Drummond Quarry
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Geology & landscape
Geological Feature: Rock Outcrop · Mining / Industrial: Quarry · Geological Period: Carboniferous · Rock Type: Limestone, Shale
Description
Drummond Quarry Carboniferous stratigraphy Drummond Quarry is the most easterly outcrop of the Bundoran Shale Formation and yields a shelly fauna that is diagnostic of the rocks age and typical of the formation. It offers the best exposure of Carboniferous rocks in the Aughnacloy area and has provided the evidence that allowed these rocks to be assigned to their correct stratigraphic position. These rocks are around 330 million years old. The best exposures of the Carboniferous rocks of this area are found at Drummond Quarry. The sequence here consists exclusively of some 8m of medium to dark grey calcareous mudstones and thin limestones; these are very fossil rich. Such lithologies are characteristic of the Bundoran Shale Formation. These rocks were previously assigned to the Ballyshannon Limestone Formation. Reappraisal of the exposures at Drummond Quarry allowed them to be reassigned to the Bundoran Shale Formation. Fossils are abundant in the quarry and include a range of solitary and colonial corals while the brachiopod fauna is particularly diverse. The assemblage of the solitary coral Siphonophyllia garwoodi and the colonial corals Michelinia megastoma and Siphonodendron martini is indicative of an Arundian age and is consistent with a correlation with the classic mid-Arundian 'Arnside Fauna' from south Cumbria. The presence of the Bundoran Shale Formation so far east at least 30km northeast of the nearest exposures in the Newtownbutler area and 50km east of the outcrop in the Derrygonnelly area is notable. Rocks here probably represent the margin of the mid-Arundian shale basin as there are no representatives of the Bundoran Shale in the Armagh basin, 20km to the east-southeast. https://www.daera-ni.gov.uk/publications/drummond-quarry-assi