Tuesday 13th June.  8.00pm. Face to Face talk at Finchley Baptist Church with examples of this technique.

“Painting with Stone: Materials used in Pietre Dure and Related Lapidary Work”

Dr. Ruth Siddell BSc.  UCL Student Mediator, UCL Gower St. London WC1

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 stone is essential for assigning a provenance to works in pietre dure.

Ruth is very well known for her guided ‘Building Stones’ walks in London and also educational guides to ‘Urban geology’.  Please see her UCL homepage for more information.  Ruth is actively involved in teaching both practical and theoretical techniques in applied mineralogy and petrology.  These techniques are used in the identification of components in archaeological and historical materials via postgraduate courses at UCL, UCL Qatar, University of Glasgow and the British School at Athens.


Tuesday 11th July    8.00pm  Face to face talk at Finchley Baptist Church

“We will be looking at the south coast from the Isle of Wight westwards along to Devon.  Examining the structures and pictures from the air to understand how the coastline of this attractive and geologically interesting part of the UK was formed.”  

Stephen Krause Bsc. of the AGS

Tuesday  8th August. 8.00pm at Finchley Baptist Church


No ‘Golden Egg’ competition this year but a variety of things going on thus:

It will be a ‘Conversazione’ style evening with a theme ‘Hertfordshire Pudding Stone’.

There will be Mini-Presentations on:

” The Cretes of Hertfordshire ” by Mike Howgate (AGS)

“Discovering Essex puddingstone” by Gerald Lucy (ERMS)

“How to use a puddingstone quern” by Chris Green (HGS)

There will be displays of spectacular puddingstone by invited guests and members.  FREE to AGS members and £5 visitors and guests in advance through Mike Howgate at


In addition, members are invited to bring along their ‘Favourite Specimen’ from their collection with their name and where it was found or purchased and state why it is their favourite, or why it is significant to them. These can be discussed and admired during the evening. Members are also invited to bring along up to five items they would like identified. ie. rocks, fossils, minerals etc from their collections. There will also be a table of fossils, rocks and minerals for sale to raise funds for the AGS.  There will also be free wine and nibbles……..

Tuesday 12th September – 8.00pm. Face to face talk at Finchley Baptist Church

“Meteorite Impact Craters and the Geological Record”

Dr. Aurial Rae Research Fellow at Trinity College Cambridge.

Impact Cratering is an important planetary and geological process, affecting the surface of almost all planets and satellites in the solar system. Studying impact cratering is challenging because the Earth’s impact record has been severely affected by other geological processes and impact structures on other planets can only realistically be studied by remote sensing techniques. Furthermore, all of the processes in an impact cratering event cannot be simultaneously reproduced by experiments in the laboratory.

My work combines observational and experimental methods with numerical modelling to understand the highly dynamic processes associated with impacts. More specifically, in recent years, my research has focussed on dynamic rock failure, complex crater formation, and shock metamorphism.

Tuesday 10th October – 8.00pm. Face to face talk at Finchley Baptist Church

“Medieval Cambridge and the Glacial Erratics of East Anglia”

Prof. Marian Holness & Prof. Philip Gibbardis of University of Cambridge.

Building stones offer a window into the past: what stone was used for each project and why? A notable example with a fascinating story behind it is what is known as “field stone”. This is used for the most ancient buildings in Cambridge and comprises cobbles and fragments of stone cleared from fields during ploughing. This material was used for buildings and roads up to the arrival of the Black Death in the late 1340’s. The cobbles used to build churches include a huge range of different rock types, whereas those used to build roads are dominated by hard rocks such as basalt, granite and high-grade metamorphic rocks. One particular rock type stands out  – this is an extrusive igneous rock characterised by large crystals of feldspar, known as a rhomb porphyry, with a known source in the Oslo region of Norway. In this talk, we will explain how these rocks were brought to the Cambridge region during the recent Ice Ages, by glaciers flowing from Scotland and Scandinavia.


Marian Holness is Professor of Petrology at the University of Cambridge, and a Fellow of Trinity College. She obtained both her BA and her PhD from Cambridge, with an intervening short stint at the University of Chicago. She is interested in the physical behaviour of solidifying bodies of magma, and decodes the history of igneous intrusions using a combination of chemical and microstructural observations.


Philip Gibbardis Emeritus Professor of Quaternary Palaeoenvironments in the University of Cambridge, England, and Adjunct Professor in the University of Helsinki, Finland.  He took his BSc degree in Geology at the University of Sheffield in 1971 and his PhD in the Subdepartment of Quaternary Research, University of Cambridge in 1975. He is currently Secretary General of the International Commission on Stratigraphy and a member of the Geological Society of London’s Stratigraphy Commission. His research is focused on Quaternary and late Tertiary terrestrial and shallow marine sedimentation, stratigraphy and palaeoenvironmental reconstruction throughout Europe. 


Panorama of King’s Parade – Cambridge.                                 Rolf Sussbrich                                         https://creativecommons.org/licenses/by-sa/3.0

Tuesday 14th November – 8.00pm. FIRST ZOOM MEETING of winter 2023


“Minerals of the English Midlands”

Roy Starkey BSc.  Lapworth Museum (University of Birmingham)

The mineral wealth of the English Midlands has been exploited for centuries – lead, copper, zinc, and to a lesser extent silver, have all been worked. Deposits of coal, iron ore and limestone powered the Industrial Revolution, providing the raw materials for such visionaries as Sir Richard Arkwright, Matthew Boulton, James Watt, William Murdoch and Josiah Wedgwood.

The area has produced a wide range of interesting mineral specimens. Examples of these are to be found in local and regional museum collections, and especially at the Natural History Museum in London. However, such was the importance of Britain in the development of mineralogy as a science that specimens from the English Midlands are to be seen in collections all over the world.

Minerals such as phosgenite, matlockite and mottramite are recognised as having been first described from the English Midlands. Although the glory days of mining are long gone, quarrying operations, especially in Derbyshire, Gloucestershire, Leicestershire and Shropshire mean that fresh exposures are constantly being created, and new mineralogical discoveries continue to be made today.

The area has also produced a variety of decorative stones such as Blue John, alabaster and Ashford Black Marble and these too will be examined.

Thanks to the efforts of miners, mineral dealers and collectors over the past few hundred years, interesting and beautiful specimens have been preserved for us to enjoy today. This talk will provide an overview of the fascinating stories associated with the mines, quarries and minerals, illustrated by images taken especially for a recently published book Minerals of the English Midlands.

Roy Starkey is a regular speaker on the British mineralogical / geological society circuit. He graduated from Sheffield University with a BSc(Hons) in Geology in 1974, and has a pursued a career in manufacturing and operations management, gaining experience in a wide variety of engineering and technology product sectors, including ten years with Morgan Crucible manufacturing technical ceramics (crushed high-purity rocks!). He is now retired and seeks to devote more time to his mineralogical interests.

He founded the British Micromount Society (http://britishmicromountsociety.homestead.com/) in 1981, and has held a variety of roles in the Russell Society ( http://www.russellsoc.org/ ), the UK’s leading society for amateur and professional mineralogists, and is a former President, and the current General Secretary.

Roy has published widely on British topographical mineralogy, including papers in the Mineralogical Magazine, Scottish Journal of Geology, Proceedings of the Geologists’ Association, Proceedings of the Bristol Naturalists Society, the Mineralogical Record, and the Journal of the Russell Society. He completed a major article for the Mineralogical Record on Herodsfoot mine, Lanreath, Cornwall, which was published in 2012.

Roy has worked as a part-time volunteer curator at the Lapworth Museum (University of Birmingham) – since 2010 http://www.birmingham.ac.uk/facilities/lapworth-museum/index.aspx

He served as a member of the Project Team, and Project Board, for the recent HLF-funded redevelopment of the Lapworth Museum, and was nominated as the recipient of the prestigious Marsh Award for Mineralogy 2016 https://blog.nhm.ac.uk/2017/02/21/roy-starkey-wins-first-marsh-award-for-mineralogy/ “in recognition of his scientific contributions and public promotion of Mineralogy in the United Kingdom”.

Roy’s research interests are in the areas of British topographical mineralogy, the history of mineralogy, and the mineralogy of Scotland in particular. He published his first book – Crystal Mountains – Minerals of the Cairngorms, in September 2014; and followed this with Minerals of the English Midlands in September 2018. He has just published his third book, a major biography of the famous British mineralogist Sir Arthur Russell (see https://britishmineralogy.com/wordpress/ ).


Photos: copyright Roy Starkey BSc.

Tuesday 12th December – 8.00pm. Zoom meeting



October 8th – 8.00pm. Face to Face meeting at Finchley Baptist Church

Prof. Marian Holness Cambridge University 

“Layered Intrusions”

Previous Talks

Tuesday 9th May  8.00pm   

AGS Annual General Meeting at Finchley Baptist Church

AGM + free wine and nibbles.  FREE 25 page Booklet on the Ashdon Meteorite Event (worth £5) for those who attend.  AGS paid up members members only!

Tuesday 11th April.

First face to face talk of 2023 with the return to Finchley Baptist Church.  8.00pm.

“Pipelines across Turkey”

This will be our 12th talk by Tony Waltham – Engineering geologist and karst specialist.

Following the pipelines that carry oil and gas from the Caspian to the Mediterranean provides the opportunity to take in some of the geological highlights and spectacular landscapes of Turkey, Georgia and Azerbaijan. The Obruk Plateau, the Sivas gypsum karst and the towers of Cappadocia lie down the line in Turkey, while the mud volcanoes are among the exciting features of the Caspian oilfields.

Tony Waltham is an engineering geologist and karst specialist, a lecturer, author and travel guide.  He is the owner of the Geophotos picture library and editor of Mercian Geologist.  He is also a member of the editorial board of Geology Today, to which the AGS subscribes, and you will always see one of his super photographs on the outside back cover, with his explanatory text.  His talks are hugely popular, and we are most fortunate that he is willing to come every year to talk to our members, despite the long journey from Nottingham.  This will be his 12th talk to the AGS and he will always get a warm welcome from our society.

Lecture Turkey pipelines P7910A
Lecture Turkey pipelines R081086

Tuesday March 14th 2023 


An illustrated Zoom talk by Professor Gerald Roberts of Birkbeck College, London. 

Gerald did a BSc Geology at Cardiff (1984-1987), a PhD in Durham (1987-1990), a NERC Fellowship at University of Manchester 1990-1992, and then became a lecturer at Birkbeck in 1992. Staying at Birkbeck throughout my teaching and research career, I became a Professor of Earthquake Geology at Birkbeck in 2012, and Head of Department (2012-2018) just after that. I am a NERC core panel member. I have ~100 papers mainly on active faulting and earthquake hazard.

“My talk will be on ‘Active faults and earthquake hazard’, mainly concentrating on Italy. I will show damage and surface faulting associated with the 2016 Amatrice-Norcia earthquakes (Mw 6.2-6.6). I will talk about we should communicate hazard to populations based on understanding of how faults slip over long time periods including many earthquake cycles. I will show the results from 36Cl cosmogenic dating of fault scarps which constrain earthquake recurrence over 10-20 millennia and tens of earthquake cycles. I will show that earthquakes cluster in time which makes it challenging to communicate the complexity of earthquake recurrence to at risk populations.”

PastedGraphic-1Surface faulting produced by the 2016 Mw 6.6 Norcia earthquake in central Italy.

Tuesday February 14th 2023   

“The Himalayas”

An illustrated zoom talk by Chris Darmon, editor of ‘Down to Earth Magazine’ and Colin Schofield, assistant editor.

Nobody, least of all the pioneer climbers, expected the highest point on planet Earth to be made of sedimentary rock and what’s more, it was fossiliferous! Back in 1953 when Hilary was conquering the summit of Everest, plate tectonics was in its infancy and how rocks reached high altitudes was one of the many things that was not really understood.

Chris tells the tectonic story of the Himalayas and then goes on to explore the rocks that make up the mountains that form the ‘roof of the world’.

Chris is a qualified geologist from Hull University, who over many years has taught geology to comprehensive school students, adult evening classes, WEA and University of Sheffield students.  Following retirement, he founded ‘Geo Supplies Ltd.’ as a leading international supplier of geological books, maps and equipment and of course Down to Earth Magazine.  He also set up his own popular residential and day field courses, which continues to this day, alongside residential face to face courses both at home and overseas.  Since covid, Chris has seized the opportunity of delivering learning via zoom and despite being past retirement age, he continues to greatly enjoy teaching adults who really want to learn about geology at all levels.

Screenshot 2023-02-01 at 14.55.10

Tuesday January 10th 2023  

An illustrated Zoom talk by Ros Mercer from the Essex Rock & Mineral Society

“Volcanoes Past and Present”.

We start by looking at some recent volcanic eruptions and then we tour the UK looking at the remains of past eruptions, with recent interpretations of their eruption type and their relationship to the plate tectonics of the time. This enables them to be compared to modern analogues. From Leicester Forest to Snowdonia, the Lake District and Edinburgh, there are many past volcanoes hidden in our scenery.

Ros is a qualified geologist and secretary of the Essex Rock & Mineral Society, plus has worked at the BGS, in the UK offshore oil and gas industry and in her time has also taught geology and physics!  Now retired, she ‘wanders ‘around with her husband Ian, also a geologist, looking at pebbles, crystals, volcanoes and gems!

Tuesday December 13th 2022   Zoom presentation. 

“Crinoids in the national news”: Preliminary observations and implications of a new Bathonian (Middle Jurassic) lagerstätte in Wiltshire, UK.

An illustrated Zoom talk from Dr. Tim Ewin Bsc. of the Natural History Museum.

A new UK Bathonian (Middle Jurassic) lagerstätte has revealed one of the most important Jurassic echinoderm localities in the world. Excavation of the site has produced thousands of exceptionally preserved articulated echinoderms including at least 18 species, belonging to all five extant echinoderm classes. Fossilised purple crinoid pigment has also been found at the site. Other significant fossils include plants and Radiolaria, the latter being rarely seen in UK onshore Jurassic rocks. The fossils are preserved in various orientations, indicating brief transportation prior to rapid burial (obrution) whilst other, more disarticulated, shelly fauna suggest greater transportation prior to burial. The echinoderm fossils are dominated by the true comatulid crinoidAndymetra sp., represented by over 3000 individuals, and the stalked crinoid Isocrinus sp. This is the earliest incidence of true comatulid crinoids dominating a sea floor environment. It is significant as “comatulid meadows”, important areas of biomass and diversity in several modern soft sea floor ecosystems (such as at continental shelf margins), are unknown in the fossil record before the Cretaceous.”

CV: Dr Timothy A. M. Ewin

2000-2004 – PhD in Palaeobiology, University of Manchester, (Mesozoic conifer foliage characterisation)

2005-2008 – Curator of Geology, Bristol City Museum and Art Gallery

2008-present – Curator of Invertebrate Palaeobiology (Echinoderms), currently Senior Curator.”

Biography: I am a passionate natural history curator and palaeontologist with over 15 years’ experience working within internationally renowned museums. I am a senior curator at The Natural History Museum, primarily responsible for the world class fossil Echinoderm collections (starfish and their relatives). My role ensures the collections are cared for, made readily accessible for study, exhibition and outreach and, that new important finds are ethically acquired. My research primarily focuses on past echinoderm diversity and palaeoecology and I have published over 28 papers in internationally recognised science journals and presented my science at numerous international conferences. I have also written chapters for and edited guidebooks on British fossils and produced a smartphone app to aid identification of UK fossils. I have travelled widely, undertaking fieldwork in places from the deserts of the USA and Morocco, to the grasslands of Russia and windswept coasts and quarries of England.

 Imagined Permian sea floor with crinoids – Richard Furminger


Frank Stokes Memorial Lecture

Tuesday 8th November 2022 7.45pm for 8.00pm start. Zoom meeting.

“Rocks in Thin Sections” by Barry J. Hunt of IBIS Ltd.

“There is a long and not necessarily complete history to the process of thin-sectioning materials for microscopical examination.  With respect to examining rocks the first thin-sections may have been prepared as early as 1814, but it was Henry Clifton Sorby in the 1840s who established a procedure for preparing rocks in a way that allowed the investigation of mineral composition and rock structure. 


The use of thin-sections for the examination of rocks today remains the cornerstone of geological investigations.  It is a procedure that provides the most information from a rock sample and it has been adapted for looking at many other materials such as concrete, cement, plaster, render, mortar and anything else comprising both crystalline and glassy phases.


I will take you through the basics of the preparation of thin-sections, how to get the best out of them, and then the different optical procedures that may be applied to assist the recognition of minerals, fabrics and textures.  I will employ a range of different rocks and materials to demonstrate the great variety of colours and textures that make different materials so unique.  I will explain the many pros of the methodology as well as the cons, the latter being relatively few.  A few examples of where petrography has proven the key to understanding major problems will also be given.


Welcome to my microscopic world of wonder, where I now have several thousand thin-sections representing the last 20 years of work I have carried out in this field.  It is an area of amazement where even concrete can be interesting.”


Barry Hunt is chartered as a geologist, surveyor, scientist and builder. He has been awarded the designation of European Geologist. Barry is also a Fellow of the Royal Microscopical Society. He has been a member of a number of professional committees and has published numerous papers and articles concerning some of the findings of his many investigations.  In 2001 he formed his own company, IBIS, specialising in the investigation of all construction materials. The specialist knowledge obtained and services provided have allowed him to be instrumental in the resolution of problems ranging from blast damaged claddings in London’s West End to advice on the quarrying and extraction of stone from abroad for import to the UK. 

Barry is probably one of the most experienced building surveyors in the UK when it comes to both historic and modern façades. He regularly undertakes condition surveys for major buildings, and regularly looks after the fabric of the Bank of England which has a number of unusual challenges.  He strongly believes that close hands-on surveying is the only way to survey natural stone façades to fully understand the issues that may be present.  As well as writing many articles for publication he also believes it is important to spread the findings of his many investigations. He has given many different talks on different aspects of the work he has carried out, often trying to raise awareness of critical issues such as maintaining the safety of natural stone in construction. Barry has also been both a mentor and scrutineer for the Geological Society to assist younger geologists into the professional sphere.

Tuesday 11th October 2022     7.45pm for 8.00pm start

The last Face to Face meeting in Finchley Baptist Church this year.

‘The Geology of the Cape Verde Islands’ by Professor HILARY DOWNES from Birkbeck University of London

“The Cape Verdes archipelago is a series of volcanic islands off the coast of West Africa. Eruptions have occurred in historic times, including one as recently as 2015. The Cape Verdes are only one of two groups of oceanic islands in which igneous carbonatite rocks have been found.  Our research in the area has focussed on volcanic collapse, the hazards associated with different styles of volcanic eruptions, carbonatite intrusions, and on the many fragments of the deeper portions of the islands themselves that have been brought to the Earth’s surface in eruptions.

Prof. Hilary Downes graduated from Durham University and then spent 2 years in Canada, doing an MSc. She came back to the UK to do a PhD at Leeds University studying one of the extinct volcanoes of the French Massif Central. After a brief stay at Edinburgh University, studying mantle peridotite xenoliths, she was appointed at Birkbeck College, University of London where she has been for more than 30 years, teaching and doing research on terrestrial rocks. She developed an interest in the mantle of other planets, and spent some time working on meteorites at Johnson Space Centre in Houston Texas.”

Tuesday 13th September 2022

“The Lost Rivers of London and their Relationship to the Geology” by Diana Clements.

“Many authors have discussed where the Lost Rivers of London flowed but this talk will address why, with reference to the BGS 1920’s 6″ maps which detail the courses.  Much of the information to be shown comes from projects Diana has been involved with, or from recent large engineering projects under London.”

Diana is a member of the AGS and is well known by many as she used to be the tutor for Southgate WEA classes before Stephen Krause took over.  She has worked in the Palaeontology Dept. of the Natural History Museum for over 30 years, but her own research is centred on the Geology of London.  She is very involved with the London Geodiversity Partnership with the aim of identifying , conserving and interpreting London’s Geology.  Her interest in the Lost Rivers began when she was researching the Fleet for an exhibition in the Islington Museum back in 1995: ‘Beneath Our Feet, The Geology Of Islington.’

Tuesday 9th August 2022

Members Evening

No ‘Golden Egg’ competition this year but a variety of things going on thus:

Mike Howgate is going to run a fun and educational geological quiz via a screen presentation. Small teams will be bidding for the title of Geologist 1st Class! No prizes, no pressure either. In addition, members are invited to bring along their ‘Favourite Specimen’ from their collection with their name and where it was found or purchased and state why it is their favourite, or why it is significant to them. These can be discussed and admired during the evening. Members are also invited to bring along up to five items they would like identified. ie. rocks, fossils, minerals etc from their collections. There will also be a table of books, maps, geology handbooks, fossils, rocks and minerals for sale to raise funds for the AGS.

Tuesday 12th July 2022

“The Building Stones of London” by Mike Howgate M.Sc. and Chairman of the AGS.

“For a major world capital London is, surprisingly, deficient in an adequate local building stone. Just about every block and brick has had to be imported into the city. But where did they come from and how were they quarried, transported and utilised? From Kentish Ragstone used to build Roman Londinium, to exotic granites, gneisses and migmatites used to clad modern offices and shops, we will see how these stones have changed the face of the city.”

Mike Howgate  has a B.Sc. in Geology and an M.Sc. in Vertebrate Palaeontology both from London University; he is also a Fellow of the Linnean Society of London. He worked on oilfields in Libya, Indonesia and the North Sea before becoming a science teacher in Hackney and Haringey. He then moved into adult education working for the Geological Museum / Natural History Museum, Birkbeck College and the Workers’ Educational Association running courses in geology and leading numerous field trips. 

His major interests focus on dinosaurs and in particular the supposed link between dinosaurs and birds, of which theory he is a prominent sceptic. He is a long-standing member of the History of Geology Group of the Geological Society and has given them several talks on early reconstructions of prehistoric animals. 

As well as being the Chairman of the Amateur Geological Society he is also on the committee of the Hertfordshire Geological Society and has recently become the Recorder for Geology for the county of Hertfordshire. He is also a qualified City of London guide and runs a series of walks in London and day trips to local destinations. 

Many AGS members have been regular attendees at Mike’s WEA Geology courses and excursions. In fact many have joined the Society as a result of attending the WEA classes, and conversely many have joined the WEA courses after hearing about them through the Society, so they have been of mutual benefit.