When working in the building restoration industry in London, I encountered very many different building stones – limestones, sandstones, granites, marbles and slates – and it seemed natural as a geologist to develop specialist stone matching skills, when presented with an architect’s specification that states: “All materials used for repairs shall match the existing”.
I don’t know if it is different now, but at the time there was no university or college courses to learn these practical skills and I just used a Natural Stone Directory, various Building Research Establishment Reports and various city building stone guides, particularly Dr. Eric Robinson’s London Illustrated Geological Walks, to develop an eye for the subject.
For the work I was doing, this was an essential practical skill but such building stone trails, including those used in cemeteries and churchyards, have since been considered as a valuable educational resource for teaching the basics of geology – for schools and various adult groups.
In South Yorkshire, I have made significant contributions to such guides in Rotherham and Sheffield and have led ‘urban geology’ walks with the Sheffield U3A Geology Group in Leeds and Sheffield and I have had a good look at the Sheffield General Cemetery, where there is a long established geological trail that is used often for guided walks.
Having had a quick look at the various stones used for the lodges and chapels in Burngreave Cemetery, I noted the use of at least two sandstones and, in the war memorial and Commonwealth War Graves, Portland limestone.
When continuing my walk back down to the main entrance, I could hardly miss the various stones used in the private memorials along the way, which could be used for educational purposes. Firstly, a large complex memorial with four columns topped by a dome and urn, which is made of black dolerite – a basic igneous rock of intermediate grain size that is composed mainly of the minerals pyroxene and plagioclase feldspar.
Without even searching them out, I came across three different granites, where quartz, alkali feldspar and the micas, biotite and muscovite, can be seen and if I had made the effort, I would have found several more – as well as white Carrara marble, which was widely used for angels and other figurative sculptures.
The older part of the cemetery that I saw is occupied by traditional Victorian headstones, made from slabs of the Brincliffe Edge Rock, the local variety of Greenmoor Rock, which developed a great reputation for its monumental quality.
The very fine grain of the Brincliffe Edge Rock made it very suitable for letter cutting, with a range of calligraphic styles and other shallow relief sculptural work, most of which are still in very good condition after more than a hundred years, although usually blackened.
Occasionally, the headstones are seen to have failed spectacularly, with the surface of the headstone having delaminated along the bedding planes, which has led to the complete loss of the inscriptions, but also reveals a fresh surface of the sandstone.
This part of the grounds was originally set out on part of the ancient oak woodlands of Burn Greave Wood, where a small group of sessile oaks with its carpet of bluebells has been retained and, although ivy is a big problem here, it provides a habitat for a wide variety of flora and fauna, which adds to its educational value.
Let me know if you are coming to East Anglia. Our churches have unusual geological dimensions!
ReplyDeletehttps://watermillsandmarshes.org.uk/upon-this-rock-the-geology-of-broadland-churches/
Thanks Tim.
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