ChaSE Project

Selected structural features in southern England, the English Channel and northwest France. The distribution of the correlative Tilleul and Ogbourne Hardgrounds is shown; these are absent to the north-east of the Wight–Bray Fault and associated with Variscan basement thrusts across central southern England. The section at Winterbourne Kingston, on the Litton Cheyney Fault, shows a conglomerate of older Cretaceous debris derived from the overthrust hanging wall, deposited on a surface correlative with the Ogbourne Hardground (Gale, 2019a). The Ogbourne Hardground is absent in the marginal successions in Devon. 'Strahan's Hardground' at Lewes, East Sussex, is correlative with the Ogbourne Hardground. Map modified from Wikimedia Commons.

Identification of marker marl beds in the lower and middle Turonian of the northern Anglo-Paris Basin. See text for detailed explanation.

Geological map of the area adjacent to the English Channel, to show the Cornubian and Armorican Massifs and the Turonian depocentre. This study focuses on successions on the Devon and Seine-Maritime coasts, where the successions thin towards the basin margins. Map modified from Wikimedia Commons.

Front cover of the scientific journal Proceedings of the Geologists' Association.

Correlation of the lower and middle Turonian chalks of south-west England and north-west France - condensation towards the Cornubian and Armorican massifs by Andy Gale

In Proceedings of the Geologists' Association, vol 137, issue 1, Feb 2026: www.sciencedirect.com/science/arti...

Two large rudist shells belonging to the genus Durania preserved in chalk, sitting in a box in a white metal drawer.

A white metal drawer containing a selection of fossil rudist bivalves from the Chalk.

A cylindrical specimen of the rudist bivalve Durania from the UK Chalk.

A cross section through a rudist bivalve fossil preserved in the chalk showing its distinctive porous shell structure.

#MolluscMonday is all about rudists! These unusual bivalve molluscs were very common in the Late #Cretaceous, especially in tropical settings around the Tethys Ocean. Individual or conjoined specimens occasionally appear in the UK Chalk but are often poorly dated.

Emma on stage in Meeting Room Hall 4 with her title slide.

Emma Bernard presenting her research as part of @chalksea.bsky.social that samples chalk nannofossils fossils from over 1000 Cretaceous fossil fish specimens at @nhm-london.bsky.social to significantly clarify their stratigraphic context.

Meeting Room Hall 4
#2025SVP
#SVP2025

A fossil coelacanth (Macropoma) from the Chalk in a drawer in the NHM London collections.

Well preserved fossil fish from the Chalk in the NHM London collections.

#FossilFriday at #SVP2025 today! Emma Bernard will be talking about dating the amazing @nhm-london.bsky.social chalk fish collections at 09:30 in Hall 4. Then check out posters by Twitchett/Underwood and Kaia Spence on new #chalk sharks & coelacanth size in Poster Session III, Hall 3 (4:30 - 6:30).

A great time was had at the 'Festival of Geology' today! Thanks @geolassoc.bsky.social and @geolsoc.bsky.social for having us, and to all the enthusiastic visitors who were interested in our work. Thanks especially to @spissatella.bsky.social and Tessa for sharing your knowledge and helping out.

The library of the Geological Society of London with tables set out for the Festival of Geology.

A series of chalk fossils and information about life in the chalk seas.

If you're in #London today then come along to the @geolassoc.bsky.social FREE 'Festival of Geology' @geolsoc.bsky.social on Piccadilly. We'll be there showcasing some #chalk fossils and talking about our work on #Cretaceous ecosystems and environmental change. Come and say hello!

A billboard on the side of a large building advertising the Geological Society of America Connects 2025 conference.

A man stands at a podium delivering a scke tirich talk. On the screen are images of chalk cliffs and a map.

A large poster on a black board.

Great to be in San Antonio, Texas this week! 🇺🇸 We were at the @geosociety.bsky.social annual meeting, where @jdwitts.bsky.social & project PI Rich Twitchett presented a talk and poster on the latest science from ChaSE, studying #Cretaceous environmental and marine ecosystem change.

#FossilFriday This large slab in the NHMUK covered with screws of the Carboniferous bryozoan Archimedes was unknown to me until last week. For at least 46 years it has been lurking among large specimens in the coral collection.

A museum drawer full of ball-shaped crinoid fossils.

A fossil crinoid belonging to the genus Marsupites

A pencil drawing of the test (skeleton) of the crinoid Uintacrinus.

A pencil drawing of a crinoid skeleton.

Historic specimens of the unusual #Cretaceous crinoids Marsupites and Uintacrinus @nhm-london.bsky.social made by Dr Arthur Rowe in the 1900s, including some beautiful pencil drawings. These extinct 'sea lilies' are abundant at certain levels in the #chalk making them useful for global correlation.

An outcrop of chalk with a tape measure for scale. A prominent layer of dark shale - the 'Black Band' - runs through the middle of the sequence.

A large chalk pit under a blue sky. A man in a high vis jacket and hard hat is examining the rock outcrops.

A close up of a finely laminated rock showing small fossil burrows- proof thst even during an 'Ocean Anoxic Event' there was life on the sea floor.

A red poppy growing on rubbly chalk.

#FossilFriday from the chalk seas of #Yorkshire - a good day in the field yesterday sampling a working chalk pit containing outcrops of the 'Black Band'; corresponding to #Cretaceous Ocean Anoxic Event 2. Thanks to the folks at Ashcourt Group for facilitating our visit!

Slimehead Size Through Time: Testing the Temperature–Size Relationship in Late Cretaceous Trachichthyidae In this study, we use the extensive fossil record of the extinct Late Cretaceous Trachichthyid fish genus, Hoplopteryx, from the British Chalk Group to explore how this family responded to past clima...

🚨New ChaSE paper!🚨 'Slimehead Size Through Time'. Led by Masters student Chloe Griffiths, we used #chalk collections @nhm-london.bsky.social of the 🐟 genus Hoplopteryx & stable isotope analyses @ucl.ac.uk to see how fish body size varied with #Cretaceous climate change. 🌡📏 doi.org/10.1002/ece3...

A large quarry with a face made of chalk, a dark grey band runs across the center of the face. The sky is blue.

A fossil echinoid with a scale bar and arrow pointing to the fossil.

A fossil belemnite embedded in rock with a scale bar.

A fossil gastropod (snail) with a tape measure for scale.

A good day in the field logging and sampling at high resolution new site containing a record of #Cretaceous 'Ocean Anoxic Event 2' (can you spot it?) near Ringstead, #Dorset yesterday. Plenty of finds for #FossilFriday including sharks, sea urchins, sponges, belemnites and fish!

A poster on the work of the Chalk Sea Ecosystems project.

Great to be in Hannover at the 12th #Cretaceous Symposium! @jdwitts.bsky.social is presenting an overview of our #Chalk project @nhm-london.bsky.social @ucl.ac.uk

Picture in your mind a shark tooth... We bet this isnt the shape you were thinking of!

The shark Ptychodus had a 'pavement' of these strange teeth for crushing hard-shelled prey. Ptychodus fossils have been found all over the world, including from Hessle near Hull.

🏛️ Sedgwick Museum #FossilFriday

Some of today's #chalk views at Eastbourne. 🚁 🐚

A man holding up an ornately written certificate

A flint nodule containing a fossil sponge in a white box. Two labels identify it as Plinthosella from the upper chalk, Seaford Sussex

#FossilFriday. In 1950, 10-year-old Stephen found a fossil #sponge on the beach at Seaford, East Sussex & donated it @nhm-london.bsky.social. 75 years later, Stephen visited us to see the specimen! Thanks to all the #ChalkHeroes who donated their finds over the years and make our research possible.

A laboratory work bench with a microbalance, some glassware, and tubes filled with white powder

A view looking up through some trees to a blue sky

Yesterday was #MicrobalanceMonday. Working at the Bloomsbury Environmental Isotope Facility @ucl.ac.uk weighing out #chalk samples for carbon & oxygen isotope analyses. These will tell us about both temperature and carbon cycling in the chalk sea. UCL campus also has some lovely spots for a break!

A large fossil clam embedded in a grey rock with a black-and-white scale bar.

A large clam fossil embedded in a grey rock with a black-and-white scale bar.

A large clam (labelled 37) and a sponge (38) fossil embedded in grey rock with a tape measure for scale.

Fossils of a large clam (56) and sponge (57) embedded in a grey rock with a yellow tape measure for scale.

#MolluscMonday a selection of inoceramid bivalves (and bonus sponges!) from the late Cenomanian Plenus Marls at #Eastbourne. These rocks were deposited during a period of #Cretaceous climate change known as 'Oceanic Anoxic Event 2', but these unusual clams don't seem to mind.

Highlighting a new paper from our team for #FossilFriday! On the discovery and diversity of bone-eating worms in historically collected marine reptile specimens @nhm-london.bsky.social from the UK #chalk.

A man stands at a podium in front of a dcreen advertising 'Life and Planet 2025'

Two scientific posters set up in a library.

Looking forward to a fun few days of science and catching up with coclleagues @lifeandplanet.bsky.social @geolsoc.bsky.social. Our @chalksea.bsky.social project has two posters and a talk on #Cretaceous environmental change and effects on marine ecosystems. Come and say hello!

A group of smiling people stand behind a table which is covered by fossils and pictures of chalk fossils.

A large poster with a reconstruction of a water column on which people have drawn reconstructions of fossil animals on stickers.

It's the final day of the #FossilFestival at Lyme Regis! Still time to join our team in The Hub to learn about our science reconstructing #Cretaceous ecosystems, handle some chalk fossils from @nhm-london.bsky.social, and draw your own #ChalkSea creatures.

A group of people working for the Natural History Museum stand behind a table of fossils in a marquee.

A poster representing an ancient seafloor environment covered in drawings of fossils

We had a great first day at Lyme Regis #FossilFestival talking to a lot of visitors from local schools, somem fabulous additions to our #chalk ecosystem! If you fancy drawing your own #Cretaceous creature and learning more about our project, we're in The Hub today!

An exposure of rock (chalk) mostly white and grey. A distinctive black and grey layer runs horizontally through the center of the photo. There is a geological hammer for scale at the base.

A sea arch cut into white chalk cliffs with a field of boulders in the foreground. The chalk shows obvious bedding and dark grey flint layers.

A man in a black coat and white hard hat looks at a cliff of white chalk showing obvious layering.

A man in a high visibility jacket uses a geological hammer to expose layers of rock at the base of a low cliff.

Fun few days #fieldwork touring and logging beautiful Cenomanian - Campanian chalk outcrops in North Lincolnshire and Yorkshire with Prof Andy Gale and Paul Hildreth. Including exposures of the 'Black Band', the northern expression of #Cretaceous Oceanic Anoxic Event 2.

Three people stand talking in front of a cliff made up of distinct bands of light and dark coloured chalk.

A fossil echinoderm in white chalk. A finger for scale!

The impression of a large fossil Nautilus in grey chalk. A black and white scale bar is at the top of the photo.

A tiny star-shaped ossicle from a fossil crinoid in the chalk. With a finger for scale.

Lovely day in the field at Culver Cliff (Isle of Wight) with @echinerd.bsky.social and PhD student Chia-Hsin Hsu. We looked at the beautifully bedded Cenomanian-Turonian #chalk, finding plenty of echinoderms, bivalves, serpulids and even a nice nautilid!

Skeleton of a fossil coelacanth fish (Macropoma mantelli) preserved on a block of chalk. A cm scale bar is present at the top.

A beautifully preserved fossil fish (Ctenothrissa radians) complete with scales, sitting on top of a block of chalk on a white background. A cm scale bar is at the bottom left.

A person measuring a fossil fish skeleton using a pair of digital calipers.

A tiny fossil fish skeleton preserved in a block of chalk. The scale bar above shows it is only 3cm in size.

#FossilFriday Chalk Sea fish, big and small! From the amazing historic chalk collections of Booth Museum of Natural History in #Brighton. Part of ongoing research to understand how these fish were affected by #Cretaceous climate change. 🐟🌡

D'oh! The perils of tagging on social media.. I thought that account was for the council. 😅 Though @officialbha.bsky.social are of course based on top of the #chalk..

A well-preserved fossil fish skeleton sitting in chalk matrix within a wooden box.

Someone using a razor blade to scrape chalk matrix off the side of a fossil skeleton onto a piece of paper.

A fossil fish skeleton set in chalk. A small area of the matrix is visibly whiter where a sample has been taken for stable isotope analysis.

#MacropomaMonday - MRes student Kaia Spence is at UCL this week, preparing samples of chalk matrix for stable isotope analysis. By comparing oxygen isotope/temperature data with morphometric measurements from fossils, Kaia is examining how body size in coelacanths was affected by climate change.

A man with dark hair and glasses examines fossils in chalk blocks from a wooden drawer.

Several pieces of chalk containing unusually shaped fossil sea urchins. A label says they are from Yorkshire.

Welcome to new PhD student Chia-Hsin Hsu from @unisouthampton.bsky.social - Chia-Hsin will be studying morphological evolution of echinoids from the #Cretaceous chalk sea. Including these beautiful Hagenowia from #Yorkshire.

A man stands in front of a large chalk cliff. A geological hammer rests on the ground.

A large fossil clam in chalk with a scale bar.

A white chalk outcrop with brown structures (fossil sponges!), and grey fossil burrows.

A beach filled with boulders in front of a large white chalk cliffs.

First #fieldwork of 2025 ☑️. Good day at #Eastbourne with @chalksea.bsky.social project collaborator Dr Charlie Underwood, collecting samples and surveying the #Cenomanian Plenus Marls. Plenty to think about, & fossil sponges, bivalves, brachiopods, and echinoderms galore!

A drawer full of fossil snail shells preserved in white and grey chalk.

More snail shells preserved in chalk in a wooden drawer.

A large fossil snail showing well preserved shell structure.

A fossil snail with original shiny nacreous shell preserved.

🐌 are quite rare in the #chalk as their aragonite shells dissolve easily. An exception is the Family Pleurotomariidae or 'slit snails', sometimes with original shiny nacreous shell on display for #FossilFriday