Monthly talks and occasional Field trips
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. Talks are held at St Andrew’s Centre, Histon: Hall 1, St Andrews Centre, School Hill, Histon, Cambridge CB24 9JE. The Citi 8 bus stops outside the Centre and the Guided Bus is 15 minutes walk away. There is a free car park approximately 200m along the road just past a small supermarket.
We organise a few Field trips each year. These include visits to local sites with geological interest and walks on the Fen Edge Trail to explore the landscape, geology and associated history. Most are open to everyone and often free (or with a small charge to non-members). All require booking by contacting us. Children are welcome at talks, on walks and on some field trips, usually free of charge but anyone under 18 needs to be accompanied by an adult. Free Walk Guides to our series of Fen Edge Trail walks can be downloaded here.
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!
Fen Edge Trail Walk: Saturday 17th June 2023 10.30am
For Celebrate the Fens Day
‘through the fen edge town that became one of the world’s most famous cities’
Led by Martin Evans, CGS Fen Edge Trail Team
Approx. 2.5 hours to 1 pm. For Celebrate the Fens Day, this walk starts on the distinctive landscape feature of Castle Hill (a Chalk hill) and finishes at the Sedgwick Museum of Earth Sciences. It gives a landscape heritage and geological perspective to the city: the river’s gravel terraces, the chalk stream-fed river and the ‘fen’ meadows of alluvium and peat. The walk will also draw attention to buildings and places of historical and social interest. Guiding you through what is now a mostly hidden landscape, the walk takes you back in time, giving a glimpse into the city’s past and the natural history of the area, from ‘Ice Ages’ to sub-tropical swamps and fenland rivers. You will discover how its natural character still filters through, seen in the riverside meadows, the numerous water channels, the subtle changes in the height of the land and even in the building stones used in many of its famous buildings.
All welcome. Free as part of Celebrate the Fens Day but needs booking in advance. Easy walking, about 3 miles. For more details see the website www.fenedgetrail.org where you can also download the full Walk Guide. Contact us to book.
Visit to Cambridge Botanic Garden to see ‘Living Fossils’: Tuesday 27th June 2023 10.30am – 12 noon
Led by Franziska Norman, CGS
Following Franziska’s fascinating talk on ‘Living Fossils’ to CGS in March, she has arranged a visit to the Botanic Garden where she will give a tour of the Garden to take in these ancient plants and see how they are growing and surviving in the UK.
The cost is just the usual entrance fee to the Garden of £7.20 or £8 including Gift Aid (free for Friends of the Garden). However, that will allow you to explore the garden after the tour is over and take refreshment in the café.
All welcome. Needs booking (more details given after booking). Easy walking. Contact us to book.
Fen Edge Trail Walk: Sunday 2nd July 2023 10am
Thorney – ‘an iconic fen island – monks, marshes and a model village’
Led by Dot Halfhide (Thorney Museum) & Penny Coggill (CGS Chair & Fen Edge Trail Team)
In partnership with Thorney Museum and the Thorney Society. Well-known for its ancient Abbey, Thorney is also a good example of fenland’s interesting geological history. This will be a guided Landscape Heritage walk on the Fen Edge Trail on the ‘island’ of Thorney. The walk will cover cultural history, fenland landscape and geology. Thorney, the ‘Isle of Thorns’, was a fen island surrounded by marshes until the drainage projects of the 17th century. It has been known since the 7th century for its major Benedictine Abbey; the large Abbey church remains impressive, even though much of it was lost in the 16th century. The Victorian village is of the characteristic local brick and is famous for being a ‘model village’, built in the 19th century under the Duke of Bedford’s ownership.
All welcome. £3 per person (payable in advance). Children free. Needs booking. About 2.5 hours to 12.30pm. Easy walking about 2 miles, slow walk, some on pavement, most on grassy tracks. For more details see the website www.fenedgetrail.org where you can also download the full Walk Guide. Contact us to book.
Field trip: Sunday 16th July 2023 10am
Great Fen Local Geological Site
Led by Dr Steve Boreham, Chris Donnelly (CGS Geosites Team) & Henry Stanier (Wildlife Trust BCN)
Over recent years, the CGS Geosites team, with the help of Dr Steve Boreham, has been working with The Wildlife Trust BCN to highlight the geological importance of this key fenland site, also obtaining its designation as a Local Geological Site. This guided visit will explore the area to provide an understanding of the geology of the local and wider Fens and how it relates to both ecology and local history. We will see Holme Fen, which contains the remains of raised bogs and some of the deepest peat still surviving in fenland, and also the site of Whittlesea Mere, which has extensive deposits of shell (lake) marl. Underlain by Jurassic clay and ‘Ice Age’ gravels, the area also contains the ‘Fen clay’ from the Bronze Age marine incursion, seen within complex layers of buried peat or in small roddons at the surface, and the site of the ancient Trundle Mere, near to where the old River Nene enters the fenland. We will examine a core taken through the layers of peat that reveal the local history from the Neolithic and Bronze Age to the present. Visiting five sites, this will give a ‘behind the scenes’ insight into the Great Fen habitat restoration work and include a walk in Woodwalton Fen National Nature Reserve to enjoy the wildlife and see the historic Rothschild Bungalow. The area is rich in history and we will see the Holme Posts that show the dramatic effect of fenland drainage (particularly that of the famous mere), limestone blocks once destined for the walls of historic buildings as well as the remains of the old brick kiln at Ramsey Heights.
Easy walking during a few short walks. We can use the ‘facilities’ at Ramsey Heights Countryside Classroom, where we meet at 10 and return for a late lunch (coffee/tea/soft drinks provided but you will need to bring a picnic lunch). You will need to drive (in own vehicles) from Ramsey Heights Nature Reserve to the other sites – lift sharing may be possible.(Unfortunately, there is very limited public transport to within walking distance of Ramsey Heights NR and none to other sites visited). Info: www.wildlifebcn.org/nature-reserves/ramsey-heights. Full itinerary, maps and times provided after provisional booking. Shared minibus transport from Cambridge (cost TBA) may be possible for those who would like it. £5 CGS members (non members £6, subject to space availability).
Building Stones of Cambridge Walk:
Monday 29th May 2023 10am
For GeoWeek and Cambridge Nature Festival
Led by Penny Coggill (CGS Chair)
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. 2.5 hours to 12.30pm. Easy walking. £3 per person (free for CGS members). Needs booking. Contact us to book.
Fen Edge Trail Walk: Sunday 21st May 2023 2.30pm
(postponed from 14th May)
The Old & New Bedford Rivers, Earith
‘along the great drains created in the 17th century by the Company of Adventurers’
Led by Peter Daldorph (The Word Garden) and Chris Donnelly (CGS Geosites & Fen Edge team)
This walk, at the southern end of the Ouse Washes near Earith, visits the two great ‘drains’ that created the Washes which now play a vital role in the flood management of the Fens whilst also being an internationally important wildlife conservation area. You will learn about the incredible construction of the the 100 Foot River (also called the New Bedford) by the Company of Adventurers in the 17th century during the ‘Common Wealth’ and the rule of Oliver Cromwell. This is also a good area to visit to understand the changes in the course of the River Great Ouse as it enters the fenland, and its links with the Old West River and the West Water.
All welcome, needs booking. £3 per person (to be paid in advance), children (under 18) free. Easy walking, about 2 miles, 1.5 hours to 4pm, but a longer walk is possible for those who wish. For more details see the website www.fenedgetrail.org where you can also download the full Walk Guide and accompanying podcast. Contact us to book.
Previous talk: Monday 15th May 2023 7.30pm
(NB The 3rd Monday in May not the 2nd, to avoid the bank holiday)
The Hunga Tonga-Hunga Ha’apai eruption and tsunami
– learning from recent events
The Hunga Tonga-Hunga Ha’apai tsunami on the 15 January 2022 was the first from a violent eruption for over 130 years, the last being Krakatau volcano eruption in Indonesia in 1883. The event was also the first dual eruption tsunami since Krakatau and the first recorded by modern technology. The resulting shockwave was the largest and most significant ever recorded, with the associated plume the highest on record. This talk covers the event and its ramifications in providing information critical to developing mitigation strategies from these events.
Previous talk: Monday 17th April 2023 7.30pm
(NB The 3rd Monday in April not the 2nd, to avoid Easter)
Living Fossils in Cambridge University Botanic Garden
Franziska Norman, CGS Committee and ex Chair
This talk will introduce you to plants that have survived practically unchanged for many millions of years and so have become a living window into the time of the dinosaurs. Fortunately, although none of them are native to the UK, you don’t have to travel far to see them, as many of these can be found in Cambridge University Botanic Garden!
Previous talk: Monday 13th March 2023 7.30pm
The geology of the Northwest Passage
Dr. Owen Weller, Department of Earth Sciences, University of Cambridge
Previous talk: Monday 13th February 2023 7.30pm
Fossil brachiopods shells as outstanding archives of climate in the deep past
Dr. Claudio Garbelli, Department of Earth Sciences, University of Cambridge
Brachiopods are present in the marine benthic communities all over the Phanerozoic and they were the dominant bivalved organisms in the Palaeozoic. Their calcite shells have a high preservation potential, allowing the palaeobiologists to reconstruct their life histories from individual to community level. Because their physiology constraints, these organisms change in response to environmental parameters, and they thus represent a powerful archive of past oceans conditions and climatic variations. Also, their episodic growth patterns provide a sequential record of growth increments which can then be analyzed through morpho-structural and geochemical proxies for tracing environmental variables even at seasonal scale. Fossil brachiopods shells can thus be considered excellent archive for the study of ancient ocean condition.
Previous talk: Monday 9th January 2023 7.30pm
An evening of short talks by members
Dr Mike Tuke: ‘The cooling of teapots and igneous intrusions’ By thinking about the factors which control the speed of cooling of teapots we can see how these same factors affect the speed cooling of igneous intrusions and thus of the degree of metamorphism. This will involve the presence of Teapots!
Lee Wells: ‘Basalt Trap Feature rocks’ A collection of igneous ‘lumps’ from ‘trap stone’ sites.
Dr Martin Evans: ‘Phonolite – the singing stone‘ A quick look at the distribution, geological origins, and mineralogy of this uncommon extrusive rock and its use for roofing (and xylophones!) in central France.
Penny Coggill: ‘Lost industrial heritage of Cambridgeshire’ On a recent ‘Investigating Old Maps’ course at U3A a short end-of-course presentation was required. There are a huge number of old quarries (pits) around the villages of Cambridgeshire – most of which are “invisible” to all but inquisitive minds. I sought to use one set of early OS maps to identify as many of the old pits, quarries, kilns, wells as I could all of which were dependent on the underlying geology. This, I hoped, would help to identify potential Local Geosites within the county.
Dr Reg Nicholls: ‘The Borrowdale Volcanics group – arguably the most attractive Rocks in England!’
Previous talk: Monday 12th December 2022 7.30pm
Paleoclimateology from Snowball Earth to Anthropocene
This explains how greenhouse gases and temperatures varied through time, giving us alternating periods of warm ‘greenhouse’ climate and cold ‘icehouse’ climate over the past 800 million years. It explains how it is that Antarctica was once covered by subtropical forests, and why ice sheets did not cover it until 34 million years ago. It also explains the origins of the global Ice Age of the past 2.6 million years, explores the roles of the Sun and of the Earth’s orbit in controlling past climate change, and provides a past natural analog for today’s unnatural global warming. The past is the key to understanding the future.
Previous talk: Monday 14th November 2022 7.30pm
Natural Hazards turning into disasters
Globally, two thirds of deaths arising from natural hazards in recent decades were caused by geological hazards. But how and why do natural hazards turn into disasters? In this talk I will explore this question through the lens of one particularly troublesome hazard: earthquakes. The death toll for a given earthquake magnitude (and mechanism) will depend on geographic location, the social vulnerability of communities and the quality of the building stock. This talk will compare and contrast global trends in earthquake fatalities and aim to extract common themes that exacerbate the impact of natural hazards, and consider where and why these turn into disasters.
Previous walk: Saturday 29th October 2022 c.10am
Additional walk due to popular demand!
Guided walk from Reach to Burwell
Fen Edge Trail guided walk, visiting two Local Geological Sites, Carter’s Pit and Castle Spring at Burwell, led by Dr Reg Nicholls, Chairman of CGS Free to CGS members and to non-members in celebration of the Festival of Geology.
Previous talk: Monday 10th October 2022 7.30pm
Darwin and the geology of Galapagos
Prof David Norman, Dept of Earth Sciences, University of Cambridge
Charles Darwin is, of course, justly famous for his detailed compilation and analysis of the evidence that formed the basis for a non-theological explanation of the diversification of organic life on Earth through the publication of “On the Origin of Species” in 1859. His subsequent books reinforced these views, and history shows that he was able to establish new branches of scientific investigation, and that his theoretical model was largely correct – even though he couldn’t induce the underlying mechanism that made it all happen. As a consequence, he stands alongside Newton as one of our intellectual pillars. But what if he had not published for fear of offending society and his deeply religious wife Emma: would we even remember him? I think we most probably would remember Darwin because the early part of his career saw him establish himself as one of the most able observational and interpretative geologists in the world (Geikie was shocked to realise this in 1907!) – Darwin just got distracted from his “first love” by all those organisms.
Previous talk: Monday 12th September 2022 7.30pm
Metals in Magmas: Tracking Metal Chemistry and Magmatic Processes in Indonesian Volcanoes
Dr Nick Barber, Dept of Earth Sciences, University of Cambridge
Previous Field trip: Saturday 18th June 2022 10.30 am
for ‘Celebrate the Fens‘
Fen Edge Trail landscape heritage guided walk on the Isle of Ely
Free, everyone welcome, but numbers limited so you need to book by contacting us.
The Fen Edge Trail is a series of (about 48) walks in Cambridgeshire that take you along the fen edge, guided by where the low fenland meets the higher land above about 5 metres above sea level. Downloadable Walk Guides give details of the walking route and the places of historic, cultural and wildlife interest that you see, as well as describing the local landscape and geology. This guided walk is on part of the Sutton to Haddenham walk, but is adapted to be a circular walk from Haddenham. Total 7.5 km (4.7 miles) and c.2 to 2.5 hours. Relatively easy walking, with one main slope up North Hill (from 20m in c.0.5 km) and a more gentle slope (up 20m over c.2 km). Shorter option (c.5 km/3 miles) possible (c.1.5 hours).
Starting in Haddenham, we will walk along the street out of town and then turn up through orchards to reach North Hill, at 40m above sea level, the highest point on the Isle of Ely and in the southern Fens. The hill is part of a ridge formed of c.155 million year old Kimmeridge Clay and Woburn Sands sandstone that runs along the southern edge of the Isle of Ely. Bring refreshments to have whilst enjoying the great views from the ridge across to Sutton to the north and towards southern Cambridgeshire to the south. The route and meeting details will be sent after booking.
Previous Talk: Monday 13th June 2022 2 pm
Brimham Rocks – Yorkshire’s answer to Cappadocia
Dr Reg Nichols, CGS Chair
Yorkshire folk are often quoted as saying that in Yorkshire everything is bigger and better – perhaps Brimham Rocks near Harrogate fall into that category! This National Trust park has amazing natural stone pillars that rival anything seen in Cappadocia Gorem National Park. They are of Carboniferous age, Millstone stacks that tower on top of a plateau rising up from the Nidd valley. Their 3 dimensional aspects display the fluvio-deltaic sedimentary structures beautifully. Deposition was in a braided river system fed from the Calidonides to the North East infilling the Variscan Craven Basin systems. Far from being constructed by Druids or the result of the biblical deluge, these rock formations are thought to be the product of glacial assisted sand and ice blasting.
Previous Field trip: Wednesday 8th June 2022 2 pm
for Cambridge Nature Festival
Fen Edge Trail landscape heritage walk in Cambridge
from Castle Hill to the Sedgwick Museum
Free, everyone welcome, but numbers limited so you need to book by contacting us.
The Fen Edge Trail is a series of (about 48) walks in Cambridgeshire that take you along the fen edge, guided by where the low fenland meets the higher land above about 5 metres above sea level. Downloadable Walk Guides give details of the walking route and the places of historic, cultural and wildlife interest that you see, as well as describing the local landscape and geology. This guided walk (3 miles easy walking, taking about 1.5 – 2 hours) celebrates the publication of the Walk Guide (available by June) for this part of the Trail that passes through the ‘fen edge’ city of Cambridge. It links the walk into Cambridge along the north side of the River Cam from Milton (which finishes at Castle Hill) to the walk that continues on from Cambridge to Fen Ditton (starting at the Sedgwick Museum), along the south side of the river.
Starting high up on Castle Hill, you walk down through the heart of old Cambridge and traditional riverside grazing ‘fenland’, past historic buildings to finish at the world-famous Sedgwick Museum of Earth Sciences. The hill is part of a ridge formed of c.100 million year old Marly Chalk topped by gravel from an old terrace of the Cam, whilst the rest of the walk takes you across younger river terraces, dating from the last few hundreds of thousands of years and over much younger (probably only hundreds of years old) river alluvium alongside the river. Your guide, Martin Evans, is a committee member of CGS, an alumnus of Cambridge University and a long-term resident of Cambridge. He will be pointing out man-made features of historical interest on the way (which Cambridge has in abundance!) as well as commenting on the geology beneath at relevant points. As well as learning about the landscape of the Cam Valley, past and present, you will discover how it related to development of the ancient town and finally the city. You will also see a variety of local and exotic building stones. The walk goes past several colleges and takes in the famous ‘backs’, including the iconic view across the river to King’s College Chapel, as well as the nationally-renowned Fitzwilliam Museum. Famous pubs and tea shops are not forgotten, either!
Previous talk: Monday 9th May 2022 7.30pm
Celebrating GeoWeek 2022 7-15 May
Geoconservation past, present and future
Dr Colin Prosser, Natural England
Although most people think of wildlife when they think of nature conservation, geology is part of nature and geoconservation is part of nature conservation. Britain has been a world leader in geoconservation since 1949 when the government passed the first national nature conservation legislation which explicitly made provision for geoconservation.
This talk explores the origins of geoconservation in Britain, how it became recognised and included in legislation, how sites worthy of conservation were identified, and how it has evolved to where we are today. It touches on Local Geological Sites, Sites of Special Scientific Interest, National Nature Reserves, UNESCO Global Geoparks and World Heritage Sites, the rapidly growing global interest in geoconservation and the challenges and opportunities facing geoconservation in the years ahead. In doing so, this examination of geoconservation past, present and future will explain the links between boulders, lunacy, ‘robot planes’, a Cambridge geologist and the 6th of October.
Dr Colin Prosser is the Principal Geologist at Natural England, the government agency responsible for nature conservation in England. He has over 30 years of experience in geoconservation, applying legislation, shaping policy and developing practical approaches to conservation on the ground. He is a past President of the Geologists’ Association, a member of the UK Committee on UNESCO Global Geoparks and of the Black Country UNESCO Global Geopark management Team and has served on the Geological Society of London’s Geoconservation Committee. He is an editor of the Proceedings of the Geologists’ Association, specialising in papers on geodiversity and geoconservation, and has published over 100 papers, books and articles on geoconservation.
Previous Field trip: Sunday 8th May 2022 10.30 am
Celebrating GeoWeek 2022 7-15 May
Building Stones walk in Cambridge
a guided walk starting at the Sedgwick Museum
As part of GeoWeek, this walk is open to everyone and free of charge, but needs to be booked as there are limited spaces. Book by contacting us.
A walking tour, starting at the Sedgwick Museum of Earth Sciences on Downing St, around the city centre to spot the variety of building stone used in its construction. Many of the ancient University buildings used a variety of fairly local building stones – e.g. clunch (Cretaceous Chalk) from East Pit at Cherry Hinton and Barnack and Weldon Jurassic limestones. Other, more exotic stones, can also be found at various sites in the city, including the shopping centre. Local cobbles, found in fields on the surrounding hills (but many brought from far away by ice sheets), have also been used for the walls of some buildings and on trackways. More information on Cambridge’s building stones can be found here.
Previous talk: Monday 11th April 2022 7.30pm
Plesiosaurs, Pliosaurs & more – excavating the Jurassic’s marine reptiles
By Richard Forrest, Chair of Peterborough Geological and Palaeontological Group
The fenland of eastern England is underlain in many places by Jurassic clays which have been heavily exploited for brick-making and other commercial purposes over the past two centuries. Many thousands of fossils of marine reptiles have been uncovered during quarrying operations and form the largest such collection anywhere in the world. In many cases, bones can be retrieved undistorted and free of matrix; much of our knowledge of the anatomy of plesiosaur and other marine reptiles is built on these finds. Bricks are still manufactured on a large scale and, although highly mechanised extraction destroys many fossils, significant new finds are still being made.
This talk centres on the excavation of two such specimens, a pliosaur from the Kimmeridge Clay of north Lincolnshire and a juvenile specimen of Cryptoclidus, a long-necked plesiosaur, from the Oxford Clay near Peterborough. Their importance lies not only in the fossils themselves but in the scientific information we can retrieve from careful and systematic recording of their excavation.
Other organisations’ events
Friends of the Sedgwick Museum
The Friends organise a series of lectures in Cambridge (doors open, 6.15 pm for 7.00 pm in the Department of Earth Sciences) during autumn and winter and field trips during the spring and summer. They also organise overseas field trip in the UK and overseass. More information.
Cambridge Natural History Society
CNHS organise a series of talks (winter) and excursions (all year). Talks are usually held at the Attenborough Building next to the Zoology Museum. Visitors welcome (small charge) More information.
Courses at the Institute of Continuing Education of University of Cambridge
The ICE holds many interesting courses, at Madingley Hall near Cambridge, including some on geology, local landscape, evolution and archaeology e.g. Extinctions: crises in the history of life with Peter Sheldon
Free online courses
Future Learn has a number of short, online courses on geological and related subjects. These courses are free and very easy to follow. Ideal for introductions to many subjects. Courses include Extreme Geological Events, developed by Cardiff University, The Earth in my pocket: an introduction to geology and Extinctions Past and Present.
The Open University has free, online courses on Geology, for example: Earthquakes, Geological Processes in the British Isles, Introduction to geology, An introduction to minerals and rocks under the microscope, Life in the Palaeozoic, Mountain building in Scotland, Plate Tectonics, Volcanic hazards.
For details of many other talks and societies in the Cambridge area see the CONDUIT publication issued by the Cambridge Antiquarian Society. It gives contact details for the many organisations working to promote interest in history, particularly that of Cambridgeshire. The latest issue of CONDUIT can be downloaded from their website.
© Cambridgeshire Geological Society