Geology of the Abbeystead area, (SD 55 SE) : part of 1:50,000 Sheets 59 (Lancaster) and 67 (Garstang)

Abstract

This report describes the geology of BGS 1-10,000 Sheet SD 55 SE, part. of the 1:50,000 Sheets 59 (Lancaster) and 67 (Garstang). The area was first mapped by R.C. Tiddemann on the scale of 1:10,560, and was published on the Primary Series Sheets 91 NE and 91 SE in 1884. The present survey was carried out between 1984 and 1986 by R.A. Hughes, E.W. Johnson, and A. Brandon, under the supervision of Dr A.J. Wadge, Regional Geologist. The southern two thirds of the area was mapped by R.A. ijughes, and the northern third (including the important sections of the River Wyre and its tributaries) by Drs Brandon and Johnson. Approximately the southern third of the area is peat and heather covered moorland, used only for sheep grazing and grouse shooting. Hawthornthwaite Fell Top [5790 5148] is the highest point at 478 m, and lies on the watershed of the Bowland Fells. To the south-west of here the land drains into the headwaters of Langden Brook. To the north-west of the watershed the land drains into the River Wyre. The remainder of the area is relatively lower-lying and flat, and is used for pasture and for growing fodder crops. The northern part of the area is incised by the westerly flowing River Wyre and its tributaries. (The Marshaw Wyre and the Tarnbrook Wyre join at Abbeystead to form the River Wyre). The area contains the southern end of the Wyresdale tunnel, the geology of which was described by Johnson (1981). The southern portal of the tunnel was the site of a fatal explosion in May, 1984. The mapping of the northern third of the sheet was a response to the demand for detailed geological information for use in the ensuing public enquiry. The results of this work are presented in Wilson, Brandon, and Johnson (1985). The only other work in the area is in the extreme north-west of the sheet, which was mapped by Moseley (195