumably pyrite. Perhaps the blue variety is a more originally pyritic clay, or more likely one processed in a more reducing environment. One of the yellowish blocks from the beach was placed in the deoxygenated seawater bucket for two days and seen to go uniformly dark bluish grey below the waterline. This stain differs from the hydrogen sulphide staining of the wood, bone and aragonite shells on Chalkwell foreshore in being entirely lost again when exposed to dry air overnight. Both varieties have 10 to 20% of the volume above the waterline and do not appear to be sinking like pumice initially does.

Weather records on London Clay subsidence 2006.

2006-11-02T15:16:00.000-05:00

October 12 2006. The previously cited qualitative records of rain during this dry year on the London Clay illustrated (September 29 2006) can be compared to rain gauge records in decimal inches made by John Bird in his garden 0.35 km east of the photograph of Eastwood. Combined with my observations of when it rained during the day these diurnal totals can be put in order as a guide to likely flash floods in 2006:

Overnight April 9/10 0.78 (April total 1.54)

Rains until evening October 6 0.6 inch

Evening thunderstorm Sept 13 0.5 (Sept. total 1.04)

Overnight May 6/7 0.48 (May total 3.00)

Overnight Aug. 23/24 0.38 (Aug. tot. 2.10)

Continues daylight Aug. 23 0.38

Afternoon x later March 7 0.30 (March total 1.15)

Around 1hrs. G.M.T. August 17 0.23

Around 4 hrs. G.M.T. August 28 0.22

General “some rain” on June 15 0.22 (June total 0.73)

Rain x windy night Feb. 15 0.22 (Feb total 0.84)

It will be seen that much of the monthly rainfall took place on single days or nights, and often with most of it falling within an hour or so, in sudden bursts on a time-scale of a few minutes. This water then runs off the modern gardens converted into parking lots, decking and sheds, as well as roof areas, which were originally designed to similarly flood the street and sewers, not wet the subsoil. consequently most of the water forms a torrent down the street and a flash flood in the river despite improvements made to stop it overflooding the road seen in the photograph (which used to flood, but not now the river is in a deeper concrete channel). A more sustained gentle rain would have been better for reducing subsidence claims even in tradition gardens.

Looking now at the monthly rainfall totals from the same local source one needs to also consider when the hawthorn and other more substantial local trees developed leaves able to extract water from their tiny roots below dwellings (although the conifers, often more popular in gardens obviously operate all the year). The leaves have recently been falling in November and appear again in the middle of April (my diary notes April 14 2006 for a hawthorn, which I had fully removed because it was causing damage by September 10). It did not help that the first third of the year was also unusually dry (Jan. 0.68, Feb. 0.84, March 1.15), but there was some improvement in the spring (April 1.54, May 3.00) causing a large development of leaves, which partly became yellow and fell-off during the summer drought (June 0.73, July 0.29). Rain did return on August 12/13 but not in substantial amounts until the end of the month when it came in the potential flash floods recorded above (Aug. tot. 2.10, Sept. 1.04). These records are only up to October 11 but the present month is clearly relatively wet and the cracks in buildings are closing up. It is unavoidable that some trees have to be removed due to this type of dry weather and their proximity to dwellings with concrete foundations resting in the London Clay. However removal of all the trees from Essex, now increasingly covered in this way by dwellings and concrete, will contribute to climate change globally and to flash flooding locally.

In the longer-term the sea level and tidal range at Rochford will influence the ability of the river shown on the left of the photograph to discharge any rain which happens to fall when the tide is in. Before the late 18th Century there was no road there and it was termed a mead.

Stranded L.E.C.A. and apples

2006-11-02T14:55:00.000-05:00

October 10 2006. The highest predicted tide at Chalkwell, not only this year but for several others, was yesterday afternoon at 3.4 m above mean sea level, and both tides on the 8th and the 13.35 G.M.T. tide today were predicted as 3.3 m. Presumably this is due to the unusual size and yellow appearance of the Harvest moon, which was so impressive at the end of last week. Also a quarter of an inch of rain fell locally on October 5. This resulting flash flood and high tides evidently a gravel ridge, capped with rolls of algae concentrated on the west sides of breakwaters, before the highest predicted tide arrived. This ridge did not look much different this morning. It had just gathered more algae, plus a new element, Sea Purslane leaves removed from upper beaches and marches by high tides. It was more instructive to observe much the same floating materials in today’s high tide before it could amalgamate them with less buoyant and older stranded material on the beach. The material actually seen coming in floating with the tide over a studied distance of 1.7 km were two brown oak leaves, 15 conspicuous feathers (mainly gulls up to 320 mm length, but including two of the banded ?Curlew feathers discussed previously of 225 mm length); large rafts of Sea Purslane leaves (Halimione portula coides (L.), which floated for 48.2 days when picked and tested in December 2000) and sea grass (Zosteras),this became more common towards Westcliff than the Sea Purslane presumably coming from Leigh March rather than intertidal sands); much large human wood debris evidently coming from a flooded café selling cockels, but perhaps not directly and a floating building stone discussed below and a few plastic bottles and drink cans. In addition there were a few floating sticks.

Below this level in the sea was a swash zone of non-buoyant material being suspended by the waves and moved on to the beach above even less buoyant strandline material such as stones and open bivalve shells (Mytilus x Mercenaria). The suspended material included one large and one small dead Common Crab (Carcirus), brown algae and other vegetation bound into rolls along the edge of the incoming tide, one or two brown leaves of genera other than oak, a cone of Pinus nigra and a cultivated apple. Neither of these floated when taken home and tested in more static seawater, although they appeared to do so due to the motion of the waves. Apples but not pine cones were also conspicuous on the gravel ridge made recently, as was the building stone debris. They are therefore reviewed here.

At first sight one assumes the brown and deplorable state of the apple is due to the work of the sea, and seabirds, while it was gradually becoming non-buoyant on the intertidal mudflats. However, both the pitting and brown to black external colouration matches an apple of the same size and shape picked from the wet soil inland today. They even turned brown when kept dry and away from Magpies, after a few days indoors; while these placed directly in seawater look unaltered and can float well (as do the brown previously decayed type). The drifted apple had an equatorial diameter of 55 mm and a height diameter of 42mm, on a short stalk. One side was black and crushed, and corresponded to the bruised zone caused by landing inland. Stranding in the swash before collection produced radial cracks, which lost air when refloated. The only significant differences between the two brown and pecked apples were seen after cutting in half. The stranded one had flesh of the same orange colour, which was firmer and non-buoyant in seawater, and the core lacked seeds. It was not clear why the seeds were missing although insect borings along the stem might have been missed in such a decayed structure. Clearly the stranded apple was a red to yellow variety of Malus domestica Borkhausen which is unlikely to have been sold to the English public in that state and probably came from rejected garden waste, or in a flash flood (they do float in tap water for over a day even when brown and from wet soil). Obviously the many apples seen on Southend beaches earlier in the year have just been rejected from lunch boxes, being out of season and quite undecayed. Tested Crab Apples float much less well and probably cannot reach the sea in rivers at all (see also photographs taken October 7th).

Coconuts and Pinecones

2006-11-02T14:51:00.000-05:00

October 8 2006.

coconuts and pinecones

A second pair of photographs taken yesterday shows dried pinecones and coconuts at slightly different angles and illuminations. The bowl shows Pinus nigra cones dried-out after having sunk recently. The greater size of the now fully dry pinecone stranded at Chalkwell on April 7 2006 is illustrated by placing it beside them on the bottom left hand side of the four coconuts. Probably it is Pinus pinaster Aiton, with the apical scales fibrous and partly missing by the combined effects of maturation on the tree and beach erosion, prior to the final episode of marine transport from an unknown (English?) beach. Two of the coconuts also stranded in the Southend-on-Sea area, probably after being released into London canals for Hindu Rituals. The one on the top left stranded at Thorpe Bay during a S.W. gale at 16 hours. G.M.T. on January 13 2004, and shows a triangular mass of coir fibres truncated into a 10 mm diameter facet by Man rather than a natural erosive process in the Gulf Stream. It was then floated in the illustrated bucket, without drying during collection or major weight gains until it was removed on July 12 2006. During this time in the bucket the mass decreased from a maximum of about 806 g to about 673 g, and the orientation changed from coir-apex down to horizontal, presumably because the endosperm white flesh of the coconut gradually decayed. Certainly it now rattles about in this new even less dense dry state. One of the eyes was open enough for air bubbles to exit it when collected. An old water line in the bucket experiment can be hopefully seen on the photograph defined by a white band with a chord diameter of 80 mm on the opposite end of the nut from the coir fibres around the eyes. The overall length is 170 mm and the equatorial diameter 110 mm.

The stranded coconut on the top right is the one discussed on this blog and was found near Chalkwell Shelter on April 2 2006, with the husk separated and one of the eyes which had been covered by it seen to have a tunnel of white endosperm below it. In this case the husk looks more extensive than that seen usually on sale in England.; but might presumably have been imported for a Hindu niche market. I wish I knew exactly how Hindu’s prepare their coconuts for ritual refloatations and when. The usually cited and observed canal and coastal rituals are roughly in August and not when I see strandings at Southend. Natural drifting with the Gulf Stream is possible but would seem likely to produce more evidence of marine encrustation. Illustrations of stranded coconuts at intermediate sites would be instructive if they show what form the husk has after being floated by hurricanes etc.

The two lower coconuts were purchased from an English supermarket, where they are sold with less husk present than in some Green grocers shops. They are coconuts A (left) and B (right) of my notes in The Drifted Seed 2005 and 2006. The photograph is mainly of interest in showing that coconut B has become black during a second summer of drying after having sunk in seawater. The other coconut A shows the colouration after drying for just one summer and when any coconut has been in seawater for a day or so it is dark brown. In terms of mass changes in coconut B, there was an increase from about 550 g when purchases., to 620 g just after it sank and 644 g when drying started on day 626 of the experiment. Dehydration and perhaps some decay reduced the mass to 339 g on day 802; but after the nut became black again and leaked green copra oil from the eye the mass was further reduced to 259 g on day 1100 (which was just prior to the photography). Curiously when half-coconuts are left exposed to the air and not eaten by birds the flesh seems relatively stable at English temperatures.

Various buckets and tanks

2006-10-21T12:33:00.000-05:00

October 7 2006. Photograph the various buckets and tanks used for floatation in seawater experiments and also the now dry coconuts and pinecones. Various items and topics are reviewed here. In experiments involving fruit and wood a white bacterial film grows on the surface of the water and these objects even with frequent aerations or exchanges with new seawater. Probably sugar solutions exit the fruit and feed the bacteria, which then deoxygenate the water if they die and sink to the bottom. In addition materials such as wood and pinecones eventually stain the water brown and also make it form a foam when shaken-up, which then inhibits oxygenation. One pair of photographs, in different lighting conditions, shows a relatively new seawater on the left with apples in it and an older seawater with only less active materials present since this right-hand water was previously used to float apples and has been stained slightly brown by the pinecones.

two pails

In it there is a greater quantity of white bacteria present. What is odd is that only the nearly emergent tops of these and other pinecones are stained white while it is the submerged upper parts of the wood and apples, which develop this white film. To some extent it just defines a waterline on inert materials, such as the plastic bucket and floating coconuts; but on the cones it also extends higher than this level film. Consequently when coconuts are removed and dried one can see a waterline of white or grey bacterial and algal staining present where they spent most of their time floating, and this also provides clues in Nature about drifting orientations on shells since I have recently cut some wood in the garden, due to the drought/subsidence problem outlined previously. It was interesting to compare the densities of instantaneously cut and floated wood in their summer state of moisture. Hawthorne logs sank straight away in seawater, but samples left ash cut ends on the tree before further cutting sometimes floated for a few minutes. Elder wood generally sank instantaneous but a few samples did float without drying, but only for a few days. When that is the case then longer sections of wood, termed logs, float longer than slices cut from between them, due to rates of water and air inside the structure being involved. Also as one moves from the stem to the thin twigs, even of Hawthorne, the floatation times increase, presumably because the new wood is less dense. Thus when one considers a less dense wood such as Ash, the twigs can float longer than the logs because they are initially less dense and more liable to dry if left on the ground. On the other hand the logs float longer than smaller slices of the same density and some twigs, due to rates of waterlogging and decay being increased when the surface to volume ratio is larger in a smaller structure. In a further complication seasonal variations in moisture change both the initial density and the rates of waterlogging. The photograph shows two logs of an Ash Fraxinus still floating after 7 days, compared to one and two days for the wood slices of 10 to 20mm length which were cut off them before floatation.

2 pails

The logs have a length around 195 mm and diameters around 65 mm, representing the base of a major twenty-year old branch. Judging from previous tests done at this time of year on an adjacent branch these logs may only float in these buckets until November, while the record for Ash twigs is held by one cut in November 30 2000 that sank after 276 days (diameter 19mm, cut to 74 mm length and kept in plastic bag until floated December 16 2000).

The associated floating objects in the left hand bucket are four apples of Malus domestica Borkhausen which fell from the tree and were floated in the morning of September 8 2006 (out of a sample of 10, 4 have sunk, 2 others float in another container), a wine cork made from Quercus suber L. which has nearly sunk after being floated on March 12 2001 (it can hardly be seen in the photograph, being tilted up and almost submerged) and the last of a batch of 8 Pinus nigra Arnold cones collected and floated on September 11 2006. The other bucket shows some driftwood, stranded corks and more recently collected cones from below the same tree. The record from Pinus nigra cones from that tree is currently held by two that fell in winter and floated for 65 days after January 7 2002. This is somewhat mysterious since drier; more open summer cones might be expected to float longer. Colder experimental conditions in winter and the larger size of the cones available that day probably explain that anomaly.

London Clay and climate change

2006-10-06T15:01:00.000-05:00

September 29 2006. My diary lists the following dates when rain wetted my garden this year in the rain shadow of the Rayleigh Hills, Essex.

February 12 and particularly 15th.
March 7, 10 and 24 (minor events).
April 1-2 heavy, but short showers.
April 10 extensive rain.
May 14, 16, 20, 22 and 25 (20th and 25th extensive).
May 26, 27, 29, 30 (minor events).
June 13, 14, 15, 21 (minor events).
June 26 extensive rain.
July 5 heavy but short shower.
July 7,9,11, and 22, August 1 and 7 (minor events).
August 13 finally have significant rain.
August 17 extensive rain (minor on 21st).
August 23-24 extensive rain (minor on 26th).
August 28 extensive (minor on Sept 1st).
September 13 extensive rain.
September 22 short heavy shower.

Essex Radio had a program earlier in the week on the subsidence caused by tree roots dehydrating the London Clay terrain in southern Essex this summer. More sandy substrates do not subside in this way but during wetter years, particularly winters when the deciduous trees are not extracting water in this way; they produce springs and slumps at the junction with the London Clay. Presumably having minor sand or silt layers within the London Clay itself has the dual effect of producing a slightly steeper, stronger slope below the dwellings, and a route for tree roots to extract water from the interbedded clays in a dry summer. The tendency to cover Essex with buildings and parking lots, rather than gardens, is encouraged by insurance companies faced with subsidence claims. This in turn reduces the ability of water to wet the subsoil rather than run off down the road, drains rivers and into the sea in a few hours. During wetter weather this rapid exit of the water itself causes problems for property owners living near rivers which cannot hold the increased water supply, often supplied in short thunder storms and a flash flood. Given a larger slope with London Clay below sands or natural streams one can observe major slumps such as the Southend Bandstand visited on May 10.

Southend Bandstand - major slump of London Clay

London Clay drainage problems, Southend-on-Sea. London Clay slope opposite a river liable to flash flooding along its new concrete channel (below railings on left). Also shows a continuous spring-line above the opposite sidewalk (red warning signs behind cars) apparently from a sandy layer with the London Clay. The finer laminated clays and septaria of the Beaver Tower bed occur below it and reach the sidewalk beside the white car (5th from right). After rain the water exits about one metre up the traditional garden paths in the middle of the photograph.

Map showing Southend England.

Cuttlebone flotation times

2006-10-06T14:54:00.000-05:00

September 26 2006. Between 6.10 and 6.20 hrs. G.M.T. the last of the 25 cuttlebones found and refloated without drying in March 24 to April 3 sank in the seawater tanks. A few 10 mm long fragments of reed collected with them have remained floating, although many hundreds sank within a few days. Data for the Whelk egg cases also stranded around that time showed no correlation with their size and a wide variation on a shorter time-scale (e.g. 12 ranged from 1.6 to 54.65 days, with an average of 38.0 days). Intact cuttlebones of the same species and morphology would be expected to show a linear correlation between floatation time and length, due to the volume of gas being extracted and replaced by seawater via the porous surface area of the striated ventral chamber openings. Judging from results in my article in The Drifting Seed (2006) a large cuttlebone from the North Sea floats for four years in the test conditions reviewed here and the small shells stranded in March might float for one year or more. However, these predictions are modified by breakage and puncturing of the shells by fulmars presumably while the shell is still associated with the floating corpse of this squid-like animal. Moreover, some water is present inside the shell in life and more soon enters when they are punctured before stranding on an uncertain time-scale. Finally on arrival on the beach the shells tend to break in half and undergo further damage which makes them non-buoyant within a few days. Nonetheless the experimental floatation time is instructive as a guide to the possible transatlantic dispersal of these shells after death and presents some statistical problems due to the wide variation in observed times. In the latest test the original size of the shells is evident from their width, inclusive of their chitinous margin when intact and only ranged from 22 to 39 mm (Av. 30.4). The preserved length of these shells with a probable original length of up to 100 mm averaged 62.7 mm and the ratio of it divided by the with was more proportional to the floatation time than the absolute preserved length ranging from 35 mm (sank 14.4 days) to 96 mm (sank 122.4 days). However, the correlation was still poor, probably because the birds produced many deep punctures in some shells without breaking them. Since the sample was 25 one can remove the median result of 107.3 days, corresponding to the average of 91.0 days, and consider the averages and range in four subsets of six shells. The rapidly sunk set ranged from about 4.6 to 24.0 days (i.e. when they sank in the night, the time was recorded half-way through it) with a mean of 11.7 days and a length/width ratio averaging 1.89 to one. The next six averaged 44.5 days and 1.92 to one. The next six with times greater than the median sample averaged 128.8 days and 2.32 to one, mainly because they were more intact. Finally the six with the longest times, ranging from about 158.1 to 185.4 days average 176.5 days and a length ratio of 2.44 to one. Overall the average floatation time of 91.0 days occupied a rather rare period in a polymodal distribution with the four sunk between 182.2 and 185.4 days perhaps close to the limit for these damaged small cuttlebones?

a cuttlefish

Northern Fulmar (Fulmarus glacialis) landing on a cliff top at Hunstanton, Norfork, England. Photograph copyrighted Andrew Dunn, 18 February 2006 (http://www.andrewdunnphoto.com). This file is licensed under Creative Commons Attribution ShareAlike 2.0 License

Resurfacing of coconuts

2006-09-26T06:41:00.000-05:00

Coconut I of my experimental floatations in seawater was marketed, wrapped in plastic, as a “Milky Coconut, Dominican Republic 5711/03 class 1, display until February 8 2005”. The initial mass, inclusive of subsequently removed plastic and coir fibres was 605 g and sank in seawater in February 1 2005 at 15.30 hrs G.M.T. During the first two and a quarter hours air bubbles effused from around two of the three eyes (basal pores) when the coconut was manually inverted from the usual apex-up orientation when sinking. This air presumably came from the nut wall, via canals seen radiating from the inside of the basal pores on split specimens, since the nut exterior changed from light to dark brown in this short time. A wet mass, exclusive of removed coir fibres and plastic was recorded as 607 g after exactly 2.3 of a day in the seawater tank, rising to 611 g on days 2.6 and 11.8. After this the coconut was removed to the bottom of an open bucket used to house the rejected old tank seawater and had a mass of 607 g on day 100, 601 g on day 127 and 598 g on day 200. This water sometimes had a raised density due to evaporation before being exchanged with new water from the sea and this was 1.032 g/ml on day 575 when coconut finally had lost enough internal mass of endosperm and or milky liquid to resurface. It was then returned to the diurnally aerated tank seawater of 1.029 g/ml density where it promptly sank at a mass around 586 g. The displacement volume found by dividing this mass by the density of the two seawaters was therefore 567 to 568 ml, and the initial density when marketed 1.06 g/ml. The cited water densities are from a hydrometer only giving an exact reading at 20°C and actually recorded at 6 hrs G.M.T. on August 31 2006 at 16°C. The air temperature above the bucket had risen to above 77°F (25°C) in the later July 2006 heatwave without causing the coconut to resurface. This suggests that expansion of primary and secondary decay gases by increased ambient temperature is not the direct cause of resurfacing during a relatively cool weather. Probably the high temperatures increased the rate at which the milky liquid and endosperm inside the nut was converted into gas, but due to the still intact nature of the three basal pores and nut wall the gases merely diffused out if their partial pressures were greatly in excess of the ambient and similarly stagnate seawater. In previous experiments, reported from the fresher tank seawater in my articles in The Drifting Seed (2005, 2006) the initially more buoyant coconuts A to F all became gradually less dense during the first 200days of flotation and only then started to gain mass due to a net replacement of their internal primary and secondary gases by seawater. Coconut I is merely following the same trend but on a longer time-scale and with little or no primary air present inside the endosperm cavity when marketed. Some of these coconuts contained little or no milky liquid when marketed and evidence of loss of endosperm flesh under the basal pores before the latter became thin or open enough to admit seawater at an increasing rate in the aerated tank environment. Probably there is a similar decay of endosperm flesh into bacteria plus gas going on to reduce the mass of coconut I, and not merely fermentation of milky liquid which may have actually slowed the decay process in the denser endosperm down? It is predicted that coconut I, now kept in the aerated tank environment will soon resurface due to further internal mass loss.

My tanks.

Chalkwell Stranded feathers (cont.)

2006-09-20T13:55:00.000-05:00

September 3 and 4 2006. Chalkwell beach was revisited around noon on both these days, with predicted tides at 1.6 m above mean sea level forming a strandline of eelgrass (Zostera), brown algae and gull feather on the first morning and cut into a small cliff on the second morning. There was a southwest gale on September 2 and 3 but it was calm at the times of the high tides. The occurrence of eelgrass was a new feature, not very evident earlier in the year and doubtless resulting from the wind acting on the lower intertidal zone, about 2 km south-west of Chalkwell, where this marine grass grows in summer.

On September 3 a couple of hundred metres of the strandline showed three large bird corpses, as well as the separated barred and gull feathers seen previously. A large gull with intact head had stranded against the west side of a breakwater and two headless birds were on the open strandline further to the east. The large gull probably corresponded to the feathers of the Lesser Black-Backed Gull now added to the loose assemblage and one of the corpses was a white smaller gull represented by loose Black-Headed Gull feathers seen previously. Both these corpses had gone the next day but the third one remained having merely been displaced down the cliff of grass and sand cut by the later tide and wind. During this displacement one of the wings had opened but considerable force was required to pull out one of the primary feather of around 320 mm when standing on the corpse. This feather was dark grey with a white rhachis. This feather was not greatly different to those found loose and attributed to the wings of Lesser Black-Backed Gulls, and the smaller transverse banded brest and tail feathers match the loose banded feathers found on August 22 and later. The secondary wing feathers were paler brown, with a white tip to the more blunt tip to the vane. Due to the ongoing bird influenza cares I did not make a more careful study of the corpse and these smaller feathers but judging from the size of the largest wing feathers it is more likely to be a Peregrine Falcon than a Cuckoo, and was clearly different from the colour pattern of a Curlew. However, a Curlew option for the loose banded feathers seen on the beach was reinforced by a collection of probable primary wing feather among the gull and banded feathers on September 4. This feather showed 14 brown triangular bars on the vane and an overall length of 231 mm. Probably it is a mistake to regard the new corpse with small banded feathers on the body as the only or even the main species yielding the small Curlew-like feathers on the strandline.

Black-Headed Gull

Stranding of feathers at Chalkwell

2006-09-05T14:21:00.000-05:00

August 22 2006. A further survey of the two latest strandlines between Chalkwell station and Shelter (0.6 km) showed a return to winter debris in the form of the brown alga Ascophyllum among the summer green algae. A few large common crabs were present, a large one with legs stranded dorsal-up and more numerous separated dorsal carapaces stranded ventral-up; concave-up in terms of hydrodynamics. There were also some stranded reeds, twigs and human-worked wood debris, which had not come directly from the marshes as the latest tides were all relatively low (predicted as slightly higher, 2.5 m above mean sea-level in latest tide studies around 1 p.m.). A characteristic feature of August strandlines was evident in the form of abundant adult feathers of Black-Headed Gulls, which were also seen alive and well on the beach, and locally molt at this time. My experience is that when floated in closed plastic bottles of seawater they remain largely intact and still do not sink (since August 9 1999, molted on grass inland at Leigh-on-Sea) but in more agitated and open tanks they soon break-up releasing separated calamus, rhachis and vane fragments which can sink despite initially being hollow and full of air. On December 4 2005 I refloated both dried and recently stranded primary wing feathers of the Great Black-Backed Gull Larus marinus L, mainly cut into the calamus (quill) and the remaining rhachis plus vane, in the diurnally agitated seawater tanks. The six calamus sample had cut dimensions of 145 mm boy 6 mm diameter, and their separated vanes had lengths ranging from 213 to 247 mm. Recently a few of the calamus samples have sunk apparently unchanged, while the others have lost all or most of their vanes and distal rhachis before sinking. By August 30, day 269 of floatation in the more open conditions there were just two calamus samples still floating horizontally, with one uncut feather which is not reduced to a total length of 350 mm lacking any trace of a vane and the tip of the rhachis. By contrast the black cormorant tail feather, stranded and refloated in the same experimental conditions on January 3 2006, sank in a macroscopically intact condition on August 4 (day 212). The black melanin probably resists decay and brittleness of the white keratin, but there is probably a better adaptation of the deep-diving feathers of cormorants against waterlogging. In addition they have a greater initial density, making them sink quicker when refloated than the relatively hollow structure of gull and other more typical bird feathers. This denser structure and the melanin doubtless contributes to their lower rate of decay, which in gull feathers is due to brittle fracturing of the keratin, rather than obvious bacterial growth. However it is also possible that cormorant feathers also contain more wax or oils than gull feathers. One can of course see the cormorants standing with their wings open to dry them while the gulls and other marine birds do not bother and are much better fliers despite this careless indifference to feather drying. Terrestrial birds even go to the trouble of getting their feathers wet in freshwater, rather than worry about his effect on wing density after a bath.

The more unusual and attractive feathers seen stranded on August 22 have continued to float in the same tank until August 30 without showing signs of damage. A sample of 8, with lengths of 116 to 131 mm and vane widths of 18 to 38 mm (when dry), showed the common characteristics of 8 to 12 transverse brown bands or triangular bars on the generally white background of the vane. The calamus and rhachis were mainly white, but with a grey more translucent proximal end to the calamus, and a shore central band of brown within the white proximal end of the rhachis. It was not clear to me what these feathers were, but since they were spread out on two adjacent strandlines over a 0.6 km distance they did not result from a single drowned woodpecker or similar non-marine species. The tail and secondary wing feathers of a local wading bird the Curlew Numenius arquata (L.) seem to be the most likely candidate judging from Tracks and Signs of the Birds of Britain and Europe by Brown et al. (2003, Christoper Helm, Publisher London 333 pp.). The main problem with that identification is that the similar-looking, larger primary wing feathers, were not seen among the gull feathers of that size; perhaps because they are not molted at the same time as the secondary and tail feathers.

Incidentally the two large pinecones floated and described on April 7 2006, also sank on the tank containing the gull calamus samples on August 2-4 after slight cooling of the warm seawater.

2006-08-10T12:59:00.000-05:00

July 5 2006. The predicted tide at 1.8 m above mean sea level was studied at Westcliff during a rare morning of showers this summer. Green algae defined the strandline, rather than brown algae as in April, and there were more numerous dead crabs stranded with it. Seven were counted as white juveniles with a ventral-up orientation and five were larger green specimens with a dorsal-up orientation, of the same species Carcinus maenus L. Their legs were still present and there was no obvious cause of death, but they were not just molted carapaces. Mytilus or mussel shells were present on the strandline as clean single valves, but an oyster shell had evidently arrived with the muscle still holding the valves together in an otherwise empty shell cavity. The two valves must have then become separated by the breaking waves, being found three metres apart and then fitted back together. Most of the surfaces of both valves were encrusted with long-dead barnacles lacking their central plates. But since the winter a clean new layer of marginal growth of the oyster had been disfigured by tiny spots consisting of nearly microscopic new and intact barnacles. Gull feathers, a few twigs, a wine cork and a pinecone with algae and a flint trapped in it were the only other stranded objects seen in a quick 1 km survey of the new strandline.

Since it was found the pinecone, probably Pinus nigra Arnold from Westcliff seafront gardens, was studied with other in warm sea water and dry sunny weather. When found it looked remarkably dry despite having a position on the latest strandline, collected in damp weather. The scales firmly held a white angular flint of orthogonal dimensions 9.1 by 8.0 by 7.1 mm which had not come from the same strandline.

July 20 2006. Another Westcliff beach survey, was done over a shorter interval of 0.7 km was done on the strandline produced by the predicted tide at 2.1 m above mean sea level (9am B.S.T. studied two hours later during a day of record high temperatures, which were less extreme by a still cool sea). Green algae again dominated the strandline showing a single large Common jellyfish and an intact but spineless regular echinoid (31.8 mm diameter, 23.5 mm high with less green side less convex). Crabs were present and were larger than on July 5 and there were also two pathetic stranded gulls, with enough vitality to turn their heads and body axes parallel to and just below the line of algae. Stranded dying gulls can also be seen in winter but are not often noted and they suggest that some environmental change has taken place in the warm weather.

July 27 2006. The two large pinecones floated in seawater and described on April 7 are still floating after 111 days but smaller cones sink faster in the same tanks. For example the cone with a flint in it was dried in the present warm and dry weather on July 17 at a length of 59.4 mm and a maximum diameter of 54.9 by 57.9 mm. The flint was placed on the upper surface and was firmly held by the contraction of the scales between 10 and 20 minutes later. Full contraction of the scales, to a stable diameter away from the flint obstructing the scales of 31.9 mm, took three and a half hours. Further waterlogging sank and cone plus flint after only about 9.7 days. The diameters of 29.6 mm by 31.3 mm away from the flint corresponded to a wet length of 6.48 mm. It was then place outside in the sun at 8.10 hrs B.S.T. on July 26. The scales opened enough to release the flint (54.1 by 50.8 mm) at 14.30 hours today.

2006-07-13T13:56:00.000-05:00

June 24 2006. Continuation of reading following the visit to Ingatestone (mainly Reaney’s Place Names of Essex Cambridge University Press 1969) indicates that it is situated in that part of the East Saxon Kingdom which became Chelmsford Hundred, extending along the Roman Road from London to Braintree and Bury St. Edmunds, from the crossing of the River Wid 20 and half English miles from London, to less obviously defined wooded backcountry now termed Young’s End nearly at the 38th mile post. In other directions the hundred was not extensive, but did join the probably originally superior Rochford Hundred at the old crossings of the Crouch estuary at Hull and Battlesbridges.

Ingatestone Parish Church is one of the few situated near this route in Essex and like other exceptions is probably a late addition to East Saxon settlement which avoided Roman roads and former settlements. Later extensions of these villages around old church sites are a mile or more away on the redeveloped Roman Road and given names such as Margasetting Street, the Street in Little Waltham etc. New market towns like Chelmsford and Braintree had the original church off the road. The new Braintree church was built on the Roman settlement and directly in line with the road. It has a glacial erratic boulder incorporated into a tower built after the market opened in 1199. Widford is another church on the road. The building has apparently been even more extensively “restored”, like the rest of the exterior walls at Braintree. At Ingatestone the erratic boulder was left in the churchyard, and not reused. At the time of the Domesday Survey the name Inge was sufficient for the manors most adjacent to the stone, and the previous extended moot area given allied names later such as Mountnessing (Ginga in 1087) and Margaretting (Ginga). However, when one of the central but secular manors of Inge had a second St. Mary’s Church built on it, probably at the same time as the present c.1100 Ingatestone Church exterior, it was obviously helpful to refer to the original site where rents were paid to the nuns as Inge at the Stone. Later when King Henry II gave the other old St. Mary’s Church to Friars of Jerusalem Hospital, it became Frierning. The first known use of the name Ingatestone was therefore after the arrival of the Friars, when it was recorded as the nuns’ property Ginges ad Petram in 1254. Having gone over much of the ground himself, R. Reaney goes with Morant and the consensus and rejects the idea which he credits to the 1913 book by Wilde and Christie, linking to stone to some hypothetical Roman milestone, rather than the more conspicuous erratic stone still in the churchyard. Probably the ancient Saxons knew nothing about Roman milestones and very little about their roads, but did find the erratic a convenient marker for meetings along the old track. What has undermined this interpretation has been the previous emphasis on the erratic also being used as a milestone by the Romans. This seems highly unlikely even though their mark would have been 30 yards beyond it if they wished to indicate 25 Roman miles from London along the route surveyed for the 18th Century 22nd milestone.

2006-07-12T18:28:00.000-05:00

June 20 2006. Sand sampled from around the 85 m above mean sea level in S.E. Mill Green Common, uppermost Claygate Member on the Geological Survey maps, did not look much like that Eocene marine sand, being angular with many sharp edges at 0.08 mm diameter and mixed with only few well rounded 0.14 mm grains familiar to me from the Claygates elsewhere. In addition there were varied pebbles and even an angular cobble, with the same orange sand inside their pitting and presumably moved down the hill from the mapped area of the Old Head Gravels (which should have a clay matrix). I was, however, mainly interested in what the local pebbles looked like and made the following observations:

a) Angular flint cobble. The cobble did not look like a flint to me until I broke it open to show a conchoidal fracture of dark grey (N3) to brownish grey (5YR 4/1) colour, inside a chalky cortex of typical 1.4 mm thickness. The unbroken dimensions were 97.3 by 66.0 by 48.1 mm, with a white hard vein of chert of around 9 mm width raised above the soft cortex containing a few similarly white and raised Cretaceous burrow fillings of 3 mm diameter. The exterior of the cortex did not look like chalk, or the normally much hard cortex of Chalk flints, since it was stained to a yellowish orange colour (10YR 7/6) like the sand matrix. However, in the freshly fracture the cortex was pure white chalk (N9) and not simply a white patina of the flint mineral, which according to textbooks is a microcrystalline silicon dioxide and water mineral (Chalcedony), rather than fragmented Cretaceous microplankton (coccoliths) composed of the softer mineral calcite (one form of calcium carbonate).

b) Flint pebbles. One showed the same dark grey (N4) freshly broken interior, like the cobble and flints inside the chalk mine at Grimes Graves. Others had moderate yellow brown (10YR 5/4) to orange (10YR 6/4) colour on similarly made fractures. This internal and relatively primary colouration is masked by the variable development of a white layer around the whole surface of the somewhat flattened ellipsoids, which is evidently produced by oxidation of organic inclusions in the flint, rather than by a primary cortex of chalk being preserved on this hard exterior during transportation by rivers. In a brown flint (10 YR 5/4) which had a bluish grey (5B 6/1) exterior of 44.2 x 86.6 x 24.1 mm orthogonal diameters, the white patina had a uniform thickness of 0.10 to 0.15 mm, with an underlying grey patina extending to 2 or 3 mm into the unaltered interior. Another flint found next to it had a more mottled exterior, with orange (10YR 7/6) and blue (5B 6/1) areas, and a generally thicker patina of 0.4 mm thickness extended to 0.8 mm in pipe-like structures. The interior was moderate yellow brown (10YR 5/4) to orange (10YR 6/4). A thinner patina can therefore show the interior paler colours, if present while the thicker patina can produce a dark mottling which is not indicative of how it varies in thickness over a similarly pale interior. On the surface of all these pebbles there were irregular rounded pits, which probably result from poor silicification of the parent chalk burrows and smaller triangular pits of 0.3 to 1.2 mm width produced by impact damage and or permafrost action. Between these pits there are a variety of surface cracks, generally slightly curved and with a width of 0.03 to 0.2 mm potentially made by the grinding action of the host sand. This quartz sand is slightly harder than the flint mineral and certainly less likely to shatter on impact.

c) Lithic quartzite pebbles. One sample collected as sand yielded seven of the usual flint patinated pebbles described above from various samples and three generally smaller and facetted, highly polished pebbles of quartzite. The largest of these was more irregular than triangular in shape, but with a highly polished exterior showing impact triangle of only 0.3 to 0.5 mm width, some 0.2 mm to 5 mm wide rounded pits and abrasion grooves of less than 0.02 mm width. The orthogonal dimensions were 44.8 x 23.6 x 18.0 mm and the external colour, which might be mistaken for flint, consisted of patches of darker grey (N5) in a paler grey (N7) matrix. When fractured the pebble split easily, without the flashes of flame and dangerous shards associated with splitting the flints, into a pair of parallel transverse and slightly rough cracks of similar colour (N7 and N4). There was a slight hint of greyish orange pink (5YR 7/1) on some parts of the paler fractures, Within the darker grey areas there were paler grey to white spots of 0.06 to 0.08 mm diameter, which were not sand grains, but sections through elongated objects associated with them in random orientations. They are something of a mystery without further investigation, but might be quartz pseudomorphs of the fridymite > 870° C phase of silicon dioxide, if that contact metamorphic texture was not so rare outside the North Ireland to Scotland Tertiary basaltic province. An alternative explanation is that the darker area are of trachytic of Palaeozoic lava containing elongated inclusion of glass and crystals before they cooled down. The host quartzite showed no obvious sand grains and other smaller inclusions except these 10 mm square grey clasts and a few dark 0.06 mm spots of iron oxide.

Quite apart from the different origin and provenance of these smaller pebbles, it is clear that they differ from the associated and generally more widespread flint pebbles (i.e. the latter were also seen along Mill Green Road opposite Hardings Lane and north of Mill House with a 55 mm maximum length) in being rounded and polished into facets by wind blown sand, and not by the rough sand not present around them. Ice is also required to bring them into Essex and it is not required to explain how rounded flint pebbles could be transported from say Reading, as roughly patinated ellipsoids, from the parent Chalk or Paleocene strata by a proto-Thames. However, I suspect that the softer chalk cobble and these polished quartzites actually came from the north by ice and were then polished in a dry but cold climate before being mixed with the rough sand and patinated flints.

2006-07-01T12:32:00.000-05:00

The limited pre-1066 holdings of the Barking Abbey nuns included a manor at Hockley. This was probably where abundant septaria were subsequently used extensively in St. Mary’s Church Hockley. The nuns held a source of these concretions from middle London clay shorelines with fisheries, salt houses etc. at Wigborough and Tollesbury on the Blackwater Estuary, downstream from the River Wid and Chelmsford.

C) Roman and Tudor Bricks at Fryerning. The Roman bricks and tiles were most easily studied in the eastern corner of the Chancel at Fryerning, where the builders had stacked them into a neat pile showing orthogonal, if sometimes obviously fractured dimensions. They were without dark internal reduction bands; unless these were all hidden. A large but fractured specimen had a thickness of 35 mm, a width of 170 mm and a length of at least 255 mm when made. Another had a thickness of 42 mm and equal dimensions of 185 mm on a square plan. According to the book Brick in Essex from the Roman Conquest to the Reformation, written and published by Pat Ryan (Chelmsford, 1996. p.159) the latter dimensions approximate to the Bessalis Roam brick variety (200x200x40 mm); but the larger one might be either a relatively thick tile (normally <35 mm thick) or one of the larger brick varieties (normally 40 to 45mm in thickness). Either way they were all thinner and less regularly placed that the red bricks presumably made at Mill Green and adjacent sites for the small early 16th century tower at the other end of Fryerning Church and the larger one at Ingatestone. Measurements taken at a corner at the Fryerning tower showed dimensions of 235 x116x52 mm, with a repeat distance of the courses of 60 mm which was still less than that seen in more modern brickworks. However, not all red bricks associated with the black and red diaper-work of these early 16th century Essex towers are so thin. The buttresses of Rockford Church tower, built for a patron who died in 1515 show dimensions of the red bricks of 238x117x61 mm and 235x115x60 mm. The showed white sand grog up to 8 mm in diameter added probably to a Pleistocene silt matrix; while the Fryerning Bricks looked relatively fine-grained.

2006-06-27T18:35:00.000-05:00

William and Elizabeth Stone at Ingatestone c.1865.

Enlargement. White gravel "hoggin" path at Mill Green, below the foot of William Stone late 1860's.

June 16 2006. I visited Mill Green by the route of my late Great Uncle William Stone, who lived there while working for the Eastern Counties and later the Great Eastern Railway at their London Terminus, commuting each day and presumably starting with a walk down the hill to Ingatestone Station built in 1846 about 15 years earlier. I was not able to match the doorway of his parents cottage, termed 40 Mill Green in the 1851 census, to the surviving and exposed fronts of buildings facing Mill Green Road and Hardings Lane.
The Flemish bonding of the red bricks made locally by Thomas and Frederick Bangs of the Mill Green Old Kiln is seen on the photograph and local buildings of various 18th and 19th Century ages. The newly named Mill Green cottage on the N.E. corner of Mill Green Road and Hardings Lane had a front path made out of similar bricks and also a wall in which the bricks show dimensions of 220 mm by 110 mm by 65 mm, with a repeat vertical distance inclusive of mortar averaging 81 mm. On the photograph, William Stone
Senior (bapt. October 27, 1816 – April 25, 1870) looks to be 24 courses of these bricks tall, and his wife 22 (Elizabeth Wilkinson (1818-1874) at Margasetting) courses, although the perspective is probably misleading with his height then coming out at six foot four and hers five foot ten!

The usual guideline for laying the usual bricks of Victorian London (thickness 64 to 70 mm) was not more than one foot (305 mm) for four courses, which is less than 76 mm for the repeat distance and simply less than 24/4 feet = six feet for William Stone. At the adjacent Fryerning Church there is a north chapel extension of bricks of about the right age, with dimensions of 215 x 100 x 60 mm exposed on the corner, repeating at 76 mm.

Ingatestone Train station was built in 1846 and shows two types of red bricks, which may of course have been brought in by train. One type is more pink and weathered, with the grog of 21 mm diameter (sand pellets added by the brickmaker) raised and often somewhat grey or white in colour. Examples of this type, measured while waiting for the train (a convenient if unusual pastime) had dimensions of 226 x 116 x 62 mm, repeating at 76 mm and 210 x 115 x 60 mm repeating at 75 mm. The associated old, unreplaced, but less weathered bricks with a darker red colour and finer or absent grog included 195 x 102 x 62 mm, repeating at 73 mm, and 230 x 105 x 61 mm repeating at 71 mm. Even the latter repeat distance would make William Stone, hay dealer of Mill Green, five feet seven inches tall and his wife, five feet one and a half inches. This seems more likely bearing in mind that the top of the door is higher than his head by three more courses. However it is known that their daughter Phoebe Stone used to combine the role of barmaid and bouncer in my great Grandmother’s public house in Stepney in the 1870’s. She also looks to be quite a large lady in wedding photographs.

This visit to Mill Green was also concerned with the gravels, which were seen in the various places and the Norman parts of Fryerning and Ingatestone Churches. It is easier to write immediately about the bricks and walls. It should be noted that the "puddingstone" of these church wall architectural descriptions is iron oxide cemented gravel (ferricrete) and not the silica cemented, Eocene, true Hertfordshire Puddingstone also sometimes seen in Essex churches.

2006-06-27T18:27:00.000-05:00

June 18 2006. a) The Ingatestone. The oldest geological and historical object on display at Ingatestone Church is the yellowish silica cemented sandstone or quartzite, glacial erratic, which has a size and position on the churchyard suitable for assisting people to remount horses there. When A. E. Salter guided the Geologist’s Association to Ingatestone in 1906 (see their proceedings) he claimed that this was a Roman milestone, The Ingatestone, which gave its name to the village. At least two objections can be made despite the existence of the straight Roman Road, now old A12, just west of the churchyard. Romans used cylindrical dressed stone pillars, with inscriptions about emperors and distances cut into them in a suitably civilised manner, not erratics potentially available from Boulder Clay 400 m to the north. Secondly in the Domesday book the manor held by the Saxon nuns of Barking Abbey, which probably contained the church dedicated to St. Edmund and St. Mary, and three adjacent manors which were held by secular Saxons before 1066, were just termed Inga. These other manors probably included Fryerning, where the church is also dedicated to St. Mary, like the Abbey of the Nuns at Barking. St. Edmund was killed in 869 and legends have his body being transported to and from London from Bury St. Edmunds in 1016, presumably along the A12, and rested at the nuns new church at Inga. On the other hand, there is evidence that in 1777 the cross roads forming the nucleus of the village, about 50 yards north of the stone contained the English 23 miles from London stone, which would correspond to the position of the Roman 25 miles from London Stone (their miles being 142 yards less than an English one of 1760, and the baseline or route from London perhaps slightly different). So perhaps this glacial erratic became a less formal marker?

B) London Clay concretions and Barking Abbey. The next historically oldest stories at Ingatestone Church are present in the north wall of the nave, of early Norman age like most of Fryerning Church according to architectural books. Actually these walls look more like the fabric of the late Saxon Paglesham Church and could have been built for the Nuns before Norman windows etc. were put in. Fryerning Church is also dedicated to St. Mary and shows abundant ferricrete Pleistocene gravel blocks, plus Roman bricks and the large isolated flints and other cobbles locally available from the earlier Pleistocene Old Mead deposits. These features are reproduced in Ingatestone Church where I managed to find some additional calcareous claystone fragments, lacking veins, but otherwise resembling the London Clay septaria of eastern Essex church walls. It is difficult to prove that source with glacial deposits so close, but there is no evidence that they are not from the London Clay and had a typical matrix colouration of greyish orange in the Mansell classification, with numerical colours recorded on separate adjacent stones of up to 120 mm length as 10YR 7/4, 10YR7/2, 10YR 7/6 and 10R 6/2. What is significant is that I could not see them in the much larger area of the same fabric of Fryerning; despite looking for them and being familiar with them in the east. True septarian claystones, of a different appearance, probably crop out in the uppermost Claygate Member at Fryerning and would be more common in adjacent lower ground near Ingatestone. However, it s more likely that these stones were probably imported with the ferricrete along the River Wid and Roman Road from Chelmsford.

2006-06-21T12:25:00.000-05:00

June 5 2006. My relatives lived at Mill Green, Essex. The southern edge of Mill Green Common (Essex) is of geological interest in being where Monckton & Herries (Proceedings of the Geologist’s Association volume 11, p.22) discovered casts of univalves (i.e. gastropod shells) in a seven foot section of the Bagshot Formation dug by 1888 below a thinner layer of the extracted gravels. Normally the lower Bagshot Formation is devoid of fossils and this discovery confirmed that it was a marine, nearshore deposit, of similar age to the youngest parts of the London Clay exposed in Essex and Kent. Earlier geological accounts of Mill Green missed these fossils, probably because the pits were not so deep. Since then the relevant area has been made into gardens and woodland. Water for brick making and cottages was provided by a springline at the base of the overlying white micaceous Eocene sands of the Bagshot Formation. The latter crops out on the south side of Mill Green Common east of the cottages built before 1777. The main part of the common to the north of there and to the south of the kiln was occupied by early Pleistocene gravels and reworked Bagshot sands or clays termed the old Head by the geological survey. This yielded a third mineral aiding the cottage development, a form of hard core or road aggregate termed hoggin, composed of white coarse gravel grade flints and a few coarser cobbles (> 64 mm in geological definition) of more angular flint, quartz, quartzite and other stones introduced by an early glaciation of Essex.

2006-06-12T06:59:00.000-05:00

May 16 2006. Returning to the topic of the history of geology raised by the visit to the Prestwich 1853 section at Southend, there are books out on his English contemporary “Charles Darwin, Geologist” (by Sandra Herbert, 2005 in Cornell University Press, Ithaca N.Y.) and “The map that changed the World” made by William Smith in 1801 (by Simon Winchester 2001 Viking Press, 2002 Penguin Books). Sandra Herbert suggests that Darwin was a true geologist but has tended not to be regarded as such because he did not do English stratigraphical work like Prestwich and of course is better known as a biologist and geological thinker. Prestwich is much closer to the concept of a Victorian field geologist inspired by the work of William Smith and making major corrections to his stratigraphy and mapping of south-east England. Smith appears to have had the new idea of correlating rocks by their animal fossil content, particularly ammonites, in the Bath to Yorkshire tract of south-east tilted layers, which he regarded as being deposited on this slope and overlain by loose gravels which he interpreted as Diluvium formed by the Biblical Flood. During the period 1800 to 1807 Smith worked partly on the Norfolk coast and produced a lost work, evidently seen by the first proper geological author on that area Samuel Woodward (see Yorkshire Geological Society Proceedings v.15 p.23 by Dr. L.R. COX). He also set up house in London during this later period and must have encounted the common knowledge that the London Clay rested upon sands and then the chalk in artesian wells then starting to be sunk there. He therefore presumed that the fifty-foot cliffs of stratified glacial deposits of clay at Happisburgh in Norfolk were also London Clay and not the generally thinner and unstratified Diluvium. Glaciation as an origin of these deposits was not fully accepted until after 1840 and taxonomy of ammonites was not exact or confident enough to determine that his subsequently illustrated London Clay ammonite from Happisburgh was the same as those in the Jurassic clay concretions of Yorkshire and had actually been reworked into the later deposit. Meanwhile in the London area, his ideas were taken up by James Sowerby and other gentleman who promptly found additional ammonites from the Yorkshire Jurassic in the London Clay sites of Highgate Hill and Minster Cliffs (opposite Southend) which they more correctly correlated using the nautiloids from the London Clay itself. It is still unclear, at least to me, where these ammonites came from in these southeast England sites lying beyond the subsequently mapped area of Boulder Clay till deposited by the most extensive ice sheets. The Sowerby specimen of Decipia decipiens (originally from the Jurassic Corallian strata) is described as drift Highgate Hill, and his middle has Amaltheus margaritatus (figured as London clay Ammonites acutus) as drift at Minster in the catalogue of Natural History Museum ammonites by D. Phillips (published 1977). Neither locality shows very much in the way of post-Eocene gravels to confuse early investigators with extensive London Clay to look at there. I wonder whether the Minster specimen was not actually ballast in a ship from Yorkshire, which had called at the port of Sheemess near Minster and then sold to tourists. The Highgate specimen could also have been mixed-up by dealers in fossils, or introduced as building stone etc. Certainly there are specimens labelled Highgate in museums, which came from elsewhere. Reading Museum has a very large Yorkshire Jurassic nautiloid concretion dug up recently in the road near Windsor Castle, and on the mapped London Clay, rather than Boulder Clay or gravels. On the other hand, it is evident from even larger stones incorporated into old churches (probably from pagan sites) and smaller ones commonly seen in fields that some Yorkshire or other northern rocks do occur south-east of the officially mapped area of glacial till in Essex. But as noted last week it is far more common to find loose stones that have been moved north by rivers during the ice age from the Cretaceous rocks of Dent where neither of the Sowerby Jurassic ammonites occur insitu. What interested me last week was that even a later skilled investigator like Prestwich had made rather vague notes compared to what I could do in a few minutes on a less clean cliff, with a modern builders tape measure.

2006-06-10T13:32:00.000-05:00

Loligo forbesi adult from fish shop.

2006-06-10T13:30:00.000-05:00

Dorsal view of head and tentacles.

2006-06-10T13:29:00.000-05:00

Dorsal View. Loligo forbesi adult from fish shop reduced by 70% relative to specimen (black) from beach (over two days decay).

2006-06-10T13:24:00.000-05:00

Ventral View. Loligo forbesi adult from fish shop reduced by 70% relative to specimen (black) from beach (over two days decay).

2006-06-07T07:16:00.000-05:00

May 12 2006. Being in doubt about the field identification and to clean the beach with the gulls evidently on strike (or more likely on distant nest sites), I removed the larger of the two squids and determine that it has enrolled triangular fins of Loligo forbesi Steenstrup extending 12 to 60 mm from the posterior apex within a revised estimate of the dorsal mantle = gladius length of 134 mm and unchanged head and arm length of 80 mm. Judging from the paced distance from the breakwater it had moved one metre to the east in three subsequent tides after stranding exactly 2-0 days before being collected. However, it and the adjacent crab, weed etc., suggest that the three later tides had not moved it so far and merely rotated the head round parallel to the mantle as it became more loose. It was determined that one of the two tentacles was actually present as a thin white thread extending to the tip of the much or conspicuous eight arms and had lost the club of sackers. The other one was not positively identified even when the arms were manipulated and it is easy to see that fossil squid with eight arms might have once had two additional different appendages when alive. There had been no rain and much sunshine since it stranded and shrinkage by dehydration had cracked the curved gladius into three parts and reduced the width of the mantle beyond the fins from 30 to 26 mm. The predicted level of the tides were 0.1 m lower for the first one and 0.1 m higher for the other two, but it is possible that they did not do much more than wet the squid which sank like a stone when tested in sea-water. The jellyfish and other squid were not rediscovered but could have been overlooked during a short visit. The other squid probably was alsoLoligo forbesi.

The morphology of this and other cephalopods has been interpreted by analogy with the neutral buoyancy of submarines and the lift plus jet propulsion by analogy with jet fighters. The Elephant in the room in this good work by a now aging generation of English marine biologists in that in statics there is a trade-off between a lack of exact neutral buoyancy and the convenient horizontal posture of these predators, when they are denser than sea-water.

The illustrations show the adult shape of Loligo forbesi from a fish shop and not distorted like those in preservatives reduced by 70% for comparison with the more juvenile specimen shrunk by decay before stranding on May 10 and by drying on the beach fore two days. The lower surface in life (termed ventral) shows the funnel used for jet propulsion with water ejected from the mantle cavity and the upper (dorsal) surface is darker with the skin damaged in the fish shop and not on the beach (the dark colour of the beach specimen is due to the method of making the image but the skin is intact, with spots on the dorsal side and arms, and not on the tentacles or ventral side. The only sign of the two tentacles on the image of the beach specimen are thinner lines at the tip of the arms and in one place near their base, while in the fish shop they are thicker, longer and terminate in clubs bearing suckers. Both specimens showed enrolled triangular fins, which are unrolled in the fish shop specimen with dissection pins.

2006-05-30T18:41:00.000-05:00

May 11 2006. A floatation in aerated sea water experiment on a Cormorant tail feather stranded at Chalkwell on January 3rd reached an interesting event this morning with the water temperature returning to 51° F (10° C). The feather of Phalacrocorax carbo (L.) with a black melanin stained rachis and vane (155 x 18 mm) beyond the white quill or calamus (total length 195 mm) has remained intact and having tilted to roughly 45 degrees from the initial stable angel around ten degrees on May 23, reached the vertical calamus-up orientation today. Some 16 mm of the calamus was above the water. This intact rotation after an additional 147 days in cool sea water contrasts with similarly tested small terrestrial bird feathers which have gone vertical and sunk within 70.2 days (the record held by a predated starling feather of 75 mm length and 15 mm width). Most were nearly submerged when they became vertical. Larger ones disintegrated while floating. Probably the Cormorant feather is adapted to resist decay in sea water and in this respect it resembles both the black and the white parts of gull feathers floated earlier and later, with and without drying. However, the Cormorant feather differs from these gull feathers in having a denser and actually still better articulated vane causing the calamus to initially tilt-up slightly and now to rotate long before the overall density is the same as sea water. Densities are difficult to measure on feathers due to surface tension and instantaneous partial flooding but one can measure the percentage submerged at the tipping point.

2006-05-26T18:28:00.000-05:00

May 10 2006. I intended to continue the geological account of Southend by re-measuring the upper exposed part of the Prestwich or bandstand Pleistocene section. Having done that I found that the 11.48 am B.S.T. tide (of predicted 2.3 m above mean sea-level altitude) had just turned depositing numerous twigs, algae and small crabs as a strandline at Westcliff Shorefield Road. In addition there were jellyfish and two squid deposited just below this line and the limit of wet sand on a sunny day with little wind using the geological equipment it was possible to record the orientation of the squid and the position of these jellyfish. Others were being deposited lower on the beach and seen later at Chalkwell Station; but the exact measurements near the strandline showed that the convex-up jellyfish were not buoyant enough to be deposited higher like the crabs and wood. The public is naturally concerned about jellyfish so I have added notes on that aspect here.

A)Bandstand Cliff section (measured downwards)

100mm of asphalt and bricks added since 1853.

620 mm Brown silty subsoil with flint chips.

230 mm More common flints over erosion surface.

560 mm orange and yellow sands.

750 mm White loam with 5 mm white flint chips.

110 mm maximum thickness of black carbonaceous silt, measured vertically downwards 2.16 and 2.26 metres from the top to the asphalt path and roughly 13 eye-levels of c.1.7 m up from the collapsed path and 10 above the highest London Clay concretion on the eastern slipped face.

710 mm grey marly clay (white calcified to 330 mm)

860 mm orange stained band grading down into similar grey loam.

500 mm more sandy but less clean face with orange loam seen three eye-levels below the carbonaceous band, with reeds about two metres below that.

Specialists in the Pleistocene should and probably have sampled the carbonaceous layer of Prestwich, not for radiocarbon as it is probably too old, but for pollen and other small organisms oxidized in the other beds.

B) Western jellyfish cluster

There were four blue Cyanea lamarcki Peron and Lesueur and one white jellyfish which was probably Aurelia aurita (L.) with an average umbrella width parallel to the strandline of 124 mm (range 85 to 145). The upper edge averaged 1282 mm from the edge of the wet sand (range 830 to 1780 mm) and the lower third of the umbrella was covered by sand on most of them. The spacing of the finds along the strandline averaged nine paces (roughly yards or meters) and there was then a gap of 77 paces including a breakwater of 23 paces to the next more eastern one of 80 mm diameter, 1800 mm from the strandline.

C)Smaller jellyfish

After a further 34 paces there was a cluster of five Cyanea lamarcki and two white jellyfish of 77 mm umbrella width (range 50 to 100), 1104 mm average distance from strandline (range 130 to 1800 mm) and 3.3 pace average spacing. The next breakwater was only ten paces further on and these unburied jellyfish were lined-up by a rip current depositing weed there.

D)Stranded Squid

The most eastern squid was 7 paces beyond the breakwater noted above, with a 120 mm diameter jellyfish being stranded 11 paces down the beach near the breakwater. Flies were already gathering on the squid which had a dorsal mantle length of 145 mm, a total length of 225 mm, a width apparently lacking fins of 30mm, eight arms splayed to a width in the sand of 45 mm and 6 mm diameter eyes. The two tentacles were missing or more contracted than the arms, which extended to 130 mm from the strandline, with the posterior end bent round more parallel to it at 280 mm. The posterior end pointed towards 122 degrees east of magnetic north, compared to 152 degrees on the main part of the body and 102 for the trend of the stranded algae. A second specimen was found 47 paces further to the west where the strandline had the same trend. The posterior end pointed towards 230 degrees and terminated 410 mm from the strandline and the head and tentacles had a trend of 246 degrees and reached to within 260 mm of the strandline. The dorsal mantle length was 135 out of a total length of 170 mm, and showed lateral fins resembling Alloteuthis subulata (Lamarck) situated as triangle well away from the apex. It is possible that the other specimen was its mate; although young Loligo forbesi Steenstrup L. is anther possibility.

E)Another small jellyfish cluster.

Three paces beyond the squid and 67 beyond the last upper beach jellyfish there were eight white jellyfish, probably Aurelia, with diameters averaging 72.5 mm (range 40 to 95) separated from the strandline by 300 to 3100 mm (average 1322) and spaced at average intervals of 4.4 paces. There was then a gap in jellyfish strandings of 93 paces, followed by seven of both colours spaced at an average interval of 42 paces and averaging 656 mm from the strandline (range 110 to 1430). One Cyanea was in a vertical orientation, with the 85 mm diameter rim on the down-current side of a rip current near a breakwater and the whole group had an average diameter of 84 mm.

F)Discussion on jellyfish stings

Including finds from Chalkwell there were 19 measured Cyanea near the strandline with a similar average diameter of 95 mm (range 60 to 175) to the 17 white specimens of 93 mm (range 40 to 150) which may have all been Aurelia. The difference from the perspective of health-risks is that Aurelia has the stinging cells on oral arms buried under the convex-up umbrella and Cyanea has them on thin, very long tentacles, evidently removed from the edge of the umbrella before strandings.

2006-05-21T14:50:00.000-05:00

May 8 2006. I have been reading that the ammonites died out too soon to have died at the end of the Cretaceous defined by the Iridium concentration in the Danish Fish Clay and that the meteorite which hit Mexico was also too soon and merely reworked into that later time-plane (D. Eldred in p. 16-17 of Geoscientist 16 (5) May 2006). A couple of weeks ago I wrote reviews of papers by Marcian Machalski, a Polish Cretaceous ammonite specialist, for a German journal. His conclusion was that a redefinition of the sexually dimorphic subspecies of the ammonite Hoploscaphites constrictus (James Sowerby) produced a final subspecies only known from the shallow-water Grey Chalk in Denmark, some contemporaneous deposits in Poland and the Netherlands and the Cerithium Limestone grading up out of the Danish Fish Clay. This subspecies together with on or more species of the straight ammonite genus Baculites apparently lived after the Mexican impact and also the deposition of iridium plus unusual stable isotopes (M. Machalski, Acta Palaeontologica Polonica v.50 p653-696, 2005). Another of his papers with a Danish geologist Claus Heinberg supported by access to private collections of ammonites previously noted by F. Surlyk and J. M. Neilsen in Bulletin of the Geological Society of Denmark v. 46 p. 115-119 (1999) and appeared in that journal in 2005 (v.52 p.97-111). They make a good case of limestone matrix and microfossils inside the most intact Hoploscaphites being of post Cretaceous earliest Danian age. Since the Cerithium Limestone matrix was similar and graded down via the Fish Clay into both shallow-water and then older deep-water chalk beds, it was concluded that this ammonite was not merely reworked from the Chalk.

Above the Cerithium Limestone is an erosion surface capped by the Bryozoan Limestone and cutting through into the Cretaceous Chalk. The Bryozoan Limestone flints with a paler red-brown colour to the black Chalk flints yielded the probable lower jaw of Hoploscaphites constrictus found as a modern beach pebble by Surlyk and Nielsen (1999). In Poland there is an equivalent occurrence of this calcite part of the ammonites on a early post-Cretaceous (Danian) erosion surface resting on the penultimate and relatively deep-water layer of the Cretaceous Chalk. Neither of these last records of ammonites has to be due to reworking of these calcite plates; but it seems likely when they follow an interval of Chalk erosion this part of the ammonites apparently not preserved with the last Hoploscaphites subspecies. In my view one should use the existing formal Linnean name Pseudostriaptychus portlockli (Sharpe), described from the late Campanian deep-water chalk of Norfolk in England, for these calcite lower jaws of Hoploscaphites contrictus. Perhaps the other post-Cretaceous ammonite Baculites had a similar jaw structure as it did in late Cretaceous specimens reviewed by K. Tanabe and N.H. Landman in 2002 (AbhandlungenGeologischen Bundesanstalt v. 57, p.157-165). The type material is over five million years older than these final undoubted records from the deep-water chalk. But it is useful to have a name for this different type of fossil and to avoid having to write “originally aragonitic shell of” and “calcite lower jaw of” all through the literature on ammonites.

This debate about the last records of ammonites relates to a short period of the geological time-scale although a long one on the time-scale of modern climate cycles and glaciations. Probably it was within one million years five or ten percent of the time between the end of deep-water Chalk deposition and the return of deep-water deposits, with ammonite-like shells related to modern Nautilus (genus Aturoidea vredenburg), at the base of a broadly defined London Clay Formation at Harwich and Walton in Essex.

My previous comments on landslips at Southend omitted the stratigraphy of the local nautiloids discussed in my article in Tertiary Research volume 21, p 39-50 (Leiden 2002). Since that article was written it has become clear that the last record of the Nautilus-like shell Euciphoceras regale (J. Sowerby) does indeed match the sandy MacMurdo Road bed concretions, but that this bed probably lies around 122m up the London Clay in a syncline where the representative of the Wilson Road bed of concretions is at least 130 m above the base and the base of the Claygate Member above that. This type of location and correlation of chance finds is on the same time-scale as the ammonite debate and they are both related to the effect of water depth of habitats and shell preservation. If it is the case that the ammonites were not all killed by the direct effects of the meteorite on plankton etc, then there is no reason why rare specimens could not be found in the London Clay Formation. I have seen what appeared to be a pair of Pseudospinaptychus portlocki plates in a private collection from Butts Cliff in Essex. The specimen needs to be studied morphologically but whatever it was it was local to the London clay level approximating to the base of the cliffs at Southend and being preserved as a pair of plates in a septarian claystone concretion not reworked in from the Chalk in Eocene or modern times. One can collect real Cretaceous ammonites from phosphatic clay and chalky greensand matrices at Southend, and they help to explain why William Smith listed ammonites as index fossils from the London or blue Clay in his pioneer stratigraphic synthesis of England. However, experienced local geologists can solve that kind of distracting problem unlike visitors like William Smith.

Regardless of whether or not this London clay specimen enters the formal fossil record it raises some general issues; not least the need to have a separate formal nomenclature for the separated jaws/operculum of ammonites and nautiloids. One possibility, raised by Zev Lewy in numerous recent papers, is that scaphitid ammonites lost their aragonitic shell and lived on, either as modern naked octopus, or the octopus with a calcite shell (Argonauta). Another possibility is that the giant new and scarce nautili genus Aturoidea developed the ammonite type of jaw when it replaced the ecological position of the extinct ammonites. A third is that ammonites survived as rarely preserved shells.

2006-05-18T07:17:00.000-05:00

Bandstand/Prittlewell Square slip at Southend. This slip was first studied in March 2001 when it showed an intact bandstand above grey silty ‘Ice Age’ deposits and a lower orange band, which I took to be, weathered London Clay. The whole lower half of the cliff had not moved and the slipped area approximated to the width of the bandstand. Finds of septaria could of course have moved down with the slump, or on their own; but appear to have come from ten to 15 m above mean sea-level if unmoved. After the area had been carefully landscaped for the council it collapsed again in the present more conspicuous manner during the winter of 2003/2004. The problem appears to be that the proto-Medway River has cut, or perhaps partly deformed, a north-south valley into the relatively low London Clay with flank elevations capped by gravels still unmoved above 20 m above mean sea-level, and a sequence of porous sediments concentrating rain water over broad front rather than a single spring on the impermeable, but now fractured London Clay surface. The present section was actually recorded in 1853 before landscaping as a cliff half a mile west of Southend (this is correct if he means the pier) shown as a series of horizontal layers in the notebook of Sir Joseph Prestwich housed at the Geological Society in London.

“Clay plus grave” (looks about ten feet)
¾ foot “carb. band” (?=carbonaceous silt)
“10 to 15 feet of sand and gravel (thin gravel layer in the middle of it is horizontal)
“Gravel” (looks about five feet thick)
“London Clay” (shown as grey not orange).

The wave cut platform

For many years the tourist to Southend might be forgiven for not knowing that in the first half of the 19th Century it was regarded as a significant site for collecting minerals and fossils from the London Clay during casual visits. An article in The Gentleman’s Magazine for 1794 praised the resort and included geology in the prospectus of the town then consisting only of the Royal Terrace above the cliffs just west of the Pier and some dwellings along the low lying East Beach. This quotation refers to the western of the two contrasting sites and to the radial needles of the mineral barite (barium sulphate) forming veins with sparry calcite prisms (calcium carbonate) in probably only one or two stratigraphical levels of the calcite cemented clay concretions. Both the cliffs and the wavecut platform extending from the head of the pier to Chalkwell Station consist of London Clay with these concretions in it but they are far less conspicuous and easy to walk about on that on Walton or the Isle of Sheppey beaches. This may because many were removed to make cement in the mid-19th century to make so-called Roman Cement and were not replace due to the slower rate of erosion at Southend. In the 1794 we read that there were:

“numerous round stones hanging from cliffs and dispersed on the shore, stars of different coloured spar, deep yellow to pale straw spotted with coruscent rays.”

2006-05-17T06:46:00.000-05:00

Warwick Road/Casino slip at Southend. The following notes were made on the rotational slump above the Westcliff Casino and south of Warwick Road when it was both freshly formed and helpfully dried-out the autumn of 2001. One can still see the cliff beyond protective fencing and it will probably enlarge towards the west during later flash floods. There are two insitu cliff faces separated by slumped London Clay and all three areas showed a single band of sepatarian calcite (calcium carbonate) concretions with originally pyrite (iron sulphide) smaller nodules between or perhaps just above them. The septaria had a tabular base and a thickness of 0.11 metres, 1.5 m below the ‘Ice Age’ gravels capping the London Clay on the west side featuring a spring lubricating the slump. An equal thickness of clean London Clay was exposed below the septaria on both sides of the area. The London Clay and concretions had evidently been weathered inwards from the cliff face to a pale white or grey colour making them look like drift from a distance and the only later deposits were 0.3 m of brown gravel on the west scar and 1.4 m of finer gravel on the east scar also capped by old bricks etc. The original elevation of the concretion band was determined later by relating it to the undeformed concrete steps on the east side. A spot height on the road above these steps is recorded on the Ordance Survey maps as 31.0 m above mean sea-level, and using a crude level on the steps the concretions were recorded at 23.5 m. Probably 24 m would be a more realistic estimate. Thus although the slip is on one of the highest points on both the cliff top road and the London Clay surface there must still be five metres of porous gravel or other 'ice age' deposits represented by the grassy slope above the slipped face with the spring in it. This water doubtless comes from the old urban hinterland at this depth and bursts out to lubricate the clay fracture planes during flash flooding. There did not seem to be any obvious change in that particular urban environment since the Victorian times when this particular port of the cliff had been made into a stable public garden with trees.

The original pyrite nodules on the eastern scar were in the form of solid red iron oxide (haematite) and on the wetter west side they were decayed to yellow iron and gyspum (calcium sulphate). The primary characteristics of the associated calcite septarian concretions consisted of a relatively fine-grained quartz fabric for concretions in the upper London Clay, with some original carbonaceous laminae largely removed by marine animals in the London Clay sea producing horizontal burrows of up to 8 mm diameter, and smaller polygonal patterns. In thin section there were unusually large trochoidal foraminifera preserved to a diameter of 0.30 mm and a height of 0.18 mm as original calcite shells. They were entirely filled with what had originally been pyrite. There were also solid triangular limonite calcite and rod-like shells of 0.40 mm diameter and crustacean valves of ostracods. A search was then made for other sites in the Southend area showing the same shapes of common microfossils in this fine, largely bioturbated clay matrix. Septaria from the Cliffs Pavilion cliff 400 m to the west and in or around the Bandstand Cliff 400 m to the east had been collected before from up to 20 m above mean sea-level and they were all of a more sandy clay composition, with different or absent microfossils. It was therefore deduced that the Warwick Road cliff was stratigraphically higher as well as merely higher in altitude, despite well record evidence of a steeper dip towards the east along the coast. The highest septaria were probably around 125 m above the base of the London Clay and did not match the sandy highest septaria in the opposite cliffs on the Isle of Sheppey, which may well represent the other Southend levels.

Looking further away there was a small slip on Love Lane, opposite High Mead, near Rayleigh Station, showing the same type of septaria in December 2002. In this case it was wet sand unit within the Eocene London Clay Formation (also termed basal “Claygate Beds” without implying an age difference) which probably supplied water to the steep slope previously produced by the greater stability of more sandy layers of the London Clay. The concretions were however just below this sand and had a relatively fine-grained texture; but with more smaller, less complete pyrite cementation of the foraminifera. They were matched more exactly to loose samples from the A1015 road next to the church at Saffory Close in Eastwood and South Shoebury Common beach.

2006-05-16T18:37:00.000-05:00

May 5 2006. An well-illustrated article for tourists by Laurie Forsyth in the May edition of Essex Magazine (pp. 13-15, Cambridge Newspapers) describes the geology of fossils collected from the beach at Walton-on-the-Naze, derived from the early ‘Ice Age’ Red Crag and Paleocene/Eocene boundary strata of the similarly submarine London Clay Formation. This year tourists to Southend can hardly avoid noticing geological phenomena and they are noted here as additional information to the Essex Magazine account of slumping and the London Clay. However two mistakes need to be rectified. It is stated that the London Clay was deposited forty million years ago and nearer to the equator, resulting in tropical fossils being sunk offshore and now found as stone concretions. Actually if one accepts that the dinosaurs and ammonites became extinct 65 million years ago, then the correct date for the Walton London Clay deposition was 53 or perhaps even 55 million years ago, and not 40 when the whole Earth was just starting to change towards cooler climates and lower sea-levels seen now. One should not be complacent about that trend being reversed, London and Essex were one hundred metres below the waves during London Clay deposition, with the North Sea coast in Dorset. The paleomagnetic evidence for the position of England then would only move it down a little to central France.

2006-05-09T18:38:00.000-05:00

April 17, 2006. The Southend Standard newspaper for the week ending April 7 reports that a four foot long “Dolphin” has been found stranded dead “on a Canvey Beach” six km (4 miles) south west of the Chalkwell Station stranding site noted previously. The date and exact position “near Thorney Bay Caravan Park” (formerly Thorndon Creek) are unclear. This site would normally be considered as ideal for whale watching, with the five fathom channel traversed by the “London Whale” in January situated only 0.3 to 1.0 km south of Deadman’s Point, and becoming as close as 0.15 km – 2 km to the east at the harbour once called World’s End and now Hole Haven. I have never been to Canvey Island and see these delightfully named locations opposite the Dickensian Cooling Marshes. Stranded Cetaceans, like Mute Swans, belong to Queen Elizabeth II in England, and such finds must be reported to the Natural History Museum in London for forensic investigation. If it was four foot long and not yet properly studied then perhaps it was a Harbour/Harbor Porpoise Phocoena phocoena rather than Delphinus delphis growing to twice that length. The average range of the Spring tides present the weekend before the news report increases from Southend to Gravesend as the River Thames Estuary narrows and becomes less saline (particularly when the tide is out). The narrowing occurs mainly at the stranding site where most of the narrow intertidal zone consists of mud below a narrow beach.

Weston Blake (1975 in Geografiska Annaler 57A) postulates that at the arctic locality with a summer tidal range of 3.5 m, the driftwood logs occur on a storm beach 1.5 to 2.0 m above the high tide level and large Bowhead Wales Baaena mysticetus with a body thickness of four or five metres around the low water mark. He cites a remark by V. Stefansson (1921, The Friendly Arctic MacMillan, New York 784 pp.) as the main observation about these whales.

“We know through observation of many stranded whales that their skeletons always lodge not at the upper level of wave action, as is the case with driftwood, but at the level of the low tide or even lower.”

This rule suggest that in parts of the English coast with a great tidal range even large whales will be conspicuously stranded for study and elsewhere in microtidal environments they will be eaten by fish and go generally unobserved. What mattes is not so much the length of the cetacean but the thickness of the body below the waterline and any tendency for the body to have the same density as the surrounding water. In that state of neutral buoyancy the greater density of the jaws will produce a head-down posture stranding the corpse, or at least damaging it at depths equal to the whole body length. Bowhead whales have much fat around a large jaw and overall buoyancy, but some of the smaller cetaceans like porpoises may pass through a phase of neutral buoyancy as decomposition gases develop in an initially denser body.

The Leigh and Westcliff Times for the week ending March 14 2006 reported another (or perhaps the same) Porpoise. It was stranded on the Leigh foreshore until "the tide swept the body back out to sea again."

2006-05-07T11:43:00.000-05:00

April 16, 2006. A large Maritime Pine tree (Pinus pinaster) was seen in flower today, with bright yellow flowers looking like old-fashioned Christmas tree candles at Easter. The large brown cones are much less conspicuous and overlooked before since they disintegrate on the tree. A search for cones and other parts of the species was made below other trees on April 10 and yielded a whole flower blown down on a twig bearing a cluster of needles, which has remained floating in sea water since that date. But the cones were only present on the ground as darker brown older versions of the picked cone discussed on April 7, which had split into quarter segments and had additional cracks extending in the same axial splitting direction through the scales. In this respect these mature cone fragments resemble the stranded cone found that day, and they also resemble it in lacking the spines seen on the middle of the scales of the picked juvenile cones. However, the Maritime Pine Cones do appear to be grown eccentrically on their attached twigs on trees than the stranded cone. Another indication of Spring at Easter this year is the Hawthorne (Crataegus monogyna Jacquin) leaves just opening and the similar-looking hedges of Blackthorn (Prunus spinosa L., it is a type of Plum) with the white flowers out since at least April 10. The old Essex term for this blackthorn hedges row in full bloom was “snow in springtime”. According to the books both Hawthorne and the Maritime Pine are not due to be in flower until May, but the latter is clearly well ahead. The dry and cold winter supplied brown oak leaves to the beaches after rain on April 9/10.

2006-05-01T18:44:00.000-05:00

April 10 2006. In a thought experiment about the recently floated large pin cones, I wondered whether the closure of previously dry scales on the tree, ground or upper beach will trap indications of their source when stranded or sunk in the sea. On the 8th I collected two smaller cones of Pinus nigra Arnold from the grass, which was dry enough for the scales to be open. I floated them in a box of sea-water containing reed stem fragments not yet sunk after being collected from the strandline and refloated a day later on March 26. As expected the scales have now closed trapping about 20 of the mm diameter stems largely in a roughly axial orientation and one plane, but with a few held transverse to the cone or hanging below the water line.

Last night it rained and so I revisited the same tree at sunrise before the scales could dry. It was disconcerting to find an adult starling lying with contracted legs and open bill dead on the pavement (American sidewalk). I buried it in the garden as probably the best response with Scottish bird flu still in the papers. It is unclear whether it would have seen the light of day again before entering a landfill site if placed in the black garbage sacks being collected early this morning.

The pine tree showed all of the scales on previously fallen cones now closed and a few fallen on to the pavement were slightly open. Five were collected and floated in sea-water, three being clean, one showed winged seeds projecting out of the scales and one had two paired pine needles (50x80 mm long). They were firmly held transverse to the cone axis on the lower plane near the grass. One of them had degraded when on the grass during a relatively dry winter with little frost into the same texture of blocky split scales and projecting originally internal spines seen on the cone stranded at Chalkwell last week. In that case the fibres were rather like the claws of a cat and in P. nigra they are evidently more straight and softer. In both cases these more degraded types of cone did not close tightly enough to trap pine needles and may have lost their seeds while still on the tree.

In looking at the two large cones floating in sea-water one can see that where the picked one contained thin winged seeds (near the base) the closure of the scales has produced tight sutures, but elsewhere there is much space and distortion between them. The previously drifted cone contains some marine debris between these wide spaces between the scales but it is not tightly held like reeds adjacent to a cone which fell into the sea. Illustrations of cones from the Dutch coast (as drawings, which may have omitted damaged areas) show none of the axial cracking of the scales and exposure of their internal fibrous structure seen on the drifted cone from Chalkwell. Damage from being stranded by a rough sea, or even being in the open North Sea for weeks, is therefore unlikely to explain the poor preservation of the scales. It is less easy to exclude damage from grey squirrels and general decay while these larger types of pinecones are still on the tree as a possible cause. If the Chalkwell Cone is from a Knobcone Pine then someone living from California to Oregon could investigate the stages of disintegration on and below the trees in their own habitat. If these deductions are correct then it is unlikely that the Chalkwell cone was imported from there as an impressive dried ornament thrown into the Thames recently. A botanist (not me) might be able to formally determine the species and where it grows as introduced specimens in Europe. However, botanists, like squirrels, tend to dissect cones, and it would be nice to see how long it floats for compared to the similar sized picked cone and the dry or wet smaller fallen cones.

2006-04-26T18:48:00.000-05:00

(April 7 2006 continued....)Since the Southend cone came from a small tree with 90 mm long needles in pairs within each cluster on a twig it was relatively easy to identify the cone as the Maritime Pine Pinus pinaster Aiton. The Chalkwell cone resembled the scales of the Stone Pine Pinus pinea L. but in stranded material from the Netherlands side of the North Sea the cone length varied from 80 to 150 mm at a much greater diameter of 100 mm (C.J.E. Brochard, G.C. Cadée 2005, Tropische drijfzaden van de Nederlandse kust, in Tabellensie Strandwerkgemeenschap no. 30). The Kriobcone Pine Pinus attenuata Lemmon with a length of 140 mm at Texel and 130 mm at Schiermonnikoog is a better match in general shape except for the Kriobs which could perhaps have become worn or lost at Chalkwell. It would be instructive to see which species were being sold in England and Canada as ornaments last Christmas and how long these two cones will float.

2006-04-25T06:49:00.000-05:00

April 7 2006. The tidal cycle of 14 days first described by a stranding of cuttlebones low on the Southend-on-Sea beaches on March 24 is now repeated by the morning predicted tide at 1.6 m above mean sea-level (O.D) surveyed as a largely algal strandline for 1.8 km east of Chalkwell Station, 0.8 km at Shoebury East Beach and 4.2 km from South Shoebury to Southend Pier. The only new find of a cuttlebone was on the old highest strandline at the East Beach, measured as actually only 1.5 m above the latest strandline using the top of the anti-E-Boat Boom as a horizontal datum. This cuttlebone with an intact width of 35 mm and broken at both ends was probably stranded 14 days before and moved to the higher point on the same or an adjacent beach over the next seven days. After that it was presumably hidden from my surveys by algae since decayed and dry enough to be winnowed by the generally westerly winds there. The new strandline is one of four to eight seen on various parts of the beaches and like them is largely composed of brown algae, a few reeds, whelk egg cases and an offshore ridge of flint gravel or bivalve shells. Abundant reeds are largely concentrated in the two highest strandlines and one in the middle, and confined to the south-facing coast.

Two new finds made today were a spiny spider crab (Maja squinado) with intact legs joined to an entirely predated dorsal carapace and body (eastern Southend) and a pine cone on the same lowest strandline at Chalkwell Shelter with the axis parallel to the shore. It was larger than the usual pinecones seen growing locally, except for one near Southend Pier. Having obtained a cone from there and let it contract in width from 80 to 51 mm in sea-water, it became clear that it was not the source.


Characteristics                   Chalkwell         Southend
Length                            130 mm            105 mm
Diameter (from circumference)      59 mm             51 mm
Dia. of attachment stalk           12 mm              8 mm
Cone axis to stalk axis             0 mm             10 mm
Largest width of scales            21 mm             16 mm
Axial scale dimension         less than 11      less than 11
scale number of sides               4                 6
central umbo                      flat             spine
colour                           dark           pale brown
features                axial split scales   scales intact

2006-04-24T14:26:00.000-05:00

April 3 2006. The beach walk was repeated during and after the quarter to five pm (British summer Time) tide of 2.5 m O.D. predicted altitude. At Shoebury East Beach, as elsewhere, the tides over the weekend had added another gravel ridge capped by a reed-dominated strandline, below the previously examined one with cuttlebones (three more being found there, but not elsewhere where the reeds still resemble piles of hay in most places). The new and relatively sparse strandline was formed by waves breaking during a gentle, warm, dry westerly breeze, producing a large human population by sunset and stranding partly eaten apples and cucumbers slices. More generally there were reeds which had been out of the marsh for some days; being smaller and bound together by more common brown algae like those ’floral tributes’ seen by the roadside after accidents. Driftwood and leaves were more common, or at least more conspicuous, than before. Probably the leaves were washed into the sea the day before when the westerly rain squalls had roughly coincided with the relatively low predicted tide around 4 p.m. That rain may have also helped to cut the two reed bands into a vertical sand cliff near Lynton Road in Thorpe Bay. The base of it was far above the level of the new strandline there. The only place where fresh, unbound and larger reed debris were present in this new lower strandline was about 1.0 km east of Chalkwell Station (near the Westcliff Toilets). To the west of that spot the new strandline was hardly visible at all. In the east, half a coconut was stranded like a boat in Thorpe Bay (below Tyrone Road) and spinose Echinocardium were seen again in South Shoebury.

An interesting find was of a sliced but otherwise intact coconut stranded concave-up like a boat on the sand of the new strandline in Thorpe Bay below Tyrone road. It could not have been broken on the seawall there, as even the two old hayfield strandlines did not reach it. It also could not have come far before enough water would have entered the concavity of the white and locally bird-pecked endosperm flesh to sink it. In a static subsequent test it sank within four hours by water leaking around the edge of the fractured nut wall and straight away in the concave down orientation likely to be soon produced by waves today. I have seen coconuts floating like boats before at Southend and imagine that they sink on to the mudflats soon after being split on impact with the sea wall pier, or breakwaters. Then having been pecked at for one tidal cycle they can come back in as hemispherical boats to strand.

I use to think that local humans put them into the sea at Southend during picnics, but this is unlikely since they would presumably then eat at least part of the endosperm flesh having gone to the trouble of breaking the top off (which is not easy unless you go to the seaside with a machete and so run the risk of arrest on the train’s new detectors for weapons etc.). It is true that both half-eaten apples and slice cucumber were on the new strandline, but that is more easily understood as overfeeding in lunch boxes. Probably the coconuts are put into the sea as part of Hindu rituals, perhaps in London canals far away? It would be interesting to relate their dispersal to particular dates and modes of preservation when they start their journey .

2006-04-24T14:25:00.000-05:00

Looking south east to the Crowstone. Chalkwell Beach view south east jan 26 1963.

2006-04-24T14:24:00.000-05:00

Leigh-on-Sea Jan 26 1963.

2006-04-24T14:23:00.000-05:00

Looking foward to Canvey Island from Chalkwell to Leigh shoreline 26 Jan 63.

2006-04-24T14:22:00.000-05:00

Looking west to Chalkwell Station 26 Jan 1963

2006-04-24T14:21:00.000-05:00

Leigh Marsh with Canvey Island beyond (1960) with Cooling Marsh in the mist beyond.

2006-04-23T09:06:00.001-05:00

April 2 2006. On going to Chalkwell Beach this morning at low tide the water in the paddling pool was warm and proved to be 50°F (10°C) to disprove my earlier remarks about not bathing there. This winter the snow has melted above the water level there. The sampled water was not below 37°F (2°C), but ice has build up at that spot in colder years in a similar way to the reeds now shifted up the beach by several high tides since my last observation of it spread on the now clean lower sands. Quite recently (?Jan 1991), I noticed a Canadian-style ice-float above the tide mark cementing the sands there. A set of photographs taken west looking towards Chalkwell station, out towards ice rafts coming from Canvey Island, the Crowstone to the east and of boats at Old Leigh, show the sea nicely frozen on the morning of 26 January 1963. My father took them on a morning described as a thaw in my diary, when the tide due about 13:10 hours G.M.T. had not been so high for 14 days. One can see the height at the time the photographs were taken from the ice flows around the inscription plate on the Crowstone, to be lower than at that high tide.

Today the most interesting find was a intact, buoyant coconut with one 'eye' missing to expose a hole through the underlying endosperm produced either by decay in the sea, or during the Hindu ritual? It was below the strandline at the usual spot for stranded birds at the station, perhaps because it had rolled back with the tide or been kicked there. A husk of coir, almost certainly of the same coconut was in the latest strandline of reeds about 100 m to the east (beyond one breakwater). A Breast Cancer Charity walk to the Halfway House and back (from Leigh Station) was going on. It was hopefully over before heavy rain arrived in the west wind at 3 p.m.

2006-04-23T09:06:00.000-05:00

2006-04-21T13:01:00.000-05:00

(March 29, 2006 continued...) This extended to Leigh at around 1.5 m O.D., where the main evidence of the actual strandline was an older pile of reeds nearly at the road level in the protected gulley on the east side of Bell Wharf. These older reeds were virtually absent from the high beach gravels between Lynton Road and Southend Pier and concentrated on the west side of the Casino and various breakwaters at South Shoebury. It would seem likely that the reeds come from the northern marshland around Canvey Island when the tide is high enough and that they cannot reach even the adjacent Leigh to Chalkwell station beach before the tide has ebbed for several hours. Presumably during the next tide, of any level, they will shift eastwards to Shoebury, particularly if the wind was from the south and west as it was on March 29 and the day before. Reeds float well but the bitten cuttlebones refloated in seawater on March 24 had sunk by 22:00 hrs GMT on March 30.

There were only two finds of new cuttlebones on the March 29 strandline-one on Shoebury East Beach where the wind was blowing parallel to the beach and one just east of Warwick Road, about 250 m west of the previous Lynton Road find in Thorpe Bay. This was roughly where the reeds start to thin out westwards on March 29 and eastwards on March 24. Using a compass, which I had taken this time since I expected that cuttlebones might be seen, one could determine that the narrower (posterior) end of the dorsal-up shell was pointing 155° east of magnetic north (S.S.E.) where the reeds and brown algae defined a strandline trending 110° east of magnetic north (true north is about 2 degrees east of magnetic north locally at present). The shell had a width of 29 mm and a preserved length of 55 mm and the one from Shoebury 42 mm and 82 mm.

2006-04-20T06:40:00.000-05:00

(March 29, 2006 continued….) In summer it is more difficult to trace a strandline since there is a tendency for people to sit on it during dry weather when such surveys are easier to do. I did the whole route on June 21 2002 when a national sporting contest cleared the more crowded areas of the beach around Southend. In that case the predicted tidal level was 2.4 m O.D. and the most interesting finds were spinose sea-urchins of the genus Echinocardium and a non-spinose regular sea-urchin Psammechinus miliaris (latter stranded intact near Half Way House public house and found to float for 2.4 days when kept in seawater since it was discovered there). Echinocardium with some spines attached and so freshly stranded that they attracted the interest of flies where found today (March 29) tossed on the reeds above a gravel ridge cut by the tide along the open South Shoebury Common coastline. This also featured a cabin cruiser stranded parallel to and just below the new cliff of gravel, and a less intact smaller boat thrown with piles of the reeds under beach huts at Thorpe Bay. The reeds had evidently been transported to this area by the south and west breeze which had persisted since the last visit in which this area was devoid of reeds at all levels of the beach. Elsewhere one can imagine that the reeds had merely been reworked from the lower strandlines as the tide rose through the week, cleaning the lower sands of all their buoyant materials. However, on returning to Chalkwell Station with the tide now gone far out and the sun still not set, there was a new spread of green reeds, plastic bottles and the usual new dead bird on the lower part of the beach bordering on the mudflats.

2006-04-19T13:37:00.000-05:00

(March 29, 2006 continued...) The survey of one strandline from Shoebury to Leigh done on March 24 was therefore repeated, starting at Chalkwell Station with a wild grey tide just on the ebb around 2 p.m. British Summer Time near the predicted height 3.3 m above mean sea-level (Ordnance Datum). The studied March 24 tide had a predicted altitude of 1.6 m O.D. and the next one which permitted the strandline to be studied was only predicted to reach 1.4 m O.D. Tides are highest, in terms of astronomical predictions but not weather conditions, around the Spring Equinox on March 20 and the other equinox on September 23 this year. But the highest predicted tides do not occur exactly on these dates being likely to occur one day after the full moon and one-hour after the true (not British Summer Time) midday or midnight at Southend.

2006-04-18T14:50:00.000-05:00

March 29, 2006. Charles Dickens, writing in 1860 from his home at Gad’s Hill in Kent, 12 miles (21 km) south-west of Westcliff, gives a description of Cooling Churchyard and Marshes situated half way between them on a winter’s day (Great Expectation p.2):

“The dark flat wilderness beyond the churchyard, intersected with dykes and mounds and gates, with scattered cattle feeding on it, was the marshes; and the low leaden line beyond was the river; and that the distant savage lair from which the wind was rushing, was the sea.”

On can see Cooling Church from Westcliff in Southend-on-Sea, both on a nice sunny day and on that kind of windy day in which the rain showers look like black holes in the universe heading over to Kent. It is only the poor inhabitants of Kent who cannot bask in the sun on their Thames Estuary and look north. But the wind is more usually coming from Coolings in the southwest. It is not actually warm when full of rain but does at least clear away to show either the church or a romantic illusion of open sea or infinite mud flats hidden in sea fog. Today the wind is blowing from a clearly seen Cooling Church. The tide is predicted to be among the highest in the year and with little or no rain or fog about. It is a good time to repeat the walk of March 14. Just don’t go in the coldest sea-water around the U.K.

2006-04-15T06:37:00.000-05:00

(March 28,2006 continued....) Returning to the topic of trees in this context it is no longer possible to imagine how dark King's Hill would be before dawn and light pollution. Judging from experience elsewhere it is not particularly difficult to move over open country at night, but movement under a deciduous wood, before the leaf fall in September and without lights is another matter. One therefore wonders whether the Wednesday after St. Micheal's and all Angels Feast correlates with moonlight; but that is not the case now and how the Roman calendar worked. One can imagine people assembling the evening before the court from their wooded manors and later going through some sort of parade in a relatively open spot shortly before dawn when one can see to move about and write charcoal notes.

2006-04-14T14:14:00.000-05:00

(March 28,2006 continued....) There is a similar local Latin text reproduced with a translation by Phillip Benton in his History of the Rochford Hundred (1867-1888). This relates to a ritual which used to take place on the sandy hill on the north side of the cutting of the AL27 road in Rayleigh, which in this earlier period would have been a good site for a King based in Prittlewell to gather defense forces from the hundred against an attack at dawn from the Welsh in London. Later on it was doubtless used to gather work force obligations for the construction of Rayleigh Park pale and other such local projects. The ritual took place on the first Wednesday, or perhaps originally Wooden's Day, after Michealsmas (perhaps once the equinox?) at dawn on this King's Hill at Rayleigh. The Latin text is:

Curia de Domino, Rege,
Dicta Sine Lege,
Tenta est ibidem,
Per ejusdem consuetudinem,
Ante ortum solis,
Luceat nisi polus
Senescallus solus
Nilscribit nisi colis
Toties volucrit
Gallus ut cantaverit
Per cujus soli sonitus (or solum sonitum)
Curia est summonita
Clamat clam pro Reye
In Curia Sine Lege
Est nisi cito venerint
Citius poenituerint
Est nisi clam accedant
Curia non attendat
Qui venerit cum lumine
Errat in regimine
Et dum sunt sine lumine
Capti sunt in crimine
Curia sine cura
Jurati de injuria.

"Apparently this says that a court of the Lord the King termed
Sine Lege, or a court of Baron, was held before dawn and that after the cocks crows the steward writes with charcoal and cries secretly for the King. The people (who presumably were asked to make obligations) at the court were instructed to arrive quickly and without lights or be held in contempt of court. One can imagine that lights on Kings Hill would be seen for miles before dawn, and then with the sunrise the King would see far into the west from there.

2006-04-13T18:50:00.000-05:00

(March 28, 2006 continued....) The name Camp Bling is explained by a notice posted by the protestors on an area of grass taped-off as the site of the Saxon graves excavated in the winter of 2003-4 by the British Museum. Apparently the popular press reported the small early Christian gold ornament and rather more impressive blue glass Aylesford Ware pot as the grave goods of a “king of Bling”. The existence of a coin from the Merogovians on the continent supports the dating to the time in the first half of the 7th century when the East Saxons were converted to Christianity twice, before finally being reconverted after the bad omen of the plague by Wilfred (see above). What must be the oldest recorded English conversation in London is recorded in all the history books and may now be seen to relate to the death of the first Christian king at Prittlewell and the arrival of his unbaptised and aggressive sons at St. Paul’s Cathedral within their inheritance. “Give us that white bread you gave to our father Saba”. This sounds like a more likely conversation than the one about Pope Gregory dispatching the missionaries to Kent by Rhymes in a Roman Slave Market.

2006-04-10T13:40:00.000-05:00

March 28 2006. Visit Sutton Cemetery to check some family history dates and pass near Prittle Brook several tree houses and associated tents termed "Camp Bling" by the people who have lived there through the winter protesting against a road widening plan destructive to mature trees. Less attention has been given to the destruction of trees along both railways to Southend to prevent leaves falling on the line and causing delays to trains. One wonders whether this will work unless large tracts of the woodland outside the railway company fences are removed as well, with the now removed smaller bushes no longer trapping the more distantly blown leaves. Much will depend on the prevailing southwest wind direction during the autumn rainstorms, and the type of trees (which stagger their leaf fall until January in many oaks) and whether the track is on an embankment or not. The distance which leaves move by normal winds, normally only to the east (along many tracks) or northeast, depends on the height of the tree and is roughly ten times the height of trees, which are often 30 m high and with bases above the tracks in woodland surviving on Essex sandy hills.

2006-03-31T10:32:00.000-05:00

(March 24 2006 continued...) Probably the Whiteweed was torn off the sea floor near Southend Pier and moved eastwards with the wind and tidal current, while the Hornwrack and cuttlebones had come from the open sea and sandbars. What was interesting to notice was that the cuttlebone only appeared where the reeds had stranded and then only in a few places protected in some way from the main current. Those at Westcliff were rather downstream from a projection on the promenade and near where the coast bends back slightly to the north. One from the east side of Bell Wharf in Leigh was at the end of a current along Leigh Creek which could not extend far beyond that point during so low a high tide. Another cuttlebone came from just east of Lynton Road near Thorpe Bay, where the beach turns slightly to face the strong current preventing stranding at South Shoebury and is somewhat more protectected by breakwaters than to the east. Two more were found at the end of this second barren zone. One caught with reeds under the Corporation Pier (not the famous Southend Pier now much obstructed with a fence and barren inside it) and a second on the lee side where the East beach turns slightly to the north again. Two more were found where the East Beach debris normally strands; on the last patch of sand before the amusement park juts out as a projecting barrier of stone. The total number of cuttlebones present in a surveyed strandline of 9.2 km length and a meter of 50 width was therefore 18. Their average shell width was 32 mm (range 23 mm at Leigh to 42 mm at Shoebury, with all anterior ends and all but two posterior ends broken-off). Shells of this size are juveniles of the first winter. It is possible to do a more refined study of second year specimens by counting the chambers added after the narrow winter chambers.

2006-03-28T07:53:00.000-05:00

(March 24 2006 continued...) Following the same method that beach yielded ten more cuttlebones from the latest strandline with reeds and an injured gull on it. A dead gull was present with them at Westcliff in December 11, probably onshore storms winds with rain has the same adverse effects on gulls at it does on us. Walking back on the more south-facing part of the same strandline from the coastguard station at Shoeburyness to Bell Wharf at Leigh, one could see a change in the associated biota from bivalve shells in the east (where not even algae were deposited, let alone more buoyant reeds and cuttlebones), to Hornwrack around eastern Southend, to Whiteweed at Leigh. Whiteweed is actually an animal hydroid colony which is termed Sertularia and like the Hornwrack (which is another animal colony, made of bryozoa termed Flustra) sinks in one or two days in sea-water when taken home.

Sepia officinalis shells stranded

2006-03-27T11:18:00.000-05:00

March 24 2006

The cold weather ended during the day started by rain with a wind from the east-south-east, contemporaneous with a relatively low high tide at around 6 a.m. G.M.T. On visiting Westcliff beach shortly before noon, the latest of many strandlines of brown algae and gravel ridges was seen to have the additional components of reed debris, whelk egg cases and two small cuttlebones (the same shells used by owners of caged birds, but in this case small specimens of the English species Sepia officinalis L. with marks matching the bills of fulmars (Fulmarus glacialis) made far out to sea. This pair of shells were at the same spot below Holland Road in Westcliff, where two were found in December 11 2003 and encouraged me to take the train and collect 50 more from the more exposed East Beach in Shoebury.

"Bird Flu"

2006-03-26T15:16:00.000-05:00

March 17, 2006

Part of Chalkwell beach next to the train station is cordoned-off with people in protective clothing looking at it; presumably because a bird corpse had been stranded there in the same spot as the pheasant wing in January. It is just as well that I made my bird feather collection before this bird influenza scare got properly started. It is not a new phenomenon. The Anglo-Saxon Chronicle of 671 C.E. reports "here was a great mortality of birds (producing) a foul stench over both land and sea from the corpses of small and large birds." That was five years after 'a great plague of men' caused the Essex missionary Cedd to die at Lastingham Abbey and the East Saxons to revert to paganism until reconverted by Wilfred. Perhaps the disease had mutated from us to birds in a reversal of the pattern feared at present.(I read later in the paper that they were actually removing graffiti.)