Hertfordshire Geological Society

Identification and implications of the London Clay Formation divisions from an engineering perspective
2024-05-09 19:45 - 21:30 UTC | Oaklands College, Sapsed Room (SR), Oaklands College, St Albans, Hertfordshire, AL4 0XS, United Kingdom
Dr. Jamie Standing, Imperial College London
Abstract: Historically, engineers viewed the London Clay (LC) Formation as uniform, homogeneous and rather uninteresting. Chris King’s seminal work provided a much deeper insight into the characteristics of the LC and how it can be split into divisions, based on the depositional history of the formation and the microfauna present. LC water content profiles were compiled from continuous cores as part of an investigation into variations in tunnelling-induced settlements across St James’s Park, allowing distinct zones to be identified. These were found to coincide exactly with the divisions identified by Chris King almost twenty years earlier. Water content profiles can be developed as part of a ground investigation and used to help establish the boundaries between King’s divisions. Based on two further water content profiles from Hyde Park and St John’s Wood a new methodology for locating the boundaries of the divisions, involving a trend-line for sub-Division A3, is proposed and tested, relevant to conditions in central London. In developing the method, significant differences in the elevation of the divisions between the three sites is observed, suggesting geological processes such as folding or faulting have influenced the LC along the 5-km length of the section. Once the boundaries of the LC divisions are known, geotechnical engineers have a greatly improved overall understanding of the ground conditions and how the ground will respond to engineering works such as tunnelling and deep excavations. Broad engineering implications of the divisions are described and discussed, citing case histories where possible.
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Spying on open vent volcanoes from ground, air and space
2024-06-13 19:45 - 21:30 | over Zoom
Talk by Dr. Emma Nicholson (Liu), University College London
Abstract:
“Open vent” volcanoes are persistently active and maintain an unbroken connection between shallow magma reservoirs and the atmosphere. These volcanoes are true natural laboratories, providing an unparalleled window into the subsurface physical and chemical processes that control volcanic activity. Open vent volcanoes sustain large volcanic gas emissions and are therefore the “chimney pipes” of our planet, responsible for shaping the Earth’s atmosphere over geological time and impacting regional air and water quality on human timescales. Lava lakes are rare end-members in the expressions of open vent volcanism and can remain stable for years to decades. Yet, recent events at Kilauea (Hawaii), Ambrym (Vanuatu) and Nyiragongo (DRC) have emphasized how rapidly these lakes can drain to feed voluminous flank eruptions, posing substantial environmental and societal hazards. I will review some of the recent advances and outstanding questions in our understanding of the mechanisms and impacts of open vent volcanic activity. In particular, I will focus on how remote sensing observations—from the ground, air and space—combined with studies of erupted volcanic rocks are providing new perspectives on the long-term eruptive behaviour of open vent volcanoes. This talk will draw on new insights from a National Geographic expedition to one of the most remote active volcanoes on Earth – Mt Michael, located in the South Sandwich Islands at the gateway to the Southern Ocean.
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Painting with Stone: Materials, Methods and Traditions in Pietre Dure
2024-07-11 19:45 - 21:30 | Oaklands College, Sapsed Room (SR), Oaklands College, St Albans, Hertfordshire, AL4 0XS, United Kingdom
Talk by Dr. Ruth Siddall (University College London)
Abstract:
The talk will introduce the history, techniques and materials used in the decorative art of pietre dure (hard stone work). Almost every stately home and museum has a table-top or other object decorated with pietre dure and yet the craftmanship and materiality of the technique has been one of the most disregarded topics of study within the decorative arts. The technique of making patterns with coloured stones began in Antiquity and then found a renaissance in 15th Century Europe and was used equally for adorning large objects of furniture and small items such as stuff boxes and jewellery. The technique remained popular until the 19th Century in Europe and continues to be used in architecture and the decorative arts in Asia and particularly in India. The choice of stones used often has a specific connection to the workshops and therefore a knowledge of decorative stones used is essential for assigning a provenance to works made using the pietre dure technique.
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Modelling the Atmospheres of Tidally-locked Terrestrial Exoplanets
2024-09-12 19:30 - 21:30 | over Zoom
Talk by Dr. Andrew Rushby, Birkbeck College, University of London unfortunately had to be cancelled. We hope to reschedule the talk and include it in our 2025 programme.
Abstract
The climates of terrestrial planets are affected by their host star, the properties of their atmospheres, as well as any land, ocean, and icy surfaces, in predictable but also complex ways. I will provide a short introduction to the novel climatologies of tidally-locked (synchronously-rotating) planets in the orbit of small, cool M-Dwarf stars, highlighting recent ensemble and climate model intercomparison studies have been used to uncover some of the effects of the complex, ‘non-Earth-like’ rotational regimes of these worlds, which are likely common in our galaxy, on their possible climates and habitability by presenting some results from my recent work, as well as that of my students, collaborators, andcolleagues working in this area.
If time allows, I will also discuss the NASA ‘Research Coordination Network’ (RCN) model (of which NExSS was the first) and the means by which the astrobiology research and funding landscape within NASA, and beyond, is evolving to meet the needs of interdisciplinary scientists working in the field to leverage upcoming NASA, ESA, JAXA etc. missions, analogue studies, and observational platforms.
Bio – Dr Andrew Rushby is a Lecturer in Astrobiology and Programme Director of the MSc. Astrobiology programme in the School of Natural Sciences at Birkbeck, University of London.

Snowball Earth

The Geology of the Albert Memorial
2024-10-03 17:45 - 19:30 | Oaklands College, Sapsed Room (SR), Oaklands College, St Albans, Hertfordshire, AL4 0XS, United Kingdom
Talk by Professor John Cosgrove, Imperial College London.
Which will be followed by a visit to the Albert Memorial on Saturday 5 October 2024.

Unveiling the geology of Mars with robotic explorers
2024-11-14 19:30 - 21:30 | over Zoom
Talk by Dr Joe McNeil, Natural History Museum, London.
Abstract:
Before the first observations of Mars by orbiting spacecraft in the 1970s, it was widely thought that the red planet resembled Earth’s Moon in its geology. However, decades of robotic exploration by orbiters, landers, and rovers alike have radically reshaped our understanding, revealing Mars’ unique and complex geological history. Abundant evidence of past liquid water on its surface reveal processes both familiar from Earth and others that are entirely unique to Mars. In this talk, we will cover an overview of Mars’ geology, discuss how geological investigations of Mars are conducted from orbital and landed spacecraft, and explore the geological mysteries of Oxia Planum, the future landing site of the European Space Agency’s ‘Rosalind Franklin’ ExoMars Rover (launching in 2028).
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Perseverance examines martian geology

The Rutland Ichthyosaur: Digging up a 'Dragon’
2024-12-12 19:30 - 21:30 | over Zoom
Talk by Dr. Emma Nicholls, Oxford University Museum of Natural History
Abstract:
The full-scale excavation in 2021 uncovered the largest near-complete reptile
skeleton ever found in Britain. The animal nicknamed the ‘Rutland Sea Dragon’,
would have been around 10m long, in life, and is thought to be the first confirmed
record of its species, Temnodontosaurus trigonodont, found anywhere in the world
outside of Germany. In this lecture we will hear about the highs, lows, blood, sweat
and plaster, of the dig.
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More adventures in the Lambeth Group - how understanding stratigraphy helps engineering understanding
2025-01-09 19:30 - 21:00 | Zoom Talk
Desiccated Reading Formation clays around the London Underground Jubilee Line between Baker Street and Bond Street stations. Image is in the public domain at Bowers, Keith, and Neil Moss, 2018. “Investigation and reconstruction of a London Underground tunnel, UK.” Proceedings of the Institution of Civil Engineers-Civil Engineering. Vol. 171. No.

50th anniversary lecture by Dr. Jackie Skipper, Geotechnical Consulting Group & GSL William Smith Medal Winner.

Abstract:
The highly variable Paleocene Lambeth Group is today understood far better than even 25 years ago. Boreholes and engineering exposures for major civil engineering projects have provided clarification into how these sediments were formed, what engineering hazards they can cause and how we can manage these if we have a good understanding of the ground.
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Scotland’s Greatest Ice Age
2025-02-13 19:30 - 21:00 | Zoom Talk
Talk by Emeritus Professor Ian Fairchild, University of Birmingham
Abstract:
The Port Askaig Formation were the first Precambrian rocks interpreted as glacial in origin, anywhere in the world. Now we know that Neoproterozoic glaciation was global in distribution. The exposures of the Port Askaig Formation are also the best permanent exposures of glacigenic deposits of any age in the British Isles and have attracted much international interest. Over a decade of study by an interdisciplinary team have led to many new insights that will be presented in a Memoir of the Geological Society of London. There is an informal proposal that the base of the Cryogenian geological System should be located here on the Garvellach Islands of western Scotland.
Ian Fairchild’s contributions to Neoproterozoic geology have focused mainly on Svalbard and Greenland, as well as Scotland. In relation to the Port Askaig rocks he has sought to understand the association of dolomite with glacigenic facies and the significance of the glacial record both on the Garvellachs and the Isle of Islay.
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Epping Forest through geological time
2025-04-10 19:45 - 21:30 | Oaklands College, Sapsed Room (SR), Oaklands College, St Albans, Hertfordshire, AL4 0XS, United Kingdom
48th Percy Evans Lecture given by Mike Lambert, HGS Honorary President
As a child, Epping Forest was my playground, where I climbed trees, made dams and rode my bike. But there was one way in which it disappointed me. When I began collecting fossils and minerals and taking an interest in Geology, it seemed to have nothing to offer. Real Geology, so it seemed to me, only existed in places like Lyme Regis and Scotland.
This talk is my attempt to set the record straight and appreciate the many wonders that exist in and under Epping Forest. After describing the Epping Forest Ridge in its regional context, I’ll work my way up a stratigraphic column, from the oldest rocks of the Palaeozoic basement to the youngest superficial deposits. Along the way, we’ll examine discoveries made from roadworks in the 1970s, see how Anglian ice turned rivers back-to-front and visit a Neanderthal hunting and butchery site.
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Sea Level Change in the Anthropocene
2025-05-08 19:45 - 21:30 | Oaklands College, Sapsed Room (SR), Oaklands College, St Albans, Hertfordshire, AL4 0XS, United Kingdom
Talk by Dr. Colin Summerhayes, Emeritus Associate, Scott Polar Research Institute, University of Cambridge
Abstract:
Given the magnitude and rapid rise of greenhouses gases(including water vapour), their long lifetime in the atmosphere, and the present disequilibrium in Earth’s energy budget (expressed as the Earth’s Energy Imbalance, or EEI), both temperatures and sea level must continue to rise – even with carbon emissions lowered to net zero (where anthropogenic CO2 emissions = anthropogenic CO2 removals) – until the energy budget balance is eventually restored. Due to the natural lags between temperature rise, ice melt, and sea level rise, it will take a few centuries for this equilibrium point to be reached. There is a high probability that sea level rise will reach at least 1m (range 0.9-1.8m) above 1900 levels by 2100. During past warmer-than-present interglacials, sea level commonly reached between 4-9m above 1900 levels and occasionally between 12-15m above (much as in the warm periods of the mid-Miocene and mid-Pliocene).
Unfortunately due to technical problems this talk was not recorded.

Adventures of an Argon geochronologist: Why do we date rocks?
2025-06-12 19:30 - 21:30 | Oaklands College, Sapsed Room (SR), Oaklands College, St Albans, Hertfordshire, AL4 0XS, United Kingdom
Talk Dr Sarah Sherlock, Senior Research Fellow, The Open University
Abstract:
My current preoccupation is to find new ways in which we can increase the spatial resolution of Ar/Ar laserprobe dating to extract new information from rocks and minerals. Through this I, and colleagues, are investigating the diffusion mechanisms of argon in feldspars, understanding the behaviour of argon during friction melting, the uptake of excess argon in mudrocks and their attendant strain-fringes, the timing of fluid-rock interaction through dating authigenic alkali feldspars, dating meteorite impact craters, the behaviour of argon in volcanic glasses, and most recently in basalts. Recent work in Turkey provides examples of the use of Ar39/Ar40 dating techniques and how they can be used in the geological interpretation of regional igneous and tectonic provinces.

Thames Through Time - with a Cornish flavour
2025-07-10 19:45 - 21:30 | Oaklands College, Sapsed Room (SR), Oaklands College, St Albans, Hertfordshire, AL4 0XS, United Kingdom
Talk by Ian Mercer from the Essex Rock & Mineral Society.
Abstract:
Ian Mercer reveals the story of the Thames across Essex by digging into the landscape in and around the county. The Thames has changed course dramatically and repeatedly throughout the past two million years of the current ice age. The greatest impact of the Thames upon the landscape is during times of cold, when Spring thaws create mighty torrents of water. River-bed gravels have been deposited while the land has been tilting gradually throughout this time, resulting in ‘staircases’ of gravel terraces across the landscape and beneath the temporary flood of the North Sea.
During this time, the rivers have brought rocks from across the area of southern Britain as evidence of their journeys. These include beautiful black-and-white pneumatolytic quartz-tourmalinite from around the granite intrusions of the South-West. Ian has collected many of these from across Essex and East Anglia and has grown to love them. He reveals their evidence in the land and in church walls. The Thames will change again many times as climate continues to oscillate.

Update on Icelandic volcanism
2025-09-11 19:45 - 21:30 | Oaklands College, Sapsed Room (SR), Oaklands College, St Albans, Hertfordshire, AL4 0XS, United Kingdom
Talk by Emeritus Professor Hazel Rymer, The Open University
Abstract
Volcanism on Iceland is both a source of geothermal & tourism revenue but also a hazard. Geophysical data can be used to explore the origin of the island of Iceland, the ongoing volcanic activity and to predict its future. Here we’ll look at the latest news and measurements from the land of ice and fire.

Angiosperms: pollen, evolution and ecosystems
2025-10-09 19:45 - 21:30 | Oaklands College, Sapsed Room (SR), Oaklands College, St Albans, Hertfordshire, AL4 0XS, United Kingdom
Talk by Dr Luke Mander, Senior Lecturer, The Open University
Abstract
Luke’s works with both living plants and material from the plant fossil record, which represents a vast archive of morphological novelties and natural design solutions that have been produced over the course of evolutionary time. In this context, he is particularly interested in the evolution of tropical rainforests, which are among the most complex ecosytems on Earth. He has worked mostly with pollen grains, which are morphologically fascinating objects with an outstanding fossil record, but also work with the leaves of vascular plants.
His current research activities are focused on plant palaeobiology and morphology.
He is interested in quantifying the morphology of plants, classifying plants on thebasis of their morphological characteristics, and investigating the biogeographical evolution of plant diversity.
Biography
Luke received a PhD in 2010 from University College Dublin for a thesis that investigated 200 million-year-old fossil plant remains in East Greenland. He then spent two years as a postdoc in the Department of Plant Biology at the University of Illinois, Urbana-Champaign. I returned to the UK with a two-year EU Marie Curie fellowship in the Earth System Science group at the University of Exeter. He has been a lecturer at The Open University since 2015.
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The Onset of Modern-Style Plate Tectonic
2025-11-13 19:30 - 21:00 | Zoom Talk
Talk by Professor Craig Storey, University of Portsmouth
Abstract
Since the 1960s we have accepted the plate tectonic paradigm as being central to how our planet operates at the present day. However, there is much ongoing debate as to when plate tectonics began and how similar it was to the current observable mode. Hypotheses range from the Hadean to the Neoproterozoic and therefore span across profound changes in the Earth system, including atmospheric oxygenation and the proliferation of life. In this talk I will review (some of) the “hallmarks” of plate tectonics, their first appearance and secular evolution, and speculate on when it all began and how it evolved.
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The value & potential of the UK’s dinosaur track sites
2025-12-11 19:30 - 21:00 | Zoom Talk
Talk by Richard Butler, Professor of Palaeobiology, School of Geography, Earth and Environmental Sciences, University of Birmingham
Due to unforeseen circumstances Richard was unable to give this talk so it will be rescheduled to a future date.
Abstract:
Dinosaur tracks provide important data on the distribution of dinosaurs through time and space and unique information on palaeobiology and behaviour, such as dinosaur locomotion, herding behaviour and species interactions. Dinosaur tracks and trackways are typically not collected and generally are left in the field: as such they have significant realised and potential value for tourism and education. In our recent work, we have comprehensively reviewed the distribution of dinosaur track sites in the UK and their scientific and cultural ‘value’. Fourteen dinosaur track sites are present in situ in the UK today, distributed across England, Wales and Scotland, and spanning from the Late Triassic to the Early Cretaceous. UK sites with considerable national and international scientific value include the Late Triassic dinosaur track site Bendrick Rock, in South Wales, and the Middle Jurassic site at Ardley and Dewars Farm quarries in Oxfordshire, parts of the latter having been excavated by our research team in 2024 and 2025. By contrast, the Early Cretaceous dinosaur track sites at Hanover Point, Isle of Wight, and Spyway Quarry, Dorset have relatively high cultural value due to their accessibility and visitor appeal, but modest scientific value. Our work helps identify threats and opportunities for UK dinosaur track sites, potentially helping to guide future conservation, scientific research, and public engagement efforts.

Stratigraphy & Sedimentology of Northern European Chalks
2026-01-08 19:30 - 21:00 | over Zoom
given by Dr Haydon Bailey, HGS Chairman, Past GA president & geological advisor to the Chiltern Society
Abstract:

The Upper Cretaceous Chalks of Northern Europe appear, on the face of it, to represent sedimentation during an extended period of relative tectonic and environmental stability. Nothing could be further from the truth. These uniform, white, fine grained carbonates are the sediments resulting from constant change in water temperature, oxygen content, dynamic water currents both at the sea surface and at depth.
Back in 1994 I presented a talk at a European conference entitled “Chalk, white, as above!”, because that was the comment frequently seen on core logs, geologists’ description sheets and engineering geologists’ well logs. Just how much information were we losing because of this phrase? Over the last 30 years our understanding of chalk deposition, and the environmental conditions which control it, have fundamentally shifted. Hopefully I can convince you that this might be the case.
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This replaced the scheduled talk on Critical Minerals from Geology to circular economy: A matter of national security planned to be given by Professor Kathryn Moore, University of Exeter. This was due to bad weather. Kathryn’s talk will be rescheduled to a later date.

Critical minerals from geology to circular economy: a matter of national security
2026-01-08 19:30 - 21:30 | over Zoom
talk given by Associate Professor Kathryn Moore, University of Exeter
Abstract:
With the imminent release of a new Critical Minerals Strategy, the UK is updating its approach to national security. In this lecture, I will highlight the security issues that threaten critical mineral supply chains into the UK and into most countries. I will explain how mitigation of the risks requires ground – truthing, based on an understanding of geology and material properties, as well as wider socioenvironmental and political considerations. I will discuss how the needs of critical minerals production is a challenge in terms of skills requirement, and why the discipline of geology has never been more important.
Unfortunately this talk had to be cancelled due to communication issues caused by Storm Goretti. The talk will be rescheduled for a later date.

The end-Triassic mass extinction and its aftermath
2026-02-12 19:30 - 21:30 | over Zoom
talk given by Professor Paul WIgnall, University of Leeds

49th Percy Evans Lecture: The Geology of the Lower Chess Valley & where does all that water go?
2026-04-09 19:45 - 21:45 | Redbourne Parish Centre, The Park, Redbourne, Hertfordshire, AL3 7LR, United Kingdom
given by Dr. Haydon Bailey, HGS Chairman

Geology of Stonehenge and the bluestone controversy
2026-05-14 19:45 - 21:45 | Redbourne Parish Centre, The Park, Redbourne, Hertfordshire, AL3 7LR, United Kingdom
talk given by Prof. Peter Worsley, Emeritus Professor of Quaternary Geology, University of Reading

The Chalk Sea Ecosystem Project
2026-06-11 19:45 - 21:45 | Redbourne Parish Centre, The Park, Redbourne, Hertfordshire, AL3 7LR, United Kingdom
talk given by Dr James Witts, Senior Post Doctoral Researcher, Natural History Museum London

Researching the Puddingstone Book
2026-07-09 21:45 | Redbourne Parish Centre, The Park, Redbourne, Hertfordshire, AL3 7LR, United Kingdom
talk given by Gerald Lucy, Essex Rock & Mineral Society & Mike Howgate, AGS & HGS

The Deep Geology beneath southern England (TBC)
2026-09-10 21:45 | Redbourne Parish Centre, The Park, Redbourne, Hertfordshire, AL3 7LR, United Kingdom
talk given by Dr. Chris Pullen, Director, CP Exploration

Book Presentation - The Meteorites
2026-10-08 19:45 - 21:45 | Redbourne Parish Centre, The Park, Redbourne, Hertfordshire, AL3 7LR, United Kingdom
given by Helen Gordon, Hertfordshire University & Author

Alpine peaks and salt intrusions - Geological windows into Earth's mantle
2026-11-12 19:45 - 21:45 | over Zoom
given by Dr. Jonathan Turner, Geologists’ Association Field Guide Editor

The history of geological thought and exploration of the geology of the Himalaya
2026-12-10 19:45 - 21:45 | over Zoom
given by Dr. Danny Clarke-Lowes, Director, Nubian Consulting
