Geology

Although Dr Mary Gillham wasn’t a geologist, she paid close attention to the geology of landscapes and the chemistry of the ground beneath her feet to explain the communities of plants that she saw. Using the generous financial support of the Geologists’ Association Curry Fund, the purpose of this project has been to extract the geological (and relevant historical) information embedded within this archive.

One of the project volunteers, Archie, examined the 24 lever arch files (which constitute the majority of Mary's written notes) for any geologically-relevant information, categorising it by subject (such as Resource Geology covering anything related to mining, quarrying, etc.), and scanning the documents in which it was written. These have then been collated, with a directory, into one folder. Further to this, Archie filtered Mary's slides for those containing geological content and added tags as to the type of geology they showed.

Archie takes up the story. "This project has given me a detailed insight into the geology of Cardiff and South Wales, including outcrops of rock which are no longer exposed. It has also revealed information about the methods and history (including the decline) of local mining and quarrying. Mary was a member of several environmental and conservation organisations, which tended to come into conflict with mining and quarrying companies desiring greater expansion. Her records preserve the details of some of these past conflicts, and the arguments used by both sides. Interestingly, Mary did recognise the value of industrial heritage, so it has been interesting to see how she reconciled these viewpoints.

Further to this, Mary also described interesting aspects of historical geology. The Farewell Rock was a thick sandstone unit at the base of the Coal Measures and indicated to miners that neither iron ore nor coal would be extracted by mining any deeper; and ancient Romans mined Rhiwbina iron ore from Cwn Nofydd. She also documented significant events in Cardiff’s recent history (such as the regeneration of Cardiff Bay and the construction of the Bay Barrage, and converting the A48 into the M4) from a different, ecological perspective

Mary often related plants to the underground rock type, for example: “limestone plants” which included beech, ash, spindle, and dogwood among others. This gave me an insight into just how diagnostic plants can be in determining geology when there is nothing visible at the surface, and I will apply this information on fieldwork in the future."

Scanned slides of photographs of landscapes and geological important features will be made available to wider audiences in 2018 via GeoScenic (hosted by the British Geological Survey) by searching for Mary Gillham Archive. Scanned PDFs of relevant documents and digital copies of the slides, both with directories, are available upon request by emailing info@sewbrec.org.uk and requesting the Geology Collection, and will also be available as physical copies through the National Library Wales and Glamorgan Archives once the entirety of the Mary Gillham Archive is passed on to them.

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Thanks to the Geologists' Association for enabling us to achieve this aspect of the Mary Gillham Archive Project.

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