VOLUME 15 PART 4 JULY 2003 East Midlands Geological Society Contents President Vice-President Profile 194 Ian Thomas Tony Morris Ian Thomas – President Secretary Treasurer Mercian News 195 John Wolff Mrs Christine Moore Geobrowser Review Editorial Board The Record Dr Tony Waltham Tony Morris From the Archives Dr John Carney Gerry Slavin Dr Andy Howard Mrs Judy Small Ian Jefferson, Ian Smalley, Kevin Northmore 199 Consequence of a modest loess fall Council over southern and midland England Dr Beris Cox Tony Morris Miss Lesley Dunn Janet Slatter Jonathan D. Radley 209 Dr Peter Gutteridge Dr Ian Sutton Warwickshire’s Jurassic geology: Dr Andy Howard John Travis past, present and future Robert Littlewood Neil Turner Sue Miles Dr Alf Whittaker Peter Gutteridge 219 A record of the Brigantian limestone succession Address for Correspondence in the partly infilled Dale Quarry, Wirksworth The Secretary, E.M.G.S. 4 Charnwood Close, Trevor D. Ford 225 Ravenshead NG15 9BZ William Martin, 1767-1810, pioneer 0774 386 2307 [email protected] palaeontologist The Mercian Geologist is published by the East Reports 232 Midlands Geological Society and printed by Quaternary in Norfolk – Richard Hamblin et al Norman Printing Ltd (Nottingham and London) on Mitchell Caverns – Alan Filmer paper made from wood pulp from renewable forests. Landmarks of Geology 235 No part of this publication may be reproduced in The reef at High Tor – Peter Gutteridge any printed or electronic medium without the prior written consent of the Society. Lecture Reports 238 Crinoid decapitation – Stephen Donovan Registered Charity No. 503617 Crinoid adaptation – Mike Simms Midlands glaciations – David Keen © 2003 East Midlands Geological Society Loss of the Aral Sea – Tony Waltham ISSN 0025 990X Silurian soft bodied fossils – David Siveter Southern Britain – John Cope Cover photograph: East side of the Derwent End-Permian extinction – Paul Wignall Gorge just below Matlock, seen from the slopes of Masson Hill. The white limestone cliff bisects the Excursion Reports 252 High Tor reef (see landmark on page 235), while East Devon and Dorset coast Riber Castle stands on the Ashover Grit, and Ricklow and Lathkill Dales Chatsworth Grit forms the skyline [photo: Tony Waltham]. Index to Volume 15 255 PROFILE PROFILE Ian Thomas Ian, our new president, was born and brought up in Mansfield Woodhouse, Nottinghamshire, where two generations earlier his grandfather had worked the Parliament Quarry, on Vale Road (in the 1840’s the quarry was one of a number which supplied stone to rebuild the Houses of Parliament after a major fire). In 1957, his family moved to Aberystwyth (where great grandfather had sailed ships laden with lead ore). So geology was in the family blood. Ian’s interest in geology stemmed from a fascination for industrial history of the lead mines in Wales that he explored as a school boy. He read geology, biology, physics and geography at University of Swansea, graduating in geology in 1968 (having also taken a course in cartography). For four years he worked at the Institute of Geological Sciences (later to become BGS) in Exhibition Road, London – advising British and foreign governments and industry, on a portfolio of refractory, ceramic, carbonate and strontium minerals worldwide. Had BGS decided to move out to Keyworth at that stage, he would probably have still been working for them. Instead, in 1972 he joined Derbyshire County Council’s Strategic Planning Division to work on minerals policies for Britain’s largest mineral producing county. The following year, he set up the first Regional Aggregates Working Party (RAWP) (i.e. for the East Midlands) and continues as its Technical Secretary. At the Stone Centre, Ian is able to combine his In 1979 he became the Convenor of the RAWP passions for the history of quarrying, geology and Secretaries for England and Wales, which again he design. Ten years ago, nineteen members of the continues under contract to the Office of the Deputy Thomas family staged an art and design exhibition Prime Minister. He also became involved in adult ranging from Jaguar car designs to apples made from education, teaching applied geology in various applewood, and Ian still undertakes freelance design Derbyshire centres. work. In the 1980s, he promoted the idea of the National Apart from involvement in various local and Stone Centre (NSC) and gradually gained seconded national committees, covering the arts, tourism, time from the County Council to this end, becoming regeneration of Wirksworth, mining history and the Centre’s full time Director in late 1988. The building stone, Ian has just completed a two-year Centre opened to the public in 1990, and now term as chairman of ESTA (Earth Science Teachers’ attracts hundreds of school groups and thousands of Association). In 2002 he chaired the Standing Joint family visitors. In 1989, he was also appointed to Committee on Natural Stones, a group linking key BGS’s first Programme Board. professional and government organisations Two thirds of the work at the Stone Centre is concerned with building stones. unrelated to visitors. It includes the design of During this period, he became concerned that interpretative panels for leading quarry companies in ESTA was focused on catering for those teaching the Britain, collecting and publishing data on minerals few thousand school students studying geology per planning, and advisory services relating to Earth se. Not adequately addressed were the needs of the Science education for English Nature and the 8-10 million pupils being taught a more limited Countryside Council for Wales. amount of Earth Science (often poorly), through Much of Ian’s work is now involved with mainstream National Curriculum science. As a developing national policies for both the English and result, a small group approached the main Welsh governments for balancing the need to professional institutions concerned with chemistry, provide for aggregates with the need to protect the physics, biology and science teaching, successfully environment. In the last few years, the NSC has engaging them in the Joint Earth Science Education been more involved in Wales, including assessing the Initiative which Ian now Chairs – readers should scope for a Welsh Stone Centre. visit www.jesei.org to see some of the results. 194 MERCIAN GEOLOGIST 2003 15 (4) THE RECORD GEOBROWSER p.115). It changed the configuration of the landmasses, opening up a deep-sea gateway between the (equatorial) north and south Atlantic basins, Warm times each of which was formerly characterised by very different water temperatures and salinity. The The recent succession of years with anomalous ensuing vigorous circulation and mixing of waters climatic conditions, either excessively warm and dry, between the two former basins would have been or stormy, or both, has stimulated interest not only sufficient to bring about rapid and substantial in predicting future trends, but also in changes in temperature and salinity throughout the reconstructing past climatic regimes. Two major newly-enlarged proto-Atlantic ocean. global warming events are particularly well Tertiary warming: Global warming that occurred documented, but can we draw any lessons from in Palaeocene times, about 55 Ma ago, was of a these examples, that may help us to anticipate or similar intensity to that in the Cretaceous, but its even regulate future climate trends? causes were radically different. It was characterised Cretaceous warming: Probably one of the most by a massive and rapid (within a few thousand years) important discoveries of the past 20 years has been addition of isotopically light carbon to the oceans the recognition that the Polar landmasses of and atmosphere. In this global ‘greenhouse’, sea- Gondwana were warm, forested regions throughout surfaces had warmed by 4-8°C, to around 16°C off the Mesozoic and into early Tertiary times. A recent Antarctica, and the deep oceans by 5°C. The review (Journal of the Geol. Soc. 2001, p.709) notes thermal maximum then continued for a further that the global thermal maximum occurring in the 210,000 years (Geology, 2000, p.927), before Cretaceous Period, between 112-88 Ma (late recovery to more normal temperatures. Three Albian-Turonian), was characterised by broad- possible explanations have been proposed to leafed and conifer forests of warm-temperate aspect account for this change, and its rapidity: enhanced in Kamchatka and Russia (up to at least 82°N) and CO2 outgassing during emplacement of the North Antarctica (up to at least 75°S). Fossil tree-ring Atlantic volcanic province (of which the Tertiary structures indicate that the forests (with their volcanics of north-western Scotland are part); specialised dinosaur fauna) were adapted to long, dissociation of massive quantities of methane dark winters with average temperatures between 0°C hydrates along continental slopes; and a and -4°C, and long, light summers with carbonaceous bolide impact. The stable isotope temperatures of 20-24°C. records of Southern Ocean deep-sea cores had These proposals are difficult to reconcile with pointed to either seafloor methane outgassing or the suggestions that Cretaceous global sea-level bolide impactor explanations as being the most fluctuations were caused by temporary continental likely, but one line of evidence was missing. ice sheets in Antarctica (Geol Soc. America Bulletin, Vital to discrimination between these two models 2000, p.308). Strontium and oxygen isotope data is the answer to the question of which came