Craighead Hill Quarry

Site of Special Scientific Interest · 55.4957, -3.7124

Also within

Lanarkshire County

Condition (NatureScot)

Favourable (1)
UnitFeatureConditionArea (ha)Assessed
F1 Carboniferous - Permian Igneous Favourable 2009-02-20

Geology & landscape

Mining / Industrial: Quarry · Geological Period: Carboniferous, Permian · Rock Type: Basalt

Landscape processes: Volcanic / Igneous

Description

CRAIGHEAD HILL QUARRY Craighead Hill Quarry, lying approximately 1km north-west of Abington, is important as it includes an example of an intrusion formed by an unusual and visually striking rock type known as theralitic essexite. During the Carboniferous and Permian Periods, volcanic activity was not confined to the Midland Valley rift-valley and numerous examples of both volcanic and intrusive activity can be found elsewhere in southern Scotland. Craighead Hill Quarry in the Southern Uplands is important because of an intrusion of theralitic essexite exposed during quarrying activity. This is a rock whose chemical composition is that of a basalt enriched in alkalies and containing large crystals of augite (a complex silicate of calcium, magnesium, iron and aluminium), which stand out very prominently from the finer-grained body of the rock. Variations in the mineral composition suggest that two or more varieties of rock are present, enhancing the potential of the site for research.