A GUIDE TO THE GEOLOGY OF THE CLIVIGER VALLEY, NEAR BURNLEY, LANCASHIRE

Abstract

I. Introduction The Cliviger valley or gorge is a prominent feature near Burnley in Lancashire, trending in a south-easterly direction to Todmorden in the West Riding of Yorkshire. The valley is about six miles in length, followed by a railway and a road (A.646). Some four miles from Todmorden, near Windy Bridge, two streams rise, the Lancashire and Yorkshire Calders, and flow in opposite directions to the Irish Sea and to the North Sea. The area described is bounded on the north-east by the Long Causeway as far as Redmires Dam ( 930277 ) and thence to Hole Bottom and Todmorden. The limit on the south-west extends along the summits of Carr and Craggs Moor ( 895255 ), Heald Moor ( 885265 ), Thieveley Pike ( 872272 ), and Crown Point ( 849288 ). The valley is a striking feature, in parts of rugged aspect, and is some 500 feet deep at Windy Bridge, with a canyon-like section—the effect of its former utilisation as a direct glacial overflow channel. It has thus been over-deepened and consequently the tributary streams enter it in a series of gorges with characteristic rejuvenation phenomena; the streams are actively eroding their beds and provide good natural sections except where the valley sides are obscured by landslips. These deep V-shaped valleys contrast greatly with the somewhat featureless expanses of the surrounding moors, although they are rarely mentioned in the general descriptions of the Central Pennines. The beds of the Millstone Grit Series give rise to a fairly continuous escarpment along the south-west side of the …