Three more Local Geological Sites designated

Heydon Chalk Pit, Isleham Lime Kilns and Ramsey Heights Brick Kiln and Clay Pits were all designated as LGS in February 2023. This means that the landowners have agreed to maintain (and hopefully enhance) their geodiversity features and that the sites are now recorded...
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‘The Nature of Cambridge’ published

    This new book, written by volunteers from the Cambridge Natural History Society, has now been published (October 2022). Cambridgeshire Geological Society was pleased to be asked to contribute the chapter on the geology and landscape of the city, as a background to...
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Two new LGS

Two new LGS   In October 2022, two new sites were designated as Local Geological Sites. The first, Fowlmere Springs LGS, contains the most extensive collection of chalk springs in the county – the RSPB nature reserve of Fowlmere. The site is famous for its...
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Orwell Clunch Pit now a LGS

Orwell Clunch Pit now a LGS   Orwell Clunch Pit was designated a Local Geological Site in October 2021. The pit is also an SSSI for its chalk grassland flora. It is owned and managed by the Parish Council and is an attractive local ‘greenspace’ with...
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Two new LGS at Burwell

Two new Local Geological Sites designated at Burwell We are very pleased to announce that our latest proposal for designation as  Local Geological Sites (LGS) were recently (October 2020) approved by the County Wildlife and Geological Sites Panel. The two sites, 400m...
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The sea in the Fens

The Fens have been inundated by the sea on various occasions as shown by the marine silts and clays that can be found over large areas, even in the southern fenland of Cambridgeshire. The complex history of freshwater marshes changing to salt marshes and back again,...
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New Local Geological Site: The Great Fen

New Local Geological Site The Great Fen: Holme Fen and Whittlesea Mere LGS We are very pleased to announce that our latest proposal for designation as a Local Geological Site (LGS) was recently (Feb 2020) approved by the County Wildlife and Geological Sites Panel. The...
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Ice Age display, Sedgwick Museum

A superb mammoth tusk is now part of the Sedgwick Museum’s new Ice Age display. Sir John Franklin’s ill-fated expedition to the North-West Passage has often been in the news ever since he left England on the 19th May, 1845 never to return. Successive searches...
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Protecting the landscape heritage of the fens

The fenland has always been a land of mystery. This is particularly true when trying to unravel the complex history of dynamic changes in the landscape, which are directly linked to both sea level and climate. Thanks to an increase in research in recent years, much...
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Lime kilns at Isleham

Built around 1860, these listed buildings are the remains of a thriving clunch quarrying industry in this Fen Edge village. Three of the kilns are preserved, with the fire hearths visible inside. The clunch rubble was loaded in through the circular openings at the top...
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Promoting interest in the geology of Cambridgeshire, the UK and worldwide

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Building Stones of Cambridge Walk:

Friday 6th October 2023 10.30am

Led by Penny Coggill (CGS Chair)

For International Geodiversity Day

Cambridge is a beautiful city! Why? Because it has a great number of very fine buildings – university, ecclesiastical, public and commercial – built with some affluence, which meant the owners could use stone, and the more fashionable and pleasing to the eye that stone was the better. Join us for this guided tour around the city to see how these different stones were used, where they came from, how building and architectural fashions changed over time with improvements in transport and see what stones are used today to enhance the built environment. Our locally sourced stones tell us about the past environments of the area –  as seen in the fossils that many of them contain –  from Chalk ‘clunch’ to highly prized Jurassic limestones. Others, such as granites and ‘exotic’ pebbles tell the story of earth’s history elsewhere in the world. You will never walk through the city with the same eyes again.

All welcome. Approx 2 hours. Easy walking, about 1 mile. Free but must be booked. Contact us to book.


We have a programme of 10 Monthly talks running from September to June each year, held on the second Monday of every month. All talks (unless specified otherwise) are at 7.30 pm (doors open 7.00 pm). Everyone welcome, free to CGS members, £3 for non members. These are held at St Andrew’s Centre, Histon.


Monday 9th Oct 2023 (7.00 for) 7.30pm

Describing rock samples

by Dr Mike Tuke

Following on from our evening in June when Mike introduced us to various rock samples, this follow up session will give you more information and experience on rock identification. For ‘beginners’ this is a good introduction to the various types of rocks you may find (and some of the fossils they may contain), whilst for those more familiar with geology, it is a chance to gain more in-depth experience.

12 large rock samples will be on display and you will be asked to write a description of each sample. The descriptions can use non geological terms to cover, for instance, the colour, size, shape, texture and any visible features OR the descriptions can use appropriate geology terminology. During the last part of the evening Mike will give a geological description and interpretation of each sample. Bring paper and pencil!

Another Walk Guide published on the Fen Edge Trail

an iconic fen island  monks, marshes and a model village


In January 2023  the Walk Guide for the Thorney Fen Edge Trail walk was published. This walk is a good introduction to the geology of the northern part of the Cambridgeshire Fens, including silt from extensive tidal marshes and ancient river beds (roddons), the River Terrace Gravels of the Nene and the complex ’March’ Gravels. The latter created the island itself, raising it above the low fenland; these gravels also form the islands of Whittlesey, March and Chatteris.

All Walk Guides can be downloaded from the Fen Edge Trail website. 

The walk has been designed in partnership with Thorney Museum and the Thorney Society. We hope to organise a guided walk on the route later in the year.

4 New Walk Guides published on the Fen Edge Trail

December 2022,has seen the publication of 4 new Walk Guides including two with a difference: we have now expanded into the realms of podcasts and YouTube videos! Thanks to Paul S, Paul M (especially for the video) and Jeff for their work on the first three. Also thanks to Peter from the Word Garden who designed the fourth walk and produced the accompanying history podcast.

Sawtry to Wood Walton

Somersham to Earith

Haddenham to Wilburton

Earith: Old Bedford and 100 Foot with the Word Garden

This makes a total of 15 Guides published with at least another 7 due in 2023. An additional 21 are being put together leaving only 6 or so to be started. All Walk Guides can be downloaded from the website and there are also links to the podcast and videos. We hope to have guided walks on these and other Fen Edge Trail walks in 2023.

Previous Events


Field Trip Report – Burwell Local Geological Sites

The society organises occasional field trips to view important geological sites within the county and hopefully further afield in post pandemic times. These trips are primarily for our members.

In early summer 2021 we had a popular visit to the Burwell Local Geological Sites and are scheduling some others to East Pit, Cherry Hinton, a walk along the Fen Edge from Swaffham Bulbeck to Reach, a visit to Nine Wells chalk spring and a tour of the building stones of Cambridge city center. These are primarily for the benefit of members: any member wishing to participate should contact us.

A write up for this trip may be found here.



Our Spring 2023 newsletter is now available to members.

Our previous newsletters are available to everyone (download below). They have plenty of ideas for some virtual geology!

CGS Newsletter Winter 2022-23

CGS Newsletter Autumn 2022

CGS Newsletter Dec 2021

CGS Newsletter August 21

CGS Newsletter April 2021

CGS Newsletter December 2020

CGS Newsletter July 2020

CGS Newsletter April 2020

Email updates

Sign up for our email updates to hear about future talks, events and news of our projects.

Contact us



Cambridgeshire Landscapes

Cambridgeshire has a fascinating landscape and an interesting geology. See our Landscapes page for more details and download the excellent leaflet ‘The Mapping of Landscapes, Geology and Soils of Bedfordshire and Cambridgeshire’ by Timothy Farewell, Peter Friend, Martin Whiteley and Joanna Zawadzk.


Our talks and other events

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Local sites

Chalk cliff East Pit



Hippopotamous, Sedgwick useum


Local landscapes

The Fens




The Fen Edge Trail

Landscape Heritage

Mare Fen, Swavesey



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