Turnberry Lighthouse to Port Murray

Site of Special Scientific Interest · 55.3303, -4.8381

Condition (NatureScot)

Favourable (1)
UnitFeatureConditionArea (ha)Assessed
F1 Old Red Sandstone Igneous Favourable 2009-02-20

Geology & landscape

Geological Period: Devonian · Rock Type: Andesite

Landscape processes: Volcanic / Igneous

Description

Turnberry Lighthouse to Port Murray From Turnberry Lighthouse to Port Murray a thick sequence of up to thirty basic andesite sheets, often strongly plagiophyric and ranging from two to twenty-five metres in thickness, are in places separated by siltstones and sandstones of Lower Devonian age (approximately 410 million years ago). The site has been historically important in the study of the Devonian lavas of Scotland and is notable for fine exposures illustrating the internal variation in the andesite sheets and the nature of their contacts. The latter are characterised by pillow structures, peperites (thermally shattered magma), and complex enclosures and veins of sediment. Recent research has demonstrated that the sheets, formerly thought to be subaerial lava flows, are sills emplaced at shallow depths into unconsolidated wet sediment.