Glacial Lithogenesis

sedimentary rock development on areas of continents which are covered by glaciers. The low temperature in areas of glacial lithogenesis suppresses the activity of chemical processes and the vital activity of organisms. The material for sedimentation forms as a result of the mechanical crushing of rock that is not covered by ice and by glacial erosion. The crushed material is transported chiefly by the ice and only partly by the water (in the form of subglacial rivers). This leads to the absence of mechanical sorting and the absence of differentiation of the sedimentary material. As a result of glacial lithogenesis, rock containing more than 95 percent fragmentai components is formed.

Among deposits from past geological periods, products of glacial lithogenesis are encountered relatively rarely (for example, greatly altered morainic formations known as tillites).