Page:Quarterly Journal of the Geological Society of London, vol. 26.djvu/729

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granite over the Cumberland plain and in the valley of the Eden. The southern current is not so clearly indicated ; still the absence of Wastdale-Crag blocks from the valley of the Lune to the south of Wastdale Crag supports, to some extent, the supposition of its existence*.

The combined influence of a northern and a southern current with land to the westward would give rise to a current having nearly an eastern course ; and a current having such a direction would carry ice-sheets loaded with blocks over Stainmoor.

The existence of water at or near such a high level, at or immediately after the period of the transportation of Wastdale-Crag blocks, is shown by the occurrence of Eskars, which have been already alluded to as making their appearance near the east base of Wastdale Crag.

These are seen in some spots at a height of about 1100 feet above the present sea-level; they exhibit a great amount of false-bedding, and they are seen scattered over a moor in positions where no river-action could have operated to produce them.

Professor Phillips, in a communication to the British Association (Report, 1864), expresses an opinion that the distribution of the Wastdale-Crag blocks " cannot have been performed by ice-flotation in an ocean, however elevated, if the present relative elevations of the country were the same as now." Judging from the age of the valleys in Westmoreland it would, however, appear that this relative change of level, if it has taken place at all, could not have been of such a character as to give rise to the present general outline of the country. Some slight relative changes may have taken place on one side or other of the great Permian fault, but no such change as could have materially affected the general contour of the district east of Wastdale Crag.

Even had such changes of level taken place on opposite sides of the Pennine fault, there would still be the difficulties which arise when we consider the surface -outline of Westmoreland, over which the blocks have travelled, to be overcome.

Reference has been made to the Boulder-clay of Westmoreland ; and in this Boulder-clay it has been shown that no Wastdale-Crag blocks occur. As the Pleistocene formation, in some parts of England and Ireland, exhibits three well-marked periods, — namely, first and lowest, Boulder-clays, resting on sands and gravels which possess an Arctic fauna ; second, gravels, sands, and marls marked by a fauna of a less Arctic character ; and third, another Boulder- clay which, in the valley of the Clyde and elsewhere, is capped by beds containing shells also of Arctic types, — the inquiry naturally occurs, To which of these series are we to assign the Boulder-clays of Westmoreland upon which Wastdale-Crag blocks are found ?

Observations induce the conclusion that of these members of the Pleistocene group the two former, namely, the lower Boulder- clays,

  • Blocks of Wastdale-Crag granite are seen on the western side of the Lune,

about Selside, six miles due south of Wastdale Crag.