Golden Hill Quarry, Devauden
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Geology & landscape
Mining / Industrial: Quarry · Geological Period: Carboniferous
Landscape processes: Volcanic / Igneous
Description
Description The volcanic neck exposed in Golden Hill Quarry is the most southerly major occurrence of mantle derived xenoliths in Britain. The neck, of probable Lower Carboniferous age, is composed of vent agglomerate and massive monchiquitic basanite. Both rock types contain abundant mantle xenoliths and megacrysts. The xenolithic rocks include lherzolite, harzburgite and wehrlite. The megacrysts include clinopyroxene, orthopyroxene, spinel and phlogopite. These materials provide a unique insight into the mantle composition under southern Britain during the Carboniferous Period and for this reason the site is of national importance.