Synopses of Talks through the 2020 - 21 Winter Season
Wednesday 8th July
Contrasting Islands: the geology of Eigg and Rum
Angus Miller (Secretary Scottish Geology Trust)
The Hebridean islands of Eigg and Rum are separated by just a few miles of sea, but could hardly be more different in their scenery, topography and land use. Of course this is due to the underlying geology. Both islands have a basement of sedimentary rocks (formed 800 million years apart!). Then, 60 million years ago, this area was a focus of volcanic activity: Eigg is mostly formed by the eroded remains of extensive basalt lava flows; whereas Rum was the site of a central volcano. It is a fascinating clash of rock types and morphologies that has formed two contrasting islands.
Wednesday 19th August
Mining in North Wales
Robert W. Vernon BSc MSc PhD CGeol FGS (Rtd)
Parys Mountain Copper Mine, Anglesey
This talk will begin with an introduction to the geology of North Wales before discussing the most important minerals worked (copper, lead, gold, slate, coal and a few “miscellanea”). We will then take a round trip of the various mining districts, including perhaps the best known copper mine in Wales (at Parys Mountain on Anglesey), as well as the Parc lead and zinc mine at Aberconwy, and the Gilfach copper mine in Caernarvonshire, among many others.
Parc Mine (lead & zinc), Aberconwy, Conwy, North Wales. Gilfach Mine (copper) Caernarfonshire, North Wales
Wednesday 16th September
Jurassic calamari: new research on fossil squid-like cephalopods from the Wessex Basin
Professor Malcolm Hart (Emeritus Professor, University of Plymouth)
Discoveries of some exquisite specimens of the soft parts of squid-like cephalopods have been found in the fossil record in the Wessex Basin. They are around 190–160 million years old; and there is exceptional preservation of eyes; ink sacks; beaks and arm hooks. Balancing organs, 'statoliths', of aragonite have also survived, and show internal (daily?) growth lines.
There are specimens of fossil squid-like cephalopods in the Natural History Museum (London), and Lyme Regis Museum; some collected by both Mary Anning and Henry De La Beche. When the GWR railway was built from Swindon to Bristol, local palaeontologist Joseph Pearce uncovered fossils at Christian Malford that caused great excitement, as soft parts of squid-like animals were preserved. The ink sacks and the muscle scars survived, and reconstruction of the creatures from the arms, some with pairs of hooks, could be attempted. A specimen from Bristol Museum & Art Gallery has non-paired hooks, so there is a potential for identifying species. Scattered statoliths have been recorded, but cannot be linked to a named species. It has been argued that the white discs with hooks could have been suckers, but it is difficult to understand that a sucker with a hook in its centre could function effectively. The Christian Malford beds were re-opened, in 2008, by the BGS, and a core from the 'squid bed' was found to have earbones, or 'statoliths', scattered throughout. There is a need to relate these to a species, so CT scanning of specimens from Christian Malford is taking place in the Natural History Museum to see if this can be achieved. Different shaped hooks are now thought to exist on the same animal, as one specimen from Germany shows five different kinds, and there are interesting questions on the evolution of the hooks that we see in the geological record.
An ichthyosaur specimen in the Etches Collection appears to show hooks as stomach contents, but it is possible that these may have fallen onto the specimen after death.
The exceptional preservation of material is exciting, and there is plenty more research to be done. Recently, new specimens have been found, and cleaned, clearly showing the arrangement of hooks in the arms. An old specimen, from the BGS collections, has been shown to record the capture, and presumed feeding, of a squid-like cephalopod holding a fish (Dorsetichthys bechei); one of the earliest records of cephalopod predation.
Wednesday 14th October
50 years of plate tectonics: past, current, and future, questions
Dr Marco Maffione (University of Birmingham)
The most unifying theory in Earth Sciences is that of Plate Tectonics, and it is one of the top five, most relevant, theories in the Sciences. Plate tectonics is the simple, and elegant, explanation of how our planet has been, is, and will be, shaped by the continuous movements and interactions of tectonic plates. I will guide you through the long journey of scientific discoveries that brought several scientists, with different backgrounds, to contribute to the birth of the plate tectonics theory; ultimately formulated just over 50 years ago. Since then we have understood much of how our planet works, which helped us. in the ‘90s, to reach a new, important, discovery on how our oceans expand. Today we still have several questions about key processes, such as the formation of new subduction zones, which represent new challenges for the current, and future, generations of Earth scientists.
Wednesday 21st October
From Coprolites to Cholera, the extraordinary life of William Buckland
Peter Lincoln (PhD Researcher, University of East Anglia)
William Buckland (1784-1856), Oxford’s first ‘Professor’ of geology, was a central figure of the ‘heroic’ foundational age of geological investigation. Buckland was a meticulous scientist and a devout, if sometimes rather too down-to-earth, clergyman. A charismatic lecturer, his flamboyant delivery stimulated his admirers, and scandalised his detractors, and, as a result, he was both venerated and vilified in life and, since his death, his eccentricities have often been more remembered than his achievements. However, Buckland’s foundational work in stratigraphy and palaeontology – his explanation of a hyena den at Kirkdale won him the Royal Society’s Copley Medal – and his early acceptance of glacial theory, put him firmly at the forefront of early nineteenth century geological endeavour. Equally at home with queens and quarrymen, William Buckland’s humanity shone through in everything he did. Appointed Dean of Westminster in 1845, he did not hesitate to use his new position to advocate scientific solutions to the problems of famine and disease. In this talk I shall aim to restore the memory of this geological hero by describing his long, and eventful, life, and outlining some of his many achievements, both in geology, and in the wider world.
Wednesday 18th November
The Jurassic Coast: the biggest story on Earth
Richard Edmonds (geologist and fossil collector, former Earth Science Manager for the Site; and the first warden of the Charmouth Heritage Coast Centre)
A look at the Dorset and East Devon coastal World Heritage Site;
185 million years of the Earth's geological history explored in the global context of plate tectonics, extinction events; and the evolutionary steps that eventually led to us.