2016 Geologists’ Association Annual Conference
The Jurassic Coast: geoscience and education
21s t - 22nd October 2016
Portland Heights Hotel, Isle of Portland
The Geologists’ Association’s 2016 annual conference will be held on the Jurassic Coast. Celebrating 15 years since the inscription of the World Heritage Site the conference will review and explore current geological research on the Jurassic Coast. Triassic, Jurassic, Cretaceous, Quaternary and geomorphological interests will all be catered for as we bring together the diverse geology that has created England’s only natural World Heritage Site.
The conference will also share the innovative approaches to linking geoscience, heritage and people that have been developed by the Jurassic Coast World Heritage Team. This will include the educational, volunteering, interpretation and arts programmes that have brought the communities and visitors of the Jurassic Coast closer to their geological heritage.
On day 1 conference speakers include Professor Mike Benton (University of Bristol), Dr David Martill (University of Portsmouth), Professor Malcolm Hart (Plymouth University) and Professor Rory Mortimore (Chalkrock). Tim Badman (International Union for the Conservation of Nature) and Professor Denys Brunsden will bring a wider World Heritage perspective to the meeting.
On day 2 field visits will provide the opportunity to see the spectacular Kimmeridgian Etches Collection (www.theetchescollection.org) in its new home ‘The Museum of Jurassic Marine Life’ and recently conserved dinosaur footprints on the on the Isle of Purbeck.
To find our more details go to the GA website www.geologistsassociation.org.uk/conferences.html and to make a booking please email: firstname.lastname@example.org
The conference will be organised and supported by the Geologists’ Association, Jurassic Coast World Heritage Team, Natural England and the Dorset Geologists’ Association Group, and is sponsored by Elsevier.
The Heights Hotel have offered delegates a preferential rate of £90 per night room and breakfast sole occupancy; £90 Double/Twin £110 per room per night and breakfast.
You will need to ring the hotel direct on 01305 821361 and quote “Geologists’ Association conference” to get this rate, do not book through the website. www.heightshotel.com
The Jurassic coast first came to notice scientifically through the discovery of ichthyosaur, plesiosaur, and pterosaur specimens by Mary Anning more than 200 years ago. Since then, fossil vertebrates have been found at numerous levels through the Triassic, Jurassic, and Cretaceous portions of the coast sections. The continuing discovery of specimens, publication of revisions of older material and announcement of new discoveries, as well as the development of museums old and new, have kept the vertebrate palaeontological aspects of the Jurassic Coast well to the fore. I will describe a little of the history, but concentrate more on research work in the last ten years, in which new methods such as CT scanning and engineering analysis have been used to understand the jaws of the largest sea dragons, and numerical studies have cast unexpected new light on patterns of evolution and the impact of the Triassic-Jurassic mass extinction on reptile evolution.
Cretaceous gems of the Jurassic Heritage Coastline
ChalkRock Limited, 32 Prince Edwards Road, Lewes, Sussex, BN7 1 BE
Perhaps the most spectacular features of the Jurassic Coast are the exposures of steeply dipping Upper Cretaceous Chalk forming the Ridgeway and Purbeck Hills, the back drop to the embayments cut into coastline from White Nothe to Worbarrow Bay at Durdle Dor, Lulworth Cove and Mupe Bay. No less spectacular are the Chalk cliffs at Beer and Seaton in the west or Ballard Point and Handfast Point in the east. Despite these magnificent Cretaceous exposures their detailed geology is relatively poorly known. Yet hidden within these cliffs is the evidence for sea-level fluctuations represented by overstepping formations, structural controls on sedimentation history and consequent ecological niches controlling the distribution of fossils and the structural evolution of the region. Many of the cliffs are near vertical and dangerous to measure, however, the numerous fallen blocks yield sufficient detail to recognise key lithological marker beds and fossils that link the geology of the cliffs to inland exposures and to the rest of the region. Such detailed information enhances the study of the structural geology for which the coastline is justly famous. New information from recent road construction has enhanced our knowledge of all these aspects of the Cretaceous geology of the Jurassic Coast World Heritage Site.
Mapping the Great Undercliffs landslides
The Undercliff National Nature Reserve between Lyme Regis and Axmouth contains three great landslides; the Plateau, which is prehistoric in age and the Bindon and Dowlands complexes which created Goat Island and the Chasm during Christmas 1839. Sixteen acres of land became isolated by the formation of a 65m deep chasm. Buckland and Conybeare thought that the failure surface was the unconformity. Since then variations on a rotational failure have been put forward and challenged.
The nearby Plateau foreshore has been mapped in great detail. It shows that there are multiple failure surfaces within the Jurassic strata, that they are deformed by later failures and that some of the same strata can be seen both ‘in situ’ and actively extruding in close proximity, indicating a listric shear surface. The entire Cretaceous, Jurassic, and the highest
Triassic strata are rotated in the complex and therefore the failure surface cannot be the unconformity.
The Plateau looks rotational but a translational landslide can also cause rotation of the slipped blocks and create listric movement in the toe. The Bindon landslide is even more problematic with little clear evidence of the failure surface. That said, the complex starts abruptly with insufficient room to accommodate the displaced strata above the unconformity. The displaced strata in the Chasm are also difficult to accommodate as the unconformity lies approximately 20m below the floor of the Chasm. Therefore the failure surface must be deeper but it is not possible to determine it without physical or geophysical investigation and 3D computer modelling. A resistivity survey was undertaken by Plymouth University in February 2016 and the results are eagerly awaited.
Ear bones and hooks: a micropalaeontological approach to investigating Jurassic squid-like cephalopods
Malcolm B. Hart
School of Geography, Earth & Environmental Sciences, Plymouth University, Drake Circus, Plymouth PL4 8AA, United Kingdom
In many micropalaeontological samples of Jurassic age collected in the Wessex Basin ear bones (statoliths) and hooks (onycites) of ‘squid’ are associated with the usual assemblages of foraminifera and ostracods. Statoliths are the small, paired, aragonitic stones found in the fluid-filled cavities (or statocysts) within the cartilaginous heads of all modern and probably all fossil coleoids. Onycites are the small, hardened organic hooks that are found in the arms and tentacles of modern and fossil squid. While these slightly unusual microfossils have been known for ~100 years (or more), they were curiosities rather than significant indicators of cephalopod evolution. Our understanding of both statoliths and onycites changed with the investigation of the Christian Malford lagertstätte in Wiltshire. At this locality, in both excavations and cored material, very significant numbers of statoliths and onycites were found, closely associated with exceptionally preserved Belemnotheutis antiquus Pearce, Mastigophora brevipinnis Owen, Romaniteuthis sp. and Trachyteuthis sp. Some of these fossils preserve muscle tissue, content of ink sacs, and other soft parts of the squid, including tentacles with hooks in-situ and the head area with statoliths present in life position.
Using material from across Wiltshire, Somerset and Dorset, it is hoped to identify which statoliths and onycites are associated with specific host animals and, using these microfossils, determine the complete ranges and possible evolution of the fossil squid. This is not as easy as it sounds as, on the Charmouth coast, in Bed 88f of the Lias Group one finds the statolith ‘Jurassic sp. B’ in the same sediments as Phragmoteuthis huxleyi Donovan and P. montefiorei J. Buckman but, until a specimen of the fossil squid containing the statolith is found, then it is just a ‘coincidence’.
It is known that both the statoliths and onycites are found all over Europe in the Jurassic (Hettangian–Kimmeridgian) and comparable onycites have been recorded on the Falkland Plateau and in New Zealand. If these microfossils are genuinely inter-continental in their distribution, and can be related to specific taxa, then they should help in the determination of both the palaeogeographical distribution and evolution of the squid-like cephalopods.
The geology of gravestones
Nina Morgan (geologist and science writer based near Oxford) and Philip Powell (Honorary Associate and former curator of geology at the Oxford University Museum of Natural History)
For geologists – whether amateur, student or professional – almost any cemetery provides a valuable opportunity to carry out scientific field work at leisure, right on the doorstep, and at no cost. Because gravestones are made from a wide variety of rock types formed in a range of geological settings, cemeteries can be geological treasure-troves. A visit to a cemetery offers a wonderful introduction to geology and the other sciences, such as chemistry, physics and engineering, that underpin it.
Many gravestones are made of polished stone, so reveal details – such as minerals and crystal features – that are not easy to see elsewhere. Some demonstrate the textures and mineral composition of igneous rocks. Others are happy hunting grounds for fossils. Some gravestones reveal sedimentary structures that show how the rock was originally deposited. Others provide clues to Earth movements and environments that occurred hundreds of millions of years ago. For those interested in engineering, examination of gravestones can also provide useful information about topics ranging from weathering of stone to atmospheric chemistry, effects of pollution, stability and settling in soils and land drainage.
Cemeteries also document the evolution of transport systems and advances in stone cutting and polishing technology. While 18th C gravestones in churchyards tend to be made of local stone, the range of rocks used for gravestones expanded rapidly during the 19th C, as first the canal, and later the railway, networks were developed. In the second half of the 19th C the introduction of steam saws and lathes led to the more common use of hard rocks such as granites for gravestones. Now that it is easier and cheaper to transport stone from all parts of the world the use of 'exotic' and decorative stones from places such as South Africa and India for gravestones is very common, particularly in modern municipal cemeteries.
Although this poster is based on examples from geological trails in six cemeteries in Oxford which are documented in a new book, The Geology of Oxford Gravestones, the rock types and geological features illustrated can also be recognised in many other parts of Britain. We hope that this poster will encourage you to explore the geology on show in cemeteries in other areas. You'll never look at cemeteries in the same way again.