Observations on the Yorkshire Drift and Gravel

Abstract

At the June meeting of this Society, I read a short paper on the occurrence of boulders of granite in the vale of the Calder, near Halifax, when I alluded to those deposits of clay with erratic boulders which are generally known by the appellation of Diluvium, or Drift. I have now to request your attention to a more particular inquiry into this formation, which is interesting both as indicative of considerable changes having taken place at a very recent geological period, and also from the great discussion and various theories to which it has given rise. The accumulations of removed matter which occur very extensively, not only in many parts of Great Britain and the northern countries of Europe, but also on the continent of America, under all circumstances maintain a great similarity of constitution—their general character being the assemblage of pebbles and boulders of the harder rocks (more or less rounded by attrition), dispersed amidst a mass of clay or sand, without any appearance of stratification or order. This confused disposition of the fragments has given rise to the idea that a force of such power has been required, as would overcome the specific gravity of the various component parts; and as the action of a vast deluge has been thought to be the only one which could explain the phenomena, the term Diluvium has been, till lately, generally recognized. In no part of Great Britain can this boulder formation be studied more effectively than in Yorkshire ...