Geological Society

Newsletter No.12

July 2020

Inside this issue: Editorial : Reg Nicholls

Editorial 1

The past few months of As we begin to think about coming season. Coprolite Mining in 1 Covid 19 measures in place the next season of Society The society’s committee is Cambridgeshire will have limited the meetings again, social meeting (virtually) to travelling to see new rock distancing will have a great How can YOU help 2 discuss what options are exposures that we all might effect on what we can safely open to us: we are have planned. Fortunately arrange. determined to provide some Fen Edge Trail News 3 there are now large Many of us are becoming form of programme whilst numbers of online geological adept at Virtual meetings “Staying Safe”. Online resources 4 resources being made and certainly this might be We will keep you informed available to “keep our hand one of our options for at in”.( See page 4) of our plans in good time September CGS talk 4 least the beginning of the

Coprolite Mining in Cambridgeshire

Dr Simon Kelly and Ken Rolfe area—notably the economic (ex of CGS) have just of brownish sands and geology. published a paper in pebbly conglomerate layers - Proceedings of the Geologists’ the brown coloration is from The hard, brown pebbles are Association detailing their the oxidation of the mostly phosphatised work from a new exposure of authogenic green minerals nodules—commonly called the Woburn Sands Formation such as glauconite. coprolites—although very (aka Lower Greensand in this Although there are only a few will actually be fossil area) near Upware. Those of few exposures in dung. Many of them are you who have previously actually internal clasts of attended field trips run by bivalves and ammonites. Simon for Geo-East and the The nodules gave rise to the GA, will be familiar with the “Great Cambridge Coprolite” trench that is examined in this rush of the 1860-70s about paper. This temporary trench which much has been is on private land—so not written by Bernard accessible to the public. Phosphate nodules in a O’Connor. The term piece of Woburn Sand The Cretaceous Woburn Sands “coprolite” was coined by Formation from Upware. Formation (c. 120 Mya) lies Cambridgeshire (eg Ely), the Buckland and was applied to unconformably upon the deposits of the Woburn fossil dung. It seems that he Jurassic Ampthill Clay and Sands Formation collected some actual fossil Upware Limestone Member. nevertheless have had a excreta from the Rheatic The rock itself is of a mixture great influence in the Bone Bed and Lyme Regis. geology of the Fen Edge Pa ge 2 Cambridgeshire Geological Society July 2020 Coprolite Mining in Cambridgeshire cont.

The only problem was that the nearby Commissioner's even powdered, the Pit, concentrated and then phosphate was very shipped by barge on the insoluble, so took time to be nearby Cam to be crushed bio-available as a fertilizer. and converted. Locally the The 1860s saw an expansion nodules were crushed in of the quarrying all around windmills such as at the Fen Edge in the south Angelsey Abbey and the Big east where the nodules Mill in Burwell. Possible occurred at shallow depth. remains of a processing Around this time a new plant can be found at the process for creating a Super site of the Burwell Chemical Phosphate that was soluble Manure factory beside was developed at the Lode (which can Rothamstead Research be accessed from the Cam at (Station) in Herts. This Upware). provided more impetus for It was said that he even had The industry was the mining of the coprolites References a pair of earrings made of widespread in the Fen edge, coprolites for his wife! In in our area. S.R.A. Kelly, K.R. Rolfe, The but came to an end with a the case of the nodules from The trench created by Kelly ‘coprolite’ bearing Woburn combination of a slump in the Greensand, many have and Rolfe was also Sands Formation, Lower agriculture and cheap guano signs of borings, so have instructive as it was bisected Greensand Group (Aptian) imports from S. America. been rolled around the sea by the back wall of old at Upware, Cambridge- As much of the mining was floor for some time. coprolite diggings—part of shire, UK, Proc. Geol. on valuable agricultural land, the trench being Assoc. (2020), Another Cambridge after extraction the land was undifferentiated backfill. Professor, Henslow (he of restored again for cropping. Trevor. D. Ford and Ber- During the mining, the the Botanic Garden fame) There are a few old pits and nard O’Connor : A Van- quarried material was taken demonstrated the disturbed areas remaining, ished Industry: Coprolite to a washing station (many phosphate- rich composition but much of the evidence of Mining, of these were mobile as the of the nodules and soon the industry that supported shallow working became MERCIAN GEOLOGIST their commercial worth as a up to 600 workers in the exhausted and the digging 2009 17 (2) fertilizer was appreciated. area, has gone. moved along) just north of How can YOU help? The Cambridgeshire varied talks as well as a host committee, to share the Geological Society depends of web based content. But load. If you have some spare an the efforts of a small we could do much more if time and feel you can help—

number of volunteers to we had the human resource then please get in touch.

populate the committee, to support us. We need You do not have to be an investigate potential LGS’s help , for example in expert geologist—just have and to produce output of researching potential new an enthusiastic interest. interest to the Society sites for our Local Geological membership. In normal Site applications, volunteers Your Society Depends circumstances, we for helping with the Fen upon You endeavour to provide a full Edge Trail initiative and of timetable of interesting and course expanding the Pa ge 3 Cambridgeshire Geological Society July 2020 Fen Edge Trail News

During this lockdown we were still able to keep working on the Fen Edge Trail. The number of volunteers who are covering the ground is steadily increasing and we would like to thank all of our contributors who are growing the number of walks we can publish.

Although our guided walks for Celebrate the Fens Day have not been able to take place, we took part in the celebration by Tweeting a photo from each of the 50 or so walks. For more information on the walks see www.fenedgetrail.org . The list of walks is steadily growing and these are easy to complete whilst socially distancing! On many of them, you might not see Preview of upcoming another soul! releases

To be published 2020 Peterborough to Farcet Sawtry to Woodwalton Earith to Needingworth Needingworth to St Ives Cambridge to Fen Ditton Reach to Burwell Burwell to Wicken Sutton to Haddenham Thorney.

Being developed Farcet to Yaxley Yaxley to Holme Holme to Sawtry Woodwalton to Upwood St Ives to Swavesey Swavesey to Willingham Willingham to Cottenham Cambridge: Castle Hill to the Sedgwick Wicken to Soham to Fordham Fordham to Also: Haddenham to Fen Ditton to Stow cum Quy Peakirk to Peterborough Wisbech Pa ge 4 Cambridgeshire Geological Society July 2020

Online and remote Geological sites

The Geologist Association have a wide range of content on its “Geology from your Sofa” pages. Go to https://geologistsassociation.org.uk/sofageology/ where you will find lots of things to do from your computer.

The British Geological Survey has a wealth of available resource on its website—not just “free to download” Geology maps. I found a database of scenic images in their archive http://geoscenic.bgs.ac.uk/asset-bank/action/viewHome and particularly liked the photos of old Survey workers from the 1800s—some of which, I reproduce below!

Sir Archibald Geikie B.N. Peach Sir Robert Murchison

CNHS— some CNHS activites will still be taking place this year . Please see the website for more details http://www.cnhs.org.uk/

Cambridge Natural Cambridgeshire Geological Society talk History Society programme Our first talk on 14th September will be a virtual one given by Dr Daniel Field. Dr Field is a Lecturer in evolutionary palaeobiology in the Department of Earth Sciences at Cambridge University, and a Fellow of Christ’s College. He also holds a UK Research and Innovation Future Leaders Fellowship. Originally from Canada, Daniel obtained his PhD from Yale University, and his research focuses on using the fossil record to understand how modern bird diversity and biology came to be. “An asteroid impact 66 million years ago may have wiped out the giant dinosaurs, but it also resulted in the rapid diversification of birds. From this point onwards, avian evolutionary history was changed forever, eventually giving rise to nearly 11,000 living species. Daniel Field explores the evidence for the early evolution of modern birds, and sheds light on how, when, and where modern bird diversity arose.” Details on how to access this talk will be circulated nearer the time.