RGSC has moved to new premises. The rooms in the Old Fire Station, Penzance were damp and unsuitable so Cornwall Council have moved us to new offices on the site of King Edward Mine Museum. More news about this at the AGM.           A Face To A Name Some readers will recall an article I placed below (3 articles back) concerning a forensic examination of a boxed collection of minerals.  The owner was revealed as a Reverend Edward Budge who was an early member of the society whilst residing in Manaccan.  He moved to the parish of Bratton Clovelly in Devon and became rector in 1846.  A keen-eyed Australian noticed this article and made contact,  His name was Trevor Budge and was the great-great-grandson of Reverend Edward Budge. He had in his possession a photograph discovered in his father's effects, The photograph is shown below-a very studious character indeed.  It is very gratifying to put a face to the story! My thanks to the Society and to the internet which demonstrates how the world has shrunk and to the scope of the readership of the Society's affairs. John Cooke   Picture courtesy of Trevor Budge           Roy Starkey Lecture - 21 September 2022 The Royal Cornwall Geological Society teamed up with The Russell Society mineral enthusiasts and other participants to listen to an evening talk about the Rashleigh Collection at the Royal Cornwall Museum given by Roy Starkey of the Russell Society. The talk was recorded and can be viewed on the link here: Philip Rashleigh's Mineral Collection at the Royal Cornwall Museum and Why It is Important - Lecture Following the excellent talk by Roy there was some lively discussion (not recorded) and the points below were noted by Frances Wall, President of RGSC who chaired the evening. The idea for the talk came after the announcement by the Royal Cornwall Museum in July that it had not been awarded an in-year funding grant from Cornwall Council and this could lead to closure, hence the interest in learning about this famous collection and publicising its importance. Cornish Mineral Heritage (virtualmicroscope.org) 110 people joined the online talk and discussion, including from Australia (3), the USA (3), Sweden (1), Italy (1), and Scotland, Wales and England, demonstrating that the RCM collections and the Rashleigh Collection and archive in particular are truly special with an international reach and reputation. There is tremendous goodwill to help with the collection/museum. If RCM were to hold a workshop to engage with enthusiasts about interests and ideas for future development, it would be well-received and well-attended. The adult museum audience including ‘enthusiasts’ is an important group to engage with, as well as school groups, general tourists. There is an opportunity to link the enthusiast community better to expand activities such as schools outreach – using expertise gained over years of presenting minerals in schools. There was lively conversation about how much information should be presented with mineral specimens – people like labels! Ideas were discussed for a new storage and interactive facility  – equivalent to Kresen Kernow for ‘things’ such as archaeology and natural history or even a new larger exhibition of a World Heritage Site geocentre. There was concern for safeguarding the geological collections including the Rashleigh Collection because of the lack of a specialist curator, a role key in making the most of the collections – for research as well as public interaction – and in ensuring that the minerals are kept in good condition, and safe from potential interaction with unscrupulous parties. Achieving a formal designation for the collection is an important step in safeguarding and future fundraising. There was concern, especially given financial position of the Museum, about what would happen to the collection in the event the museum were to close and discussion of the good practice of having a contingency plan. Some better news since the talk is the release of UK Government ‘Town Deal’ funding for Truro on 26 September, which contains some funding for the development of the Royal Cornwall Museum exhibitions:  Video: First Town Deal funding | Business Cornwall The Truro Town deal includes a ‘New Life for City Buildings’ segment, one part of which is ‘Transforming the Royal Cornwall Museum into a contemporary heritage asset and a carbon neutral museum in the heart of the city. Improved access, new exhibition space and a digital learning lab will create a first-class heritage offer attracting 100,000 visitors each year.’ Frances Wall Mining walk and talk at Godolphin Cross -   17 August 2022                            Stephen Polglase led a guided walk for the RGSC on 17 August to view the site of one of Cornwall’s paramount former mines, “Great Work”, which lies in the saddle between the two granite outcrops of Godolphin Hill and Tregonning Hill in the World Heritage Mining Landscape west of Helston. Twenty eight participants joined to learn about the geology and mining history of this famous area. Now partly owned by the National Trust, the route of the walk was rich in old mine workings but most were hidden under vegetation adorned with handsome blackberries. Stephen explained he is not a geologist but his family have been mining in the area for generations. The group were fascinated to hear the first hand tales of former mining and of exploring some of the old shaft and adits. Besides mining geology, the group discussed the origin of an occurrence of rounded boulders and whether they might represent beach deposits despite even though they are so far removed from the coast. The evening sunshine and far reaching views over Cornwall contributed to a very pleasant excursion. After the site visit the group returned to the Old Chapel in Stephen’s home-village of Godolphin Cross, where they enjoyed an impressive and substantial array of very delicious cakes made by RGSC secretary Linda Beskeen, and hot pasties courtesy of membership secretary Beatrice Kerno. Stephen then continued by presenting a series of photos, old and new, together with commentary, explaining the fascinating history of ‘Great Work’, together with neighbouring mines, and its miners amongst which were Stephen’s antecedents including a Cap’n Polglase. We also received a description of the occurrence and nature of the various main mineral lodes and tin stockworks at Great Work, together with description and photos to illustrate both underground works personally undertaken by Stephen and his father in recent times, and even more recent trenching works by Stephen which had revealed not only the back of a lode in the base of the trench but also a backfilled shaft at the side. He brought with him some excellent specimens of minerals handed down through the family, including a magnificent quartz- crystal cluster, wolframite, galena, uranium minerals, and spectacular examples of cassiterite in disseminated and massive forms. All sparked (no pun) lively questions and debate (the writer takes the chance to reveal that east-Cornwall mine worked early for wolfram, on which he blanked, as “Drakewalls”!). The area of the visit and subject of the lecture, were equally dear to Stephen’s heart, and his depth of knowledge of mining around Godolphin Cross was matched by obvious enthusiasm. A final ‘corporate’ vote of thanks to Stephen for a most interesting evening and to Beatrice and Linda for their hard work and time in preparing and serving us with such a welcome range of refreshments." Nick Farrell Photos Frances Wall

A Mineral Detective Story regarding the Reverend Edward Budge and the Royal Geological Society of Cornwall

The purchase of a boxed mineral collection started a detective story with only two clues available; an obliterated address and a partial postmark. No catalogue was associated with the collection and it necessitated the identification of the specimens by a combination of friendly experts and X-Ray fluorescence.

It became obvious that the collection was of Cornwall and Devon origin displaying many classics for which the region is famous. A keen-eyed ex-Devonian resolved the issue of the postmark and the expert help of the forensic team of the local university led to the discovery of the address and origin of the paper on which it was written. The story revealed a geologically interested Reverend once residing in Manaccan and being continually active in the Royal Geological Society of Cornwall. The author, John Cooke, would welcome any further information on the geological interests of the Reverend Edward Budge and especially any comments on the boxed mineral collections assembled by the contemporary mineral dealers of the Southwest mining area.   Read more on the story in John Cooke’s article here.  Link

A Walk Across the Moho at Coverack - 15 May 2022   

The sun was shining on a glorious spring morning as 29 RGSC members and guests gathered at Coverack on Sunday 15 May to walk across the boundary between the Earth’s crust and mantle on a classic section of ophiolite, a piece of ancient ocean floor pushed up to the Earth’s surface during collision of two plates.

Just before low tide, the group picked their way across the boulders to the north side of the beach where they discussed magma chamber processes in the gabbro that forms the ocean crust, crystallised from mantle-derived magmas near a mid-ocean ridge 375 million years ago.

The group then moved south along the beach and ‘down’ across the ‘Mohorovičić discontinuity’ defined by geophysics studies of earthquakes as the boundary between the crust and mantle, reaching serpentinised peridotite of potential mantle material towards the south of the beach. In practice as the group found, the geophysicists’ line coincides with a change in density of the rocks but this may not actually be the petrological boundary at the base of the crust.  The density change seen in the geophysics signal could also be a build-up of cumulate ultramafic minerals that settle out from the gabbroic magmas.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               The photo below shows gabbro with evidence of magma chamber processes.   

After lunch (with sausage rolls from the local shop), the group visited an exposure on the shore just on the other side of the village to look at harzburgite and dunite mantle rocks that have certainly been the source of the magmas that moved up into the ocean crust.

And to answer a question from one of the participants: Coverack was first recognised as an ophiolite by a team of researchers from Memorial University Newfoundland and University of Southampton and published as a short abstract in 1975 in the Proceedings of the Ussher Society (Strong et al., 1975, Proc. Ussher Soc, 2, 252).

Thanks very much to Kate Moore (Camborne School of Mines, University of Exeter) for leading the group and her super explanations of some complex processes, and to Beatrice Kerno for organising registrations.

Easter Social at Penryn Campus - Looking into Rocks 20 April 2022

Twenty two RGSC members and guests took part in the Easter meeting on 20 April at Penryn University Campus. Calum Beeson, Senior Geology Technician at Camborne School of Mines (CSM) had facilitated use of the CSM Geology Laboratory for the evening and set up the petrological microscopes ready for use.

First up was a thin section of a Cornish granite (number I43) to follow on from the Carn Galver fieldtrip in February. Dr Sam Hughes, aka ‘@CornwallGeologist’ explained how to identify the main minerals under the microscope and, with the help of our able demonstrators, Peter Scott, Calum and Megan Shute, everyone learned more about the story of granite. Sam then put the granite minerals into wider context, linking the radiation damage halos in the biotite to geothermal energy and the alteration of feldspar to the kaolin mined at St Austell.

We then moved to the opposite end of the igneous rock compositional spectrum and had a look at an example of the kind of mantle rocks we will see on the 15 May field trip to Coverack. The actual Lizard rocks are rather heavily altered and not the best for beginner microscopists, and therefore Kate Moore suggested we ‘cheat a bit’ by looking at an altered peridotite from Kimberley, South Africa (I88). Kate couldn’t make it to the session, so Frances Wall led the group through looking at the mantle peridotite and especially bright and rather beautiful interference colours of its olivine, the Earth’s most abundant mineral. The group contrasted the irregular fractures in olivine with the 120 degrees cleavage in the amphibole and regular cleavage lines in pyroxene and mica.

After the microscope session, the group visited the Camborne School of Mines Museum for tea/coffee, cakes and conversation – with many thanks to Linda Beskeen for delicious baking! 

Photos and write up by Professor Frances Wall

Second Visit to Caerhays Castle - Saturday 30th April 2022

Here is a picture, courtesy of Colin Bristow, of the second RGSC group who enjoyed a visit to Caerhays Castle,    hosted by Courtenay Smale.  The group saw the Caerhays' Mineral Collection and then were taken on a visit to the castle gardens.

Visit to Caerhays Castle 26 March 2022