Ash Fell Edge

Also within

Cumbria County YORKSHIRE DALES National Park

Condition (Natural England)

Geology & landscape

Geological Period: Carboniferous · Rock Type: Carboniferous Limestone, Limestone, Sandstone

Description

Area, 8.4 ha. 20.7 ac. Description This site occupies a south west facing slope near the crest of Ash Fell, 1g kilometres northeast of Ravenstonedale. It straddles the A685, Tebay to Kirkby Stephen road, the cutting of which forms an important part of the site. The geological interest of the site, in technical terms, may be defined as follows: Ash Fell Edge is a nationally outstanding Lower Carboniferous locality, being the type locality, probably the best exposure and certainly the thickest development of the Ashfell sandstone and Ashfell Limestone Arundian Holkerian Stages. These units are of importance in elucidating the development of the 'Stainmore Trough' and the shallow water sedimentation which occurred in it during Dinantian times. This is one of Garwood’s classic faunal localities, the preservation of fossil material from here being second to none. Growth rings on superbly preserved Ash Fell coral specimens have been used to determine the length of the Lower Carboniferous year. This is in all, a key locality for its famous fossil faunas and its bearing on Carboniferous paleogeography, stratigraphy and sedimentation. In layman’s terms the interest of the site may be expressed more simply and such a statement is provided below. The road cutting and old quarries at this site provide the most important outcrops of two of the major formations within the Carboniferous Limestone of the region. These outcrops have provided geologists with important evidence concerning the mode of origin of these rocks which accumulated as sand and lime on the floor of a shallow sea about 345 million years ago. The rocks here are also important as the source of a variety of extremely well preserved fossils, remains of the animals that flourished in the Lower Carboniferous sea.