West Sussex Geological Society

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Jonathan Gammon
The nature of the varying ground conditions and groundwater regime beneath London presents a wide range of challenges to the formation of railway tunnels and the construction of underground stations. Introducing the geology of the London Basin and its key geological formations that are encountered beneath the ground surface. Advances in technology, initiated by Marc and I.K. Brunel, adopted to form tunnels and tackle the challenges presented by London’s geology are explained and illustrated. Such advances have been a major factor in the expansion of the network of underground railways in London. A more-detailed description of different techniques to form underground space, including cut-and-cover (“green”) tunnels, mined tunnels using Sprayed Concrete Lining, and bored tunnels using Tunnel Boring Machines (TBMs) of varying types, specifically to Crossrail (now the Elizabeth Line) and to the Northern Line Extension, between Kennington and Battersea Power Station.

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Nick O'Riordan
The talk examines the ground and, to an extent, societal conditions in Florence and San Francisco and the effects they have had on the design and construction of long, wide and deep high speed rail station boxes. In Florence, the most important effects were in the prediction of future groundwater flow regimes, the avoidance of flooding and aseismic design. In San Francisco, the main challenges were in the construction of the box in a dense, high-rise urban fabric in an active earthquake zone. Both cases involved the characterisation of soils (Firenze 4 and Old Bay Clay) that had not been 'disturbed' by complex engineering before.

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James Witts
This talk will showcase work from the ChaSE project. As an economically important resource, the UK Chalk Group has been studied and quarried for over 200 years and a detailed stratigraphic framework is available. The chalk is often abundantly fossiliferous, recording every marine trophic level from phytoplankton to apex predators. Key events recorded in the Chalk include a dramatic period of environmental change and biodiversity crisis at 93.9 million years ago. This includes the global carbon cycle perturbation, rapid changes in seawater oxygenation & temperature, and sea level fluctuations. The UK Chalk provides important evidence for the complex response, and resilience, of marine ecosystems to rapid climate change in the “greenhouse” world of the Late Cretaceous.

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Peter Webster
More than just Rock: Geology is the secret ingredient to the scenery, history , wildlife, industry and much more.
A lighthearted look at the landscape's hidden foundations.
Photos will be numerous and backed up with an amusing anecdotal talk.
This is a reprise of a recent talk given by Peter to the HGFC.
It will cover of most of the locations that the WSGS will be visiting in our upcoming away field trip in July.

Dr Robert Chandler FGS
The talk is a summary of the methods, fieldwork and objectives of Ammonite Biostratigraphy, highlighting both the current advances and the limitations of the methods using international comparisons and focussing on the local Inferior Oolite Formation of Dorset.

Dr Colin Brough
Marcasite is one of the polymorphs of iron sulphide, the other being Pyrite. It forms in spectacular twinned crystals that look like spear heads. Why such crystals form in the chalk as Shakespeare cliff (and in similar locations across the channel, has always been a challenge to explain. This talk will look at the geological setting, the geochemistry of the chalk at the time of formation and how this relates to the deposition of Marcasite, rather than the more stable form, Pyrite. Lastly we will look at some of the challenges extracting the crystals from the chalk and the challenge of limiting their decay once removed.

Alex Jones
The red planet is now a barren desert landscape, cold and inhospitable for life. But the surface of the Mars is covered in evidence for ancient rivers, floods and lakes, suggesting the planet may have been warmer, wetter and more pleasant for life in the distant past. In this talk, Alex Jones, a student collaborator on the NASA Perseverance rover mission, will take us on a fieldtrip to Jezero crater – the site of an ancient Martian lake-bed, showing how the rover's exploration of the stratigraphy preserved here, is shedding light on Mars' ancient surface processes and habitability.

Nigel Hoad
A journey through the groundwater resources of Namibia will introduce the geological framework of the country and the hydrogeology based upon this framework.
The methods and approach to locate viable, potable supplies of groundwater shall be described.
The talk will describe drilling methods, then go to describe groundwater management procedures.
This professional experience will be concluded with personal impressions.

David Bone
Widely used in jewellery, Amber originates in Eocene forests that formerly covered the Baltic area.
The talk will look at its geology, collecting history, and exceptional use that was looted in World War II.