Balmedie Quarry

Site of Special Scientific Interest · 57.2535, -2.0939

Also within

Aberdeenshire County

Condition (NatureScot)

Favourable (1)
UnitFeatureConditionArea (ha)Assessed
F1 Caledonian Igneous Favourable 2013-03-12

Geology & landscape

Mining / Industrial: Quarry · Rock Type: Gabbro

Landscape processes: Volcanic / Igneous

Description

BALMEDIE QUARRY Balmedie Quarry is located by the village of Belhelvie, 10 km to the north of Aberdeen. The quarry provides superb examples of the deformation of layered gabbros of the North-east Grampian Highlands’ unique ‘Younger Basic’ group of intrusions formed during the Caledonian mountain-building event. These gabbros, part of the Belhelvie intrusion, were deformed during tectonic events associated with the later part of the Caledonian orogeny. Small-scale layering and lamination of the gabbros are still often recognisable but have been thoroughly modified locally by intense shearing and crushing, to give rise to gabbroic schists and mylonites. Changes from the original high-temperature mineral assemblage (olivine, pyroxene, calcic plagioclase), to lower-temperature assemblages (including amphibolite, biotite and sodic plagioclase), are also evident. The gabbroic rocks have also been cut by granitic sheets (sometimes pegmatite composed of very large crystals), and some of these have also been tectonically deformed. In addition, a small strip of metamorphosed sediments, altered by the heat of the neighbouring gabbro intrusion to form hornfels, occurs in the eastern part of the quarry.