Winter Programme Lecture Abstacts
Dr Tory McCoy on October 4th 2017
Soft Tissue Preservation in Amber
Preservation of fossils in amber appears to be simple and perfect: an organism is entombed in resin, which hardens, protecting the carcass and ‘freezing’ it in time. However, although almost all fossils in amber look perfect to the naked eye, recent studies have revealed that this is often just an illusion. The best preserved specimens are indeed perfect, and include external cuticle as well as internal soft tissues such as flight muscles and neural tissues. In contrast, many other amber sites are simply hollow molds, stained to a life-like colour with remnant carbon. Actualistic taphonomic experiments reveal the factors that contribute to this variable preservation of fossils in amber, and influence our understanding of the amber fossil record.
Dr Roger Mason on October 18th 2017
Ediacaran fossils and Geoengineering in the Gorges of the Yangtze River, China
The Yangtze River is the third longest in the world, rising at 5,342m above the sea, on the Tibetan Plateau, and flowing east to the East China Sea. Its entire course lies in the People’s Republic of China. It was diverted eastwards from the Sichuan Basin, across central Chinese mountain ranges, by river capture, in relatively recent geological times, cutting three deep gorges. The rocks of the mountains had been thrown into arches and downfolds by a complex continental collision that ended about 200 million years ago. The eastern Xiling Gorge cuts through the highest anticline, down to Archaean rocks aged up to 3000 Ma old, which are intruded by a large mass of 800 Ma granite. This is the site of the controversial Sandouping Dam, which has an electricity generation capacity of 22,500 MW (about 1/6 of the maximum power transmitted through our British National Grid). The Precambrian crystalline rocks are overlain by a continuous succession of Proterozoic to Permian sedimentary rocks; including unmetamorphosed Cryogenian tillites; fossiliferous Ediacaran carbonates; and fossiliferous Cambrian and Ordovician rocks. My colleagues, from China Geosciences University in Wuhan, and I have discovered a continuous Ediacaran to Cambrian succession near the Dam that contains new, and yet, undescribed Ediacaran fossils. The top of the succession has a sharp boundary between white Ediacaran dolostone and black Cambrian shale, and we are continuing to search for fossils, and improve our description of the succession.
Professor David J Siveter on November 1st 2017
The Herefordshire Lagerståtte: Soft-bodied Virtual Fossils from a Silurian volcanic ash
Our understanding of the history of life on Earth relies heavily on the fossil record, and especially on rare cases of exceptional preservation, where soft parts of animals and entire soft-bodied animals are preserved. Such exceptionally preserved fossils provide an unparalleled view of animal palaeobiology and the true nature of animal biodiversity.
On-going research has recovered spectacular fossils from Wenlock Series Silurian rocks (~430 million years) of Herefordshire in the Welsh Borderland. Representing one of the rare Silurian exceptionally preserved fossil deposits, this biota of global importance contains representatives of many major groups of animals, including molluscs, echinoderms, brachiopods, polychaetes, and most especially a range of arthropods. The animals preserved are primarily epibenthic, but infaunal and nektobenthic forms are also represented. The fossils are preserved as three-dimensional calcite void-fills in carbonate nodules and are impossible to extract by standard methods. The specimens are studied using tomographic techniques to produce high fidelity three-dimensional virtual fossils that yield a wealth of palaeobiological information. These fossils are crucial in helping to fill a gap in our knowledge of the history of life and to resolve controversies about the relationships and evolution of animals still alive today.
Professor Mike Lovell on November 15th 2017
Petrophysics in the kitchen – cooking and baking tips for the festive season
Petrophysics is strictly, rock physics, and is the study of rocks at varying temperatures and pressure, over a period of time; the importance of the fluids cannot be overstated. Many of the concepts also apply in the kitchen, where a chef or cook can conjure up through art and/or science, a magical feast from seemingly simple ingredients. The range of food produced by an eminent chef, whether he is the angry one or the mad-scientist one, or she be the Nation’s treasure or simply a domestic goddess, is staggering. But this phenomenal range is perhaps equalled only by the strange and unusual behaviour in nature, in the distribution of gas, oil and water within a reservoir formation.
This talk looks at how Petrophysics is at times analogous to the physics and chemistry experiments we undertake in the kitchen and how understanding the properties of the components and their behaviour with temperature and pressure is the key. From stale bread to that perfect soufflé; a soft boiled egg to a perfect cold beer; all are underpinned by the interaction of solids and fluids at varying temperatures and pressures. And of course, we shouldn’t forget the peculiar properties of water which also affect the behaviour of reservoir fluids, and how the addition of salt to water may be significant, or not.
So come along for some topical tips on how to survive the festive season in the kitchen and an introduction to the wonderful world of petrophysics.
Rest assured, while there may be such a thing as a naked chef, on this occasion there will be no naked petrophysicist!