Page:Quarterly Journal of the Geological Society of London, vol. 25.djvu/544

420 c. Glaciated Rock-surfaces near Ulverstone.—To the north of Ulverstone, between Arrad Foot and Penny Bridge, and near to a house called Gawith Field, I saw one of the finest specimens to be met with in this country of a broadly and regularly grooved surface. The flutings were on the whitened face of a block of dark grey porphyry which had been built into a wall. But the most extensively glaciated rock-surfaces in the Furness peninsula may be seen on the sea-coast between Bardsea and Baycliff. The Boulder-clay, locally called "pinel," has been stripped off the glaciated rocks by the sea. The striae run approximately N. and S., or between N. and S. and N.N.E. and S.S.W.; but in many places the lines cross each other at small angles in a very confused manner, as if the icy handle of the graving tool had moved unsteadily. Some of the boulders may be seen with striations crossing each other at angles amounting to 15°. In many places under the pinel the limestone-rock is not glaciated. These facts ought to be mentioned, as they bear more or less on the question of the origin of the pinel. Near Baycliff an observer, if he has not been forewarned, may become painfully acquainted with the most perfect specimen of a polished rock-surface perhaps to be found in this country. Over a number of square yards the compact limestone has received so high a degree of polish that no one can walk on it without running a great chance of falling.

d. Lower Boulder-clay or "Pinel " between Bardsea and Baycliff—Indications of stratification.—On the east coast of the Furness peninsula the sea has exposed a fine section of pinel which reaches the thickness of about 20 feet. It commences a short distance to the south of Bardsea, and extends with little interruption to the south of Baycliff. In some places it is little more than a confused mass of limestone-debris apparently torn up from the underlying-strata;in other places the stones are subangular; generally speaking they are more or less rounded, and occasionally as much so as ordinary beach-gravel. The stones are chiefly limestone, the same as the rock below; but many of them have come from the Silurian slate-district to the north. Sometimes the limestone, sometimes the Silurian boulders are the most rounded or the most angular, as if rounding did not depend on the distance travelled. In a few places there is the appearance of a line of demarcation between the hard or lower and the rubbly or upper part of the deposit, as if the latter represented the Upper Boulder-clay. Generally speaking, there is a well-defined line of separation between the pinel and the underlying limestone-rock, which is here and there, not everywhere, glaciated, as before remarked. The main character of the pinel may be describedas a mass of excessively hard yellowish-brown clay packed full of stones of various sizes, including numerous large boulders. In some places it would be more correct to call it a conglomerate or