Boulder clay

BOULDER CLAY (EN: boulder clay, till, drift clay; DE: Geschiebelehm, Geschiebeton; FR: argile à blocaux; ES: arcilla en bloques, arcilla glaciar; RU: валунная глина) is the clay of the glacial origin, which represents by itself the mixture with the clays, aleurite, sand, gravel, debris and boulders of the rocks with the different sizes. There are characteristic for the boulder clay: the gray and brown colouration, the absence of the layering, sometimes the thin-layer horizontal separateness (as the consequence of the pressure from the glacier). The clayish substance consists mainly of hydromica and chlorite, with the admixture of kaolinite and montmorillonite. The boulder clays are widely distributed within the northern European part of the USSR. The deposits with the boulder clay are being developed mostly for the needs of the brickwork plants.