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Lectures |
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From October to March, a varied programme of illustrated lectures is presented. Speakers and topics are carefully chosen to provide interest for both the amateur and professional geologist. These meetings also provide an informal opportunity to chat to, or quiz other, perhaps more specialist members, and to gain advice from local experts on visiting geological localities. Each year, a celebrity lecture is given by a geologist of international repute, who is invited jointly by the Society and the Geological Society of Glasgow. At the annual Fellows' Night, members can give accounts of their own geological interests, specimens or travels. Even if you are not a Society member, you are warmly invited to come along. As well as the lecture, tea and biscuits are served afterwards (at no charge), giving you the chance to chat to other members and find out more. To find out a bit more, visit the About the Society page. The lectures are free and are held on Wednesday evenings. They begin at 7.30pm, and take place in the Hutton Lecture Theatre in the Grant Institute of Geology, on the University of Edinburgh's King's Buildings campus. View a map of the campus. Lecture programme 2007-20082007 17th Oct Dr George Reeves (Decommissioning
and Environmental Remediation Centre, Thurso) 31st Oct Dr Maarten Krabbendam (British Geological
Survey, Edinburgh) 14th Nov Prof Dianne Edwards (Cardiff University) 28th Nov (7pm) Presidential Address 12th Dec Dr David Martill ( University of
Portsmouth) 2008 16th Jan Dr Carrie Lear ( Cardiff University) 30th Jan Prof Martin Siegert (University
of Edinburgh) 13th Feb Prof John Mather (Royal Holloway
and Bedford New College) 12th Mar Fellows Night Wednesday 3rd October The Clough Memorial Award LectureThe Grampian Group: lithofacies at amphibolite facies Dr Christopher Banks The Neoproterozoic Grampian Group of the lower Dalradian Supergroup outcrops for 4250 km2 in the Central Highlands of Scotland. It was traditionally treated as undifferentiated siliceous and quartzofeldspathic schist (Hinxman and Anderson 1915) and early geological maps show a monotonous sea of psammite punctuated only by granitic intrusions. However, the Grampian Group comprises a demonstrable lithostratigraphy and locally preserves intricate sedimentary structures in low strain sections. Therefore, despite experiencing upper greenschist to amphibolite facies metamorphism, palaeoenvironmental and basin analysis is possible. The Grampian Group basins are interpreted as intracratonic failed rifts, comparable with other contemporaneous successions along the east Laurentian continental margin. Detrital zircon analyses indicate that these basins lay between 1.8 Ga aged Makkovikian-Ketilidian igneous basement to the west and c. 1.0 Ga aged Grenvillian/Sveconorwegian basement to the east. Wednesday 17th OctoberThe geoscience of radioactive waste diposal - challenges for the future Dr George Reeves Now that the UK has a recommended policy for the disposal of higher activity radioactive wastes at depth in suitable geological environments (CORWM, Final Report July 2006), it is a challenge for earth scientists of many specialisms, to investigate and explain to the hoped-for volunteer communities, the implications and expectations of the proposed underground developments and investigations that must be part of any repository programme. This talk will describe a number of international programmes into deep geological disposal of radioactive wastes, and show how experience, especially from Finland and Canada, can be used to guide a future investigation programme and developments in the UK. A novel approach to an underground demonstration facility to improve public understanding of the geoscience issues associated with deep geological disposal of radioactive wastes will also be discussed. Wednesday 31st OctoberA fluvial origin for the Morar Group, NW Scotland: implications for
Torridon-Morar Group correlation Dr Maarten Krabbendam Precambrian sedimentary successions are difficult to date and correlate. In the Scottish Highlands, potential correlations between the thick, undeformed siliciclastic Torridonian successions in the foreland of the Caledonian Orogen and the highly deformed and metamorphosed siliciclastic Moine succession within the Caledonian Orogen have long intrigued geologists. New and detailed mapping of the Neoproterozoic A Mhoine Formation (Morar Group, lowest Moine Supergroup) in Sutherland has discovered low strain zones exhibiting well-preserved sedimentary features. The formation comprises 3-5 kilometres of coarse, thick-bedded psammite with abundant nested trough and planar cross-bedding bedforms, defining metre-scale channels. Palaeocurrent directions are broadly unimodal to the NNE-ENE. We interpret the A Mhoine Formation as high-energy, braided fluvial deposits. The A Mhoine Formation and the unmetamorphosed, Neoproterozoic Applecross-Aultbea formations (Torridon Group), are similar in terms of lithology, stratigraphical thickness, sedimentology, geochemistry, detrital zircon ages and stratigraphical position on Archaean basement. Depositional age constraints for both successions overlap and are coeval with late-Grenvillean orogenic activity. Detrital zircons imply similar source regions from the Grenville Orogen. The Morar and Torridon groups can thus be correlated across the Caledonian Moine Thrust and are best explained as parts of a single, large-scale, orogen-parallel foreland basin to the Grenville Orogen. Wednesday 14th NovemberPlants invade the land: the Welsh connection Professor Dianne Edwards The invasion and colonisation of the land by green plants were events that changed the face of planet Earth and had impacts on the evolution of animal communities, atmosphere and lithosphere in the mid-Palaeozoic. The lecture will show how researches in Silurian and Lower Devonian rocks of South Wales and the Welsh Borderland have helped to elucidate the fossil history of the green invasion and the affinities of the plants involved, and from examination of different kinds of preservation, the anatomical innovations that permitted colonisation of the sub-aerial water-stressed environment. Reconstruction of vegetation enables assessment of its effects on the terrestrial substrate leading to the evolution of soils and even, via enhancement of chemical weathering, to the drawn-down of atmospheric CO2. Compared with the phenomenal record of animals in the Rhynie chert, body fossil evidence of terrestrial arthropods in southern Britain is sparse, but helps to reconstruct relatively simple food webs, dominated by detritivores and carnivores. Wednesday 28th November - this meeting will start at 7.00 pmThe Presidents lecture will be preceded by the Annual General Meeting of the Society Presidential address: How the Earth works - bringing exciting science to the public Dr Stuart Monro Many Nations are striving towards a knowledge-based economy. The roadmap towards this Utopia starts not with our scientists, not with our university students but in our schools. In many parts of the world there is at best an antipathy to school science and at worst downright hostility, a view often held by parents too. Kids think it just isnt fun or isnt cool, and parents that it isnt going to bring financial and career rewards, and both may harbour an image of scientists as interfering with nature. Yet, knowing how the Earth works is fundamental to many aspects of contemporary life. Natural Disasters face each and every one of us at some time or another. The global communications networks now bring any natural disaster and its consequences directly into our homes within hours. All of the resources we use are derived directly or indirectly from Earth processes. There is now a social responsibility to respond to major natural disasters and to address our use of resources. The lecture will explore how a more scientifically aware Society can be engendered and how it might respond in terms of understanding the Earths system. Why? Because the future of humanity might just depend on it! Wednesday 12th DecemberThe Chapada do Araripe Geopark of Brazil: two spectacular fossil sites in one basin Dr David Martill The Chapada do Araripe is a typical 'lost world' tableland of red sandstones underlain by a diverse sequence of limestones and heterolithic clastics. Two horizons, the Crato and Santana formations of Cretaceous age have become famous for the incredible diversity, abundance and exceptional quality of preservation of their fossils. The Aptian Crato formation yields an assemblage of insect, fish, pterosaurs and the best arachnid fauna of the Mesozoic. The slightly younger Santana Formation yields fossils within carbonate concretions that include some twenty or more species of fish, perhaps a dozen pterosaur species and the odd dinosaur. Remarkably, many of the fossils in the concretions have soft tissues preserved in 3-D. Scanning electron microscope studies of these exceptional fossils reveal details of the musculature, gill filaments, gut lining and, in the case of the pterosaurs, provide fascinating insights into the structure and physiology of the wing membrane. A thriving international trade in these fossils exists. Some argue that the trade is essential for palaeontology, while others argue against it. The region containing these remarkable deposits has been declared a World Geopark, and although the illegal trade in fossils continues, scientists find obtaining permission to work there difficult to obtain. Thursday 10th JanuaryThe Joint Celebrity Lecture is hosted in alternate years by the EGS and the Geological Society of Glasgow, This years lecture will take place in the Gregory Building of the University of Glasgow at 7.30 pm. The Astronomical Society of Glasgow are also attending the lecture. The search for life beyond Earth Professor Monica Grady The question of whether we are alone in our Universe has fascinated humanity since the earliest of times. The talk will explore our own planet with a look at how life first came about and the range of environments in which it has adapted to survive. Studying organisms that live in the most extreme and inhospitable habitats provides a guide to the limits of life on other planets. The lecture will then move on to consider places in our Solar System where life might be found, particularly Mars and Europa. Wednesday 16th JanuaryCenozoic climate change: insights from foraminiferal trace metal proxies Dr Carrie Lear Two independent geochemical proxies suggest that in the early Cenozoic, concentrations of atmospheric carbon dioxide were several times higher than pre-industrial levels (Pearson et al., 2000; Pagani et al., 2005). At this time there were no continental-scale ice sheets, and cold-blooded reptiles lived within the Arctic and Antarctic Circles. The Cenozoic can therefore be used to test climate models, by comparing model predictions for past greenhouse conditions with quantitative climate records derived from geochemical proxies. 1 The formation of the Antarctic ice sheet has been simulated by a climate
model forced with declining levels of atmospheric CO2 (DeConto and Pollard,
2003). This model predicts that once pCO2 had dropped to between 2 and
3 times pre-industrial levels, a large ice sheet formed on Antarctica,
whilst the Arctic remained largely ice-free. In contrast, geochemical
proxy records of Earths Greenhouse-Icehouse Transition at the Eocene-Oligocene
boundary can be interpreted as the formation of an ice sheet too large
to be accommodated solely on Antarctica. Pagani, M., Zachos, J.C., Freeman, K.H., Tipple, B., and Bohaty, S. Marked decline in atmospheric carbon dioxide concentrations during the Paleogene Science 309, 600-603, doi: 10.1126/science.1110063 (2005). Pearson, P.N., and Palmer, M.R. Atmospheric carbon dioxide concentrations over the past 60 million years Nature 406, 695-699 (2000). DeConto, R.M., and Pollard, D. Rapid Cenozoic glaciation of Antarctica induced by declining atmospheric CO2: Nature 421, 245-249 (2003). Lear, C.H., Rosenthal, Y., Coxall, H.K., and Wilson, P.A. Late Eocene to early Miocene ice-sheet dynamics and the global carbon cycle Paleoceanography 19 PA4015, 10.1029/2004PA001039 (2004). Wednesday 30th JanuaryThe exploration of Antarctic subglacial lakes Professor Martin Siegert Over 145 lakes are known to exist beneath the Antarctic ice sheet. They range in size from a few hundred metres in diameter to the colossal Lake Vostok, which is over 240 km long. Since the discovery ten years ago that Lake Vostok had a water depth in excess of 500 m, biologists have considered subglacial lakes to be extreme environments where microorganisms, adapted to the distinctive conditions at the ice sheet base, may survive. In addition, geologists believe sediments at the floors of subglacial lakes may contain unique records of ice sheet and climate history. Hence, there are very good scientific reasons to undertake the exploration of subglacial lakes. Plans to explore subglacial lakes have been in a phase of development for the past ten years, despite four major international conferences to advance the situation. The problem is two-fold. First, undertaking direct measurement and sampling of a subglacial lake requires a huge logistical investment. Second, such exploration must guarantee against contamination of these pristine systems. Despite an international programme set up by the Scientific Committee on Antarctic Research to oversee the exploration of subglacial lakes, plans for the work remain varied and contentious. The way forward requires consultation with, and agreement among, the members of the Antarctic Treaty. As a consequence, subglacial lake exploration has a political edge that is unusual in science. Nevertheless, several plans for subglacial lake exploration are being developed, including a Russian-led proposal to drill into Lake Vostok and a UK-led scheme to explore Lake Ellsworth in West Antarctica. These plans aim to unlock the scientific secrets of subglacial lakes within the next ten years. Wednesday 13th FebruaryThe geology of bottled water Professor John Mather Most bottled waters originate as groundwater, the composition of which is controlled by a number of interacting processes. Thus certain geochemical characteristics, such as the magnesium/calcium ratio, are determined by the host rock, chloride concentrations may be controlled by atmospheric inputs and sulphate and nitrate by mans activities. An understanding of these processes enables the hydrogeologist to unravel the geochemistry of individual bottled waters and say something about their origin. A number of bottled waters from the UK and overseas will be reviewed and their compositions interpreted in terms of rainwater inputs, water/rock interaction and groundwater flow paths. The excesses of the advertising industry are well illustrated by bottled water labels and a range of such labels will be examined. It is concluded that in the UK bottled water is unlikely to be any improvement on local piped supplies and certainly no safer. Wednesday 27th FebruaryPresentation of the Clough Medal Building the grampian orogen: architecture and kinematics Dr Geoff Tanner It is a fitting tribute to Charles Clough that this lecture should begin by describing the geology of Cowal, as this is where he made his greatest contribution to structural geology. In the 1897 Memoir he recognised that folds and fabrics can be refolded on a regional scale, and was the first to see the significance of stretching lineation and strain bands. Had the methodology for determining way-up in rocks been available, Clough would almost certainly have discovered the Tay Nappe. Over a century later, the best representation of the structure of the Grampian terrane is the cross-section between Bute and Islay. However, before using this kinematically-challenged cross-section (in which the axial surfaces of the primary folds NW of the Cowal Antiform fan through >90º) as a basis for modelling, its reliability had to be checked. The field data used for this purpose will be illustrated and discussed, together with new field evidence for the transport direction of the Tay Nappe during D2. Several conflicting and unsatisfactory models have been proposed to explain how this complex Grampian structure evolved. A new model is proposed in which NW-directed subduction of the floor (serpentinized continental mantle) of a back-arc basin located between the Midland Valley arc and Laurentia occurs throughout D1-D3. The Highland Border Ophiolite is a slice of this floor obducted on to the Dalradian block following the formation of the Tay Nappe. Finally, the new model is tested against the more complex geometries seen in sections farther NE. Wednesday 12th March
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