Stile End

Also within

Cumbria County LAKE DISTRICT National Park

Condition (Natural England)

Geology & landscape

Geological Period: Ordovician, Silurian · Rock Type: Rhyolite, Siltstone

Landscape processes: Volcanic / Igneous

Description

Description The site consists of an area of hillside, crags and disused pits and quarries to the east of Stile End Farm above Kentmere. The Kentmere Longsleddale area is the only area where a complete sequence through the lowest part of the Dent Group of the Southern Lake District may be seen and the site contains representative sections through this sequence. The conglomerates, sandstones, siltstone and limestones exposed here are of importance in reconstructing late Ordovician palaeogeography of this area. The Longsleddale and Stile End Formations provide evidence firstly of a fluviatile transgression, followed by marine conditions. This took place over an uneven and eroded land surface representing the remnants of the Borrowdale Volcanic terrane. The Stile End Formation is conformably overlain by the Yarlside or Stockdale Rhyolite, considered to represent a submarine extrusive lava. This is conformably overlain by the Applethwaite Formation. All three formations are regarded as belonging to the Cautleyan Stage of the Ashgill Series. Both to the east and west of the Kentmere Longsleddale area there are rapid changes in the thicknesses and distributions of these formations. This has been attributed to the theoretical presence of a tectonically active positive area on the eastern side of the Lake District, the effects of which persist throughout the remainder of the late Ordovician and into the early Silurian. The Stile End Formation in this area has yielded the type material of a number of trilobites, as well as rich brachiopod and coral faunas. A key site for upper Ordovician biostratigraphical studies.