Fossil Hunt at Isle of Sheppey, 12th Nov 2017

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On Sunday 12th November UKAFH met in Warden, a small town on the Isle of Sheppey in Kent for the last UKAFH fossil hunt of the year.

Along the East coast of Sheppey is the largest exposure of London clay in the UK stretching over 6km from Warden to Minster on Sea. The London clay is a marine deposit roughly 52 million years old at this location, of the Eocene epoch. The fine sediment was deposited in a fairly deep, warm and placid sea which was relatively close to land – evident in the abundance of wood and plant remains and occasional but rarely terrestrial birds, mammals and reptiles.

After a fantastic explanation of the local geology and palaeontology by Sam Caethoven and a show and tell of some exceptional specimens by Eliott Mills, we were off in search of fossils!

We were bombarded by a strong, bitterly cold arctic wind but fortunately it was not long before we made some great finds. Lucy was first off the mark with a beautiful shark vertebra, found just a few hundred yards from the carpark. Gastropods, bivalves, nipa fruit and shark teeth were all found within a short time on the beach. We soon headed further north along the beach, staying clear of the tall clay cliffs which are particularly dangerous at the moment as large clay blocks are falling frequently – The site is prone to extreme erosion, most evident by the world war two pill boxes which once sat atop the cliffs but are now haphazardly strewn on the beach in front of us. Beyond the pill boxes, the great finds just kept coming. Numerous crab specimens in phosphatic nodules were collected, some of which were exquisitely well preserved. Shark teeth, ray teeth and fish vertebra were also abundant. Eliott Mills made the exceptionally rare discovery of a leaf preserved in clay.

The relentless biting winds made hunting tough, but we endured and were rewarded for our hardy nature. Thank you to everyone who attended, it was a great day and I hope you all thoroughly enjoyed yourselves!

See you all again in the New Year!!

UKAFH weekender at Folkestone and Samphire Hoe, Kent 14th and 15th October 2017

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The Folkestone foreshore

On Saturday 14th October UKAFH took a group out to the Warren, Folkestone for day one of the Kent weekender.  We were blessed with unseasonably warm weather as our group of 30 descended the (pleasantly dry) mud footpath down to the beach to begin our hunt through the Cretaceous period! Once on the beach, UKAFH leader Chris Tait briefed the group on the geology of the location and what we might expect to find.

The rocks at Folkestone represent the Albian stage of the lower Cretaceous, 110-105 mya.  Lower Greensand is found at the base of the cliff with Lower and Upper Gault clay resting conformably atop, however the clay slumps over the Lower Greensand and is eroded at sea level to release large volumes of fossils onto the beach in this highly productive locality for fossil hunting.  During the time these sediments were laid down the UK was at a more southerly latitude in the area of the modern day Mediterranean and a warm sea teeming with life covered the UK.  During this time sea levels were transgressing, with the Lower Greensand being deposited as and continued to erode, to be replaced with fine clay sediments once nearby land was completely submerged.

The Lower Greensand is less fossiliferous as the near-shore environment it represents was less suitable as a habitat but still contains excellent fossils such as ammonites; the Gault Clay, however, is packed with diverse fossils, some with exceptional preservation. Ammonites, belemnites and molluscs are common; nautilus, crabs, crinoids, fish remains, shark teeth and scaphopods can be found, along with rare finds of reptilia. Examples of all of these were found by members of our hunt group!

Phosphatised preservation is typical but quality is variable, with examples often fragmented or in nodules.  However many examples are preserved in superb detail in pyrite and those which are newly emerged from the clay can retain some or all of their nacrous shell.  Bivalves and molluscs which are newly exposed are often extremely fragile and are rarely collectable unless carefully removed along with the surrounding clay, but ammonites are more durable and make marvellous specimens to add to a collection.

Soon after we reached the beach heading towards Copt Point the finds were already plentiful.  Partial regular and heteromorph (partially uncoiled) ammonites and bivalves were quite common and finds increased as people “got their eye in”. Some of the group progressed quite quickly along the beach to inspect the slips of clay for freshly washed out fossils and check out the shingle between the large rocks and boulders on the foreshore. Others remained nearer the start of the beach, working methodically through the shingle by hand, with a trowel, or dry sieving, in search of smaller finds like shark teeth.

Several members of the group found shark teeth, with Isabelle finding the largest example.  At the other end of the scale, Sam found a small but scarce Acrodus shark tooth while sieving using a 3mm mesh. Sieving is a good technique to remove sand and search for small fossils which wash out higher up the beach because they are lighter. Sieving and shingle-searching up the beach yielded crabs, solitary corals, urchin spines, shark teeth and vertebrae as well as fish teeth, a turtle bone and the day’s star find, a swordfish tooth!

By the end of the day we had a really great selection of finds amongst the group!

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Leader Selfie

The following day we were greeted with yet another gloriously sunny autumn day, enhanced by the towering white cliffs of Dover above our meeting point as Samphire Hoe Country Park.  We had another full house of attendees and headed west along the beach to hunt for fossils amongst the chalk boulders on the foreshore.  Aidan Philpott, UKAFH Leader, explained the geology and identified local fossils to look for to the group. The lower chalk (also known as the grey chalk) at Samphire Hoe is from the Cenomanian stage of the Upper Cretaceous so yields fossils aged 100.5 – 93.9 Mya.

Common finds are brachiopods, bivalves and echinoids. Sponges, shark teeth, worm tubes, gastropods and fish can also be found and, rarely, ammonites. As well as beautifully preserved fossils within the chalk, some echinoids and shells and many sponges form flint casts which can be washed out of the chalk and found in the shingle.  Attractive pyrite crystals can also be found in the chalk.

Our first find of the lay was an eroded echinoid inside a flint block.  UKAFH leader Chris Tait then found a large section of clam.  These giant molluscs are mostly found broken into small pieces so this was a really nice find.  As the day progressed a good variety of finds were made including echinoids, shark teeth and brachipods.

Samphire Hoe isn’t the easiest location for fossil hunting as you need to scrutinise the loose chalk boulders on the foreshore carefully for signs of fossils and then extract them very carefully with a chisel to ensure they are not damaged.  You can also hammer the boulders to break the chalk up in search of fossils so work, tools and care are needed to have a good chance of finding fossils here.  Once extracted, however, preservation is usually excellent, with fine details clearly visible.

Cleaning chalk fossils is easy, requiring little more than dry brushing the remaining chalk matrix with a soft brush (a children’s toothbrush is ideal) to remove any chalk remaining on the fossil surface.  As chalk is very soft, you can easily remove larger amounts of remaining chalk with a blunt knife or craft knife until you approach the surface of the fossil and switch to brushing.

Finds were pleasing but not abundant, however everyone enjoyed the hunt and the sunshine day.

Chris, Aidan and Sam, your UKAFH leaders, would like to thank all of our members and attendees for joining us on our weekend fossil extravaganza and we look forward to seeing you all soon!

Click here for our UKAFH news and to see out upcoming events (we update the list regularly so check back often!)

https://ukafh.com/events/

 

 

Fossil Hunt at Seaford 1st October 2017

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On Sunday 1st October, UKAFH ventured along the coastline of Seaford in East Sussex – a small town about 10 miles east of Brighton with towering white cliffs.

After a very fortunate summer meteorologically speaking, we had spent the week with a close eye on the remanence of hurricane Marie which crossed the Atlantic and now threatened our fossil hunt.

Fortune persisted however, as although a bit windy and the sea choppy, we began the day dry and mild.

We began with an in depth talk about the geology by UKAFH leader Daniel Slidel. Exposed in the towering white cliffs of Seaford is the Upper Chalk, a Cretaceous deposit (Santonian-Campanian) about 86-83 million years old. Formed from the tiny platelets of coccolithophores – phytoplankton that was abundant in the deep, warm sea that existed here. This striking sediment helped preserve the creatures dwelling on the sea floor, which included bivalves, sponges, corals, bryozoan and the echinoids (sea urchins) this stretch of coastline is famous for. Within the cliffs are horizontal bands of flints which are visible as far as the horizon allows.

After a short walk from the car park we descended some concrete steps onto the beach. The abundance of fossil echinoids was immediately noted as within the exposed bedrock on the foreshore were the tell-tale circular marks of weathered echinoids in situ. We could not extract these as the bedrock here is protected, however this gave us ambition as we traveled west towards loose boulders from which we could extract specimens. It was not long before beautiful echinoids were being found loose or extracted from boulders. There were two genre found, Echinocorys and Micraster. These were found in chalk boulders preserved with delicately thin calcite test – however the flints on the foreshore should not be overlooked either as more robust and often sea rolled specimens for found here too. Other finds on the day included small bivalves, shapely sponges, coral and bryozoan.

As the afternoon drew late the atmosphere became heavy with the approaching storm and the first rain fell as we ascended the concrete steps back to the car park. Looks like we did it again and avoided the worst of the weather!

Thank you to everyone who attended this fossil hunt. It really was a great and friendly group of people, it was a pleasure to guide you through the Cretaceous geological history of Seaford.

Further Reading.

Hampton, M.J., H.W. Bailey, L.T. Gallagher, R.N. Mortimore and C.J. Wood 2007. The biostratigraphy of Seaford Head, Sussex, southern England; an international reference section for the basal boundaries for the Santonian and Campanian Stages in chalk facies. Cretaceous Research, v. 28, no. 1, p. 46-60.

UKAFH visit Seatown, 10th September 2017

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On September the 10th, (which was a very blustery day) UKAFH set off on a hunt towards Golden Cap from Seatown.

In the right scouring conditions when the ledges are uncovered from the shingle, Seatown beach can be incredibly productive with the Belemnite Marls exposed – bringing out countless iron pyrite ammonites, crinoid stems and belemnites. Unfortunately, despite the gale that was blowing, the ledges remained covered.

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Seatown beach on the 10th of September
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Seatown beach when the ledges are exposed.

We worked along the landslips on route to Golden Cap. The slips can produce green nodules (named because of the green calcite that makes up the preservation of the ammonites within). which contain many different ammonites, occasionally bivalves and very occasionally marine reptile remains. Within these nodule beds it is also possible to find parts of ammonites which have not been preserved within a nodule have been partially preserved. Many partially crushed Androgynoceras ammonites were found by members of the group, along with plenty of belemnites.

Once the group reached Golden Cap, we explored a little around the exposed Belemnite Marls and the landslips on the Seatown side (any further round, the wind became far too strong!). More belemnites and Androgynoceras ammonites were found. Despite the weather some great fossils were found!

Thanks to all who came along to Seatown and we hope you enjoyed the experience of

The new name of UKAFH

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We are pleased to announce we have changed the full title name of UKAFH. The new name “UK Association of Fossil Hunters’ works much better for the group than amateurs. We are always a family friendly group aimed at all levels, not just amateurs. We welcome beginners, and professionals too and of course amateurs will always remain closest to our group.

After much thought, we feel Association goes much better with who we are, and also retains our UKAFH abbreviated name!

So we welcome you to the UK Association of Fossil Hunters

UKAFH visit Ramsholt, 2nd September 2017

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