Page:Quarterly Journal of the Geological Society of London, vol. 33.djvu/843

Rh each occasion have seen fresh faces exposed by the rapidly encroaching sea, at intervals, along the whole cliff-line, which is about three miles in length. In every instance the

Line of Junction between the Lower and Upper Boulder-clays, whether straight or undulating, was so well defined as to suggest the idea that the surface of the lower clay had become either hardened or denuded before the upper clay was deposited. This line, in one place, appeared as represented in

Fig. 1.

Deposits at the Base of the Lower Clay.—At intervals in the lower clay there were pockets and layers of small stones, and likewise of sand. At the base, in several places, the clay graduated into, or became interstratified with beds of bright reddish brown sandy loam (without stones and with stones), which in one place exhibited a quaquaversal arrangement. I could see few or no shells in these loamy beds; and there was no appearance of an old sea-bed having been worked up into the substance of the clay above. There were no contortions, such as occur in the drifts all round the borders of the Lake-district. A few feet above the level of the beach the clay resumed its typical character. At Blackpool there are similar loamy beds on the same horizon relatively to the lower clay (Quart. Journ. Geol. Soc. vol. xxv. p. 412).

Character of the Striated Erratic Stones.—On the day above mentioned I saw many kinds of erratic boulders and smaller stones I had not previously noticed. Next to "greenstone," Criffell granite was again found to predominate, but in greater variety, including the grey kind with large, sharply defined crystals of felspar, and the reddish-brown kind (resembling Shap granite). Granite of the kinds now quarried in the neighbourhood of Creetown, Kircudbrightshire, were represented, especially the white Fell granite. Most of the stones, both small and large, were striated as follows:—

1. Irregularly scratched all round (by land-ice before they were transported?).

2. Irregularly scratched all round, with the addition of superinduced flattened surfaces and single or cross sets of parallel grooves.

3. Merely flattened surfaces, with single or cross sets of parallel grooves.

The grooves run in all directions relatively to the longer axes of the stones, including large boulders. They are so fresh-lcoking and cleanly cut as to suggest the idea that the stones were not re- transported or jostled about after the grooves were imprinted. The uniformly flattened surface, and the character of the grooves, would both seem to point to rapidity of movement in the glaciating agent.