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.

Our meetings programme for Sept 2024 to June 2025 will be available shortly

Previous events

Visit: Sunday 14th July 2024 2.30pm to 4.30pm

Living Fossils of the Botanic Garden, Cambridge

Guided by Franziska Norman, Cambridgeshire Geological Society

Franziska will show us the ‘living fossil’ plants she described in her talk last April that are flourishing in the Cambridge University Botanic Garden. She will take us on a tour of the glasshouses and the garden to see the plants that have been growing somewhere in the world since the middle of the Jurassic Period.

Easy walking, all welcome. Free but you do need to pay entry to the Botanic Garden (£8, free for Friends of the Garden). Please book (as it is limited to 15 people) by emailing us on info at cambsgeology.org to reserve a place. Details of the meeting place will be given after booking.

Monthly talk: Monday 10th June 2024 7.30pm

My favourite fossils held at the Sedgwick Museum

Rob Theodore, Exhibitions and Display Coordinator, Sedgwick Museum, Cambridge

Learn about some of the amazing fossils that are held by the world-famous Sedgwick Museum of Earth Sciences in Cambridge. This will be a personal look at some of Rob’s favourites.

This talk will be in our usual venue at St Andrew’s Centre, Histon.

Walk: Friday 14th June 2024 morning (10.30am to 12.30)

Building Stones of Cambridge

Celebrating Cambridge Nature Festival

Guided by Penny Coggill, Chair, Cambridgeshire Geological Society

By popular demand, a repeat of the walk held on Friday 7th June 2024 which was overbooked.

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 walk 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.

 

Easy walking, about 1 mile total, all welcome, free (as it is part of the Cambridge Nature Festival) but you do need to book.Please email us on info at cambsgeology.org to reserve a place. Details of the meeting place will be given after booking.

Monthly talk: Monday 13th May 2024 7.30pm

Potential for carbon dioxide sequestration in volcanic rocks of the North Atlantic Igneous Province

by Dr Simon Passey, CASP

In the quest to achieve the objectives of the Paris Agreement, which aim to restrict anthropogenic warming to 1.5–2.0°C this century, carbon capture and storage (CCS) plays an indispensable role. The majority of CCS projects are focussed on the injection of carbon dioxide (CO2) into porous sedimentary rocks at greater than 1 km depth; these require impermeable overlying rocks to stop the CO2 escaping to the surface. An alternative approach, however, involves the injection of CO2 into reactive rocks (e.g. mafic or ultramafic lithologies) leading to carbonate mineralisation; this process permanently locks carbon away with minimal risk of it re-entering the atmosphere. The CarbFix project in Iceland has made significant strides in demonstrating the viability of this approach by injecting CO2 into basalt lava flows. The project is, however, on a relatively small scale and there are uncertainties regarding the feasibility of scaling up this technology for widespread commercial use, such as utilising the large volumes of volcanic rock formations of the North Atlantic Igneous Province (NAIP). These volcanic rock formations vary significantly in terms of facies, mineral composition, porosity and permeability, all factors that need to be addressed in adopting the CarbFix approach. The potential of carbon mineralisation within the NAIP will be explored and the challenges faced will be discussed.

Monthly talk: Monday 8th April 2024 7.30pm

Members evening – all welcome

A series of short talks and updates plus a chance to chat and find out more about geology and CGS. Light refreshments provided – please feel free to bring some contributions if you would like to. Non-members also very welcome. Includes:

Dr Terry Allsop – Old Svalbard

Chris Wagner. – Gault Clays in Cambridgeshire- An Engineer’s Perspective

     Lee Wells – Charnwood Forest

Monthly talk: Monday 11th March 2024 7.30pm

The interpretation of the periglacial landsystem through LiDAR

by Dr David Giles, Technical Director, Card Geotechnics Ltd

This presentation presents a review of the relict periglacial landsystem that gave rise to a significant ground legacy of geohazards and will demonstrate the advances in ground model assessment offered by airborne LiDAR (laser scanning) data sets for engineering geomorphology. High resolution digital elevation models derived from the LiDAR data can be utilised to interpret and visualise the on-ground geomorphology. Derivative models can be generated for hydrological studies providing a variety of new opportunities for ground model development. The available LiDAR data and generated models are described, and examples of their use presented from classic case study sites.

 

Monthly talk: Monday 12th Feb 2024 7.30pm

Ediacaran fossils in Namibia

by Dr Alex Liu, Lecturer in Palaeobiology, Dept of Earth Sciences, University of Cambridge

Dr Liu’s research investigates the interval of geological time encompassing the origin and radiation of animals, between ~700-520 million years ago. Much of his work has explored fossils of the Ediacaran Period (635-541 million years ago), particularly the enigmatic Ediacaran macrobiota – a group of soft-bodied organisms with unusual body plans that may include some of the earliest members of extant animal groups. This involves studies into taphonomy, ichnology, sedimentology and geochemistry, in a variety of field areas including Newfoundland (Canada), Brazil, and China and, recently, Namibia. In addition to gathering data that will enable full facies analyses of the siliclastic units containing fossils of soft-bodied organisms throughout the Nama Group, his group also discovered new fossil specimens (including novel taxa), logged new sections, and initiated collaborations with the Geological Survey of Namibia. They also found one of the most beautiful Rangea specimens you will ever see (now housed in the Museum of the Geological Survey of Namibia, Windhoek, specimen GSM F1726)!

Monthly talk: Monday 8th Jan 2024 7.30pm

(not the 15th Jan as previously stated)

The Northwest Highlands Controversy

– How one man’s ego held back science

by Dr Reg Nicholls, previous Chair of CGS

The North West Highlands of Scotland can be classed as one of the most complex and interesting geological areas in the world. Due to its complexity, it was amongst the last to be properly mapped and explained. To this day new observations/evidence allows us to revise its story. The elucidation of the geology was not helped by the massive ego of one of the giants of 19th century geology – Sir Roderick Impey Murchison! The story of the path to the geological truth has now been termed the “Northwest Highland Controversy”.

By the 1860’s Murchison was director of the Geological Survey and thus held great sway over the “accepted” opinion. Other academics who had studied the area were forming an alternative view of the geological story of the NW – but were “drowned-out” by the establishment. Murchison was on a mission to claim more and more territory for “his” Silurian system and was convinced that the mass of the rocks in Assynt were a conformable sequence of Silurian age – others (like Professor James Nicol of Aberdeen University) thought it was much more complicated. This had followed on from Murchison’s “brow-beating” of Adam Sedgwick into accepting the Silurian in Wales extended down to meet the Cambrian that Sedgwick had worked out.

By 1883, a new view was taken by Charles Lapworth (Prof University of Birmingham). He had already forced the Survey under Giekie (Murchison’s man) to have a volte face over the structure in the Southern Uplands and now he succeeded in establishing the true facts in the NW – much to Murchison’s displeasure. This talk will discuss the politics and personalities as well as the science that led to the fuller understanding of the rocks of the NW.

Monthly talk: Monday 11th Dec 2023 7.30pm

Introduction to the Geology of the Chalk Springs and Chalk Streams of Cambridgeshire

by Dr Steve Boreham

The Chalk Springs of Cambridgeshire provide a unique aquatic habitat and have a vital role in feeding the Chalk Streams that flow through the southern part of the county. These springs arise in a variety of styles and geological settings, and there is considerable debate about what constitutes a ‘chalk stream’. Spring types appear to be linked to the lithology and stratigraphy of the Cenomanian Chalk and their distribution may also be influenced by past glacial and periglacial activity. Understanding these variations is essential if the geodiversity of these landforms is to be preserved.

So far, CGS has obtained Local Geological Site designation for 4 Chalk Springs: Nine Wells (Cambridge), Burwell, Giant’s Grave (Cambridge) and Fowlmere. We are now researching others to propose them for future LGS status. These include those at Orwell, Fulbourn, Great Wilbraham and Bassingbourn. If you know of other Chalk Springs in the county, please let us know.

Monthly talk: Monday 13th Nov 2023 7.15pm

Paramoudra: the origins of flint at West Runton

by Russell Yeomans 

NB Please arrive by 7.15 om as our short AGM will precede the talk

Paramoudras are large, barrel or pear-shaped flints in the Chalk of Late Cretaceous age. Russell Yeomans has spent much of his life walking the beaches at West Runton on the Norfolk coast. The beach just so happens to be at the level of a huge flint raft in the Chalk that obviously extends for many miles. Thorough detailed analysis of these flints has led him to the realisation of what they have been formed from, and this he will explain to us in his talk.

Monthly talk: Monday 9th Oct 2023 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!

 

Monthly talk: Monday 11th Sep 2023 7.30pm

Shap Granite: geology, origin and celebrity

by Dr Nigel Woodcock, Department of Earth Sciences, University of Cambridge

The Shap intrusion (Cumbria) is one of a suite of related granites either side of the Iapetus Suture, the site of closure of the Iapetus Ocean in mid-Silurian time. The Shap rock was prized as a monumental stone since Victorian time for its attractive feldspar megacrysts. Early radiometric dating of biotite in the granite suggested a solidification age of around 400 million years, but later studies of feldspar and zircon have found ages as old as 415 Ma. Could the intrusions really have an intrusion history spanning at least 15 million years? The distinctive appearance of the Shap granite has resulted in boulders of it being identified as far away from east Cumbria as the Vale of York and Yorkshire coast. Victorian geologists wrestled with the question of whether this transport occurred by Noah’s flood or by the newly proposed glacial hypothesis.

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. £5 CGS members (non members £6, subject to space availability). 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.

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: 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.

Monthly talk: Monday 12th June 2023 7.30pm

Describing rock samples

by Dr Mike Tuke

 

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!

 

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

Prof. David Tappin, BGS

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

This talk will discuss a less well known feature of the fabled Northwest Passage: the four billion years of Earth history contained in the geology along the route. Alongside an overview of the spectacular geology, the talk will include a discussion of how geological research is conducted in the Arctic, how the region has contributed vital evidence in the ongoing debate about when plate tectonics started on Earth, and unexpected links with both Margaret Atwood and my College at Cambridge: Sidney Sussex. More info in this blog.

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

Dr Colin Summerhayes, Scott Polar Institute

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

Dr. Ekbal Hussain, British Geological Survey

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

BOOKING NEEDED

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

This walk makes use of the bus between Reach and Burwell to travel one way and walk back (or you can arrange to car share and leave a car at each end). The walk will start in Reach around 10 -10:30 am (exact time to be announced, depending on the bus timetable). We will have a brief look at the Totternhoe Stone quarry site in Reach, before walking a section of the Devil’s Dyke earthworks – passing the site of a Roman villa. We then cut into Burwell via Pauline’s Swamp nature reserve where (assuming there has been some rain) we can see some chalk springs. After crossing Stephen’s castle, we stop at Castle Spring LGS to see a rare exposure of the base of the Totternhoe Stone before travelling uphill and up the rock succession to Carter’s Pit – a disused quarry once dug to win the famous Chalk ‘clunch’ (the Totternhoe Stone again). We then make our way through the village – passing several historic sites and taking in the variety of local building stones in the walls and houses. The walk finishes at the edge of the Fens, once more, near the old industrial wharves on the Catchwater, running into Burwell Lode.
Length of walk 4.1 miles (approx 2.5 hours). For a slightly shorter option you can finish in the village centre rather than walk on to the lode. There should be the opportunity to grab a lunch in the various hostelries or the village coffee shop. Meeting place, exact timings and full details given on booking. For more information and to download the published Walk Guide see the Fen Edge Trail.

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

Volcanoes have long been recognized as important suppliers of volatile material like water, carbon dioxide, and sulfur dioxide to the atmosphere and environment. Volcanoes also shape the lives and livelihoods of over 100 million people on every continent. Recent advances in volcanology and instrumentation have demonstrated that volcanoes, like those that dominate the landscape of nations like Indonesia, emit significant quantities of volatile metals. In fact, individual volcanoes have been shown to emit as much selenium (Se), arsenic (As), and thallium (Tl) as the industrial pollution fluxes of whole countries. These vast quantities of aerosolized toxins represent a previously under-reported volcanic hazard that may present long-term health complications to nearby settlements. Yet, some of these metals may serve as micro-nutrients for bacteria, nourishing lush soil used or agriculture. Understanding how and why metals are emitted in volcanoes is a central goal of my doctoral research, and in this talk, I will share with you work addressing these concerns. I approach these questions by examining the chemistry and textures preserved in volcanic rocks, to understand how metals evolve in magmas located far below our feet. I focus my efforts on Java, Indonesia, one of the most volcanically active regions on Earth.

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.

U3A Geology groups

There are a few local geology groups run by U3A: Cambridge    Peterborough

Other Talks

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