Geology of Stonehenge and the bluestone controversy
2026-05-14 19:45 - 21:45 UTC | 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
Abstract
Stonehenge has recently come into the public eye due to the publication of the results of new geochemical work. The Sun newspaper declared ‘Mystery of where the giant rocks came from SOLVED’ whereas The Guardian was more cautious with a headline ‘Archaeologists discover likely source of Stonehenge’s giant sarsen stones’. The senior English Heritage properties historian said that she was delighted that one of the most intriguing questions about Stonehenge had been answered. The background to this ill-judged euphoria will be critically examined and the geological fundamentals reviewed.
Apart from the sarsens, the other geological problem lies with the assemblage of ‘foreign’ rocks incorporated into the henge structure, i.e. the so-called Bluestones. There now appears to be little doubt that the Bluestones are primarily derived from outcrops in south-west Wales but the mechanism whereby they arrived to Salisbury Plain are far from being resolved. Most archaeologists have accepted the hypothesis that Neolithic people were responsible for the transport of the lithostats from their source to the plain but over time the favoured routes have changed drastically. In contrast geologists have been split between those who accept the human transport mode and those who favour natural earth surface processes as being responsible for transportation – glaciation. The strengths and weaknesses of these competing ideas will be assessed.

ChaSE-ing the chalk: the Chalk Sea Ecosystems project and Late Cretaceous
2026-06-11 19:45 - 21:45 | Redbourne Parish Centre, The Park, Redbourne, Hertfordshire, AL3 7LR, United Kingdom
talk given by Dr James Witts, NERC Postdoctoral Fellow in Palaeoecology, Natural History Museum, London
Abstract:
The onshore Chalk Group of the United Kingdom provides a continuous and well-exposed rock and fossil record spanning the Late Cretaceous (Cenomanian –Maastrichtian stages, ~100 – 72 Ma). As an economically important resource, the chalk has been quarried and studied for >200 years and a detailed stratigraphic framework is available. The sequence is abundantly fossiliferous, recording every marine trophic level from nanno- and phytoplankton to benthic and nektonic molluscs and apex predators. Key events recorded in the Chalk include carbon cycle perturbations during the middle Cenomanian and across the Cenomanian – Turonian boundary (Oceanic Anoxic Event 2 – also associated with peak Cretaceous climate warming and a biodiversity crisis), the highest global sea-levels of the last 250 myrs during the Turonian, and a long-term climate cooling which culminates with the coldest temperatures of the Late Cretaceous during the Maastrichtian.
The Natural History Museum, London (NHMUK) alone contains >55,000 UK Chalk Group macrofossil specimens, including rare taxa and material from now inaccessible localities. Only a fraction of these have been published or are available in public datasets. Many specimens contain limited metadata, and ages or stratigraphic position are poorly constrained. To unlock these ‘dark data‘ we are re-dating >1,500 macrofossil specimens using calcareous nannofossil biostratigraphy. Combining these with data from new fieldwork, we are conducting the first ‘whole-ecosystem‘ study of the functional diversity and ecology of the Chalk Sea, providing an unprecedented record of the effects of global Cretaceous climate change on marine ecosystems at a variety of temporal and spatial scales, all within the same depositional system.
Biography:
I trained as a geologist with an MEarthSci degree from the University of Manchester (2009), completing a PhD on the Cretaceous-Paleogene (K-Pg) mass extinction event in Antarctica with the University of Leeds and British Antarctic Survey in 2016. I then hopped ‘across the pond’ for a Lerner-Gray Postdoctoral Research Fellowship at the American Museum of Natural History in New York (2016-2018) and a postdoctoral position at the University of New Mexico in Albuquerque (2018-2020), studying Cretaceous and Paleogene macrofossils and ecosystems in the US Gulf Coast and Western Interior. After a stint as Lecturer in Palaeontology at the University of Bristol (2021-2023), I moved to the NHM as a NERC Postdoctoral Fellow in Palaeoecology in September 2023.

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
