IV.—Subsoil Denudation of Boulder-Clay

Extract

On removing the superficial sand and soil to prepare for getting clay for brick-making, it is not unusual to find the surface of the Boulder-clay in this neighbourhood corrugated with tortuous channels. These channels are commonly filled with slutchy sand and gravel, which must be removed before the clay can be obtained.

At the present time there is an excellent example to be seen in Earle Eoad, Smithdown Road, Liverpool, next to the site of a new Board School that I am, as architect, superintending. The surface of the ground slopes rather quickly to the valley below, and the superficial strata consist of soil and a yellow subaërial quartzose sand, together from 4 to 5 feet deep, in which there are no stones or gravel. This sand we are using for mortar, it being what is called “sharp,” or consisting of angular grains. Below this the corrugations of the Boulder-clay are better developed than I have seen elsewhere, and give a clue to the origin of these channel-like depressions.