Evidence for Paleolake Rawtenstall around Stacksteads, Upper Irwell Valley, Rossendale, U.K.

Delaney, CA and Sikora, O (2016) Evidence for Paleolake Rawtenstall around Stacksteads, Upper Irwell Valley, Rossendale, U.K. North West Geography, 16 (1). ISSN 1476-1580

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Abstract

This paper presents new geomorphological and sedimentological evidence relating to the glaciation of the Upper Rossendale Valley, northwest England. We identify a previously unrecognised esker and associated glaciofluvial deposits within the valley, using high-resolution hillshaded Digital Terrain Models (DTMs) constructed using LiDAR data. A temporary exposure in a subaqueous outwash fan indicates the operation of an efflux jet from a conduit exiting an ice margin in the vicinity of theThrutch (Stacksteads) Gorge. We propose that the gorge was formed primarily by incision due to the drainage of the ice-dammed paleolake Rawtenstall during a previous glacial phase, but later operated as a subglacial meltwater channel after a local readvance of ice during the last Glacial Termination. A similar approach in other areas is likely to improve our detailed understanding of glaciation in the North West.