Concretions in sandstone
Introduction
The photograph on this page of Concretions in sandstone by Jonathan Wilkins as part of the Geograph project.
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Concretions in sandstone
Image: © Jonathan Wilkins Taken: 30 Jun 2012
Variable cementing of the sandstone, Carboniferous in age, by carbonates has resulted in irregular weathering and the appearance of large, dark-coloured nodules on the eroded surfaces. The presence of bedding planes passing straight through some nodules is indicative of the structure being secondary in nature. The dark colour is largely due to the slow ablation of the surface compared to less heavily-cemented areas, and the surface is stable enough to be colonised by lichens (yellow Caloplaca is prominent).
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Image Location
Latitude
53.185249
Longitude
-4.399717