Wales, although small, is renowned for its diverse geology. It is one of the birthplaces of geological science, with fieldwork commencing in the 1830s leading to the recognition of three early geological Periods—the Cambrian, Ordovician and Silurian. Elis-Gruffydd has in this delightfully illustrated, small book captured some of the excitement associated with Welsh geological discoveries. This is no ordinary field guide, but a book mingling geological history (the story told by the rocks) and historical geology (the stories of how geological discoveries are made). So, this is not a book to be carried in a backpack, but one to be dipped into before any fieldtrip, to add depth to one’s appreciation of an area.
Dyfed has selected nine areas throughout Wales, covering geology ranging from Precambrian to Pleistocene. He has placed these areas in stratigraphic order (it would entail a lot of travelling to follow the book in order) and told something of the geology and a great deal of the historical geology of each. The result is a delight to read that contains stories rich with intrigue.
Naturally, writ large is the story of Sedgwick, Murchison and their acrimonious falling out over the overlapping Cambrian and Silurian Periods. So is Lapworth’s solution to the problem—the erection of the Ordovician Period. But there are other stories too, such as much of Anglesey swinging between being Cambrian and Precambrian in age.
When, in 1849, Andrew Ramsey visited Anglesey with the Geological Survey of Great Britain’s director, Sir Henry De la Biche, he thought some of the rocks to be of Precambrian age. This was not the Survey’s view, so when Ramsay published his account of North Welsh geology in 1866, he toed the party line, writing that the Anglesey schists and gneisses were all of Cambrian age. Edward Greenly’s 1919 account, however, stated the metamorphosed South Stack, New Harbour and Gwna Groups to be Precambrian. This was reversed yet again when work on zircons in the South Stack Group plonked it firmly back in the Cambrian.
Such rollercoaster stories abound in this book, as do details such as Ramsay marrying Louisa Williams, whose father, the Reverend James Williams, was the great-grandfather of the famous Welsh artist, Sir Kyffin Williams. Dyfed also tells of Gerallt Gymro recording the submerged forests that line the Welsh coastline in 1188.
If you are heading to Wales, I recommend this book. If not, buy it anyway. It is a wonderful read.
Reviewed by Brent Wilson
THE ROCKS OF WALES: THEIR STORY, by Dyfed Elis-Gruffydd 2019. Published by Garreg Gwalch, Llanrwst, Wales. 160 pp. (pbk.) ISBN-978-1-84524-295-4
List Price: £8.00.
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