On the Glacial Drift of Furness, Lancashire

Abstract

The following sketch of the glacial deposits of Furness is not pretended to be complete ; it is, in fact, nothing but a sketch: neither can it presume to be free from errors. The marine drift, especially, has not received all the attention it demands, but will, I hope, with the clays and peats of Furness, form a subject for a future memoir. The deposits in the section are referred doubtfully to their periods.Striated Bock Surfaces.—The district of Furness; its south-eastern part, however, does not perhaps present so many of those remarkable records of the glacial period, the striated rock-surfaces, as are to be met with in more mountainous districts. The rocks, especially the Carboniferous Limestone and Permian formations, either lie in agreat measure hidden under a thick covering of deposits, or, as in the hills of the Upper Silurian strata, are of such a soft decomposing nature, that they retain very little primitive facing.Occasionally, however, striations may be found. A little way in shore, west from the estuary of the Crake, at the head of Morecambe Bay, a rock-surface recently exposed by the removal of the overlying material, and now quarried away, showed a series of parallel shallow groovings from an inch to an inch and a half apart; the intervening spaces plane and smoothed, and having very fine striæ. The striæ and grooving had a direction from E. to W., or perhaps a little N.E. to S.W.