Tuesday, May 30, 2006

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.

Friday, May 26, 2006

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.

Sunday, May 21, 2006

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.

Thursday, May 18, 2006

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.”

Wednesday, May 17, 2006

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.

Tuesday, May 16, 2006

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.

Tuesday, May 09, 2006

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."

Sunday, May 07, 2006

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.

Monday, May 01, 2006

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.