The subject of drifted boulders has latterly very much engaged the attention of geologists, and as there is great diversity of opinion regarding the means by which they have been removed into their present situations, every additional fact which may throw light upon the subject is valuable. I was therefore much interested in hearing from Dr. Alexander’s paper on the geology of the parish of Halifax, that in prosecuting the works on the line of railway, some blocks of granite had been found near Hobden-bridge, and this has led me to an examination of the bed of the river Calder, at Cromwell Bottom, about eight miles below the above-mentioned locality.
At this place the valley expands considerably in width, and the river, winding from side to side, exposes a good section of the strata through which it passes. The stream has cut through a deep alluvial soil, about six feet in thickness, beneath which is a bed of large pebbles, containing some boulders of considerable size, the majority of which are of coarse-grained sandstone from the millstone grit series, but mingled with these are many rounded fragments of granite and other crystalline rocks, whose original site is far distant. Some years since, the foundations of a mill were laid upon this gravel bed, hut on its proving insecure, the gravel was found to be only a few feet in thickness and to be succeeded by a stratum of a soft peaty nature, so deep that a twenty feet pile did ...
- © Yorkshire Geological Society, 1839-42