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!
Professor Colin Waters on November 29th 2017
The Anthropocene: an over view of the geological evidence, and ongoing work on its definition
This presentation outlines the work of the Anthropocene Working Group in gathering evidence to constrain and assess the Anthropocene as a potential new formal chronostratigraphic unit within the Geological Time Scale. Human activity is leaving a pervasive and persistent signature on Earth and vigorous debate continues about whether this warrants recognition as a new geologic time unit. Evidence includes the appearance and rapid dispersal of many new mineral forms (including metals, plastics and industrial fly ash), rock types (including concrete) and sediment bodies including artificial ground, together with sediments released by land use changes. Humans now move more terrestrial sediment than all natural fluxes by rivers, wind, and glaciers. Chemical signals include isotope patterns altered by perturbations to the carbon and nitrogen cycles at rates and magnitudes unprecedented in Quaternary times, atmospheric gas changes preserved in ice, disseminated metal and persistent organic pollutant and artificial radionuclides traces, many of which are novel signatures. Biological evidence includes the consequences of extinctions, geologically unprecedented species invasions and marked assemblage changes. Recent climate and sea level trends are outside the Holocene trajectory, though global temperature and sea level are still within the Quaternary interglacial envelope. Anthropogenic influence on stratigraphic signals commenced thousands of years ago, but the most pronounced inflection in most global trends away from Holocene patterns is in the mid-20th century. The presentation will also describe ongoing plans for developing a proposal for a formal “golden-spike” section, looking at some of the potential host environments.
Dr David Holwell on January 10th 2018
Exploration for Nickel in Zambia and southeast Africa… sourcing the power for the electric car revolution
The massive increase in the predicted shift to electric cars in the coming decades means that the demand for metals used in batteries is increasing significantly. One of the key metals required in lithium ion batteries, used to power electric cars is nickel and thus battery makers s are increasingly turning to nickel to help power growing global electric car sales. Nickel, along with other key environmentally significant elements used in the automotive industry (platinum group elements – PGE - in catalytic converters) are found in very specific geological environments. Nickel, copper and PGE are found in magmatic setting where mafic and ultramafic magmas host metal-rich sulfide deposits. Key locations for these are around the margins of ancient cratonic crust, and one such area – between the Congo and Kalahari cratons – is a key potential site for discovering new deposits of these technologically important metals. This talk will cover the future demand of Ni and the PGE by the changing automotive industry, and by way of using Zambia and its neighbouring countries, show the key geological controls from the mantle up into the crust that are required to produce these deposits, and how we can use knowledge of these to make predictive exploration models.