Posbury Clump

Site of Special Scientific Interest · 50.7675, -3.6820

Also within

Devon County

Condition (Natural England)

Unfavourable Declining (1)
UnitFeatureConditionArea (ha)Assessed
SX814977 Unfavourable Declining 1.78 2010-03-18

Geology & landscape

Mining / Industrial: Quarry · Geological Period: Permian

Landscape processes: Volcanic / Igneous

Description

Posbury Clump SSSI Description This site exposes potassium-rich lavas of Permian age, the lavas being massive amygdaloidal trachybasalts with an irregular rubbly top to the lava flow. This is one of the few localities where the extrusive environment of the Permian lavas can be demonstrated. Part of the quarry is in an intimate sediment-lava “melange” with interrelationships that suggest the lava flowed over and penetrated wet sediments, variously entrapping baked sediment within an open lava network.