EARTH PILLAR, a column of soft rock, or earth, which has not a homogeneous structure throughout, but contains large blocks embedded in much finer material. By exposure to con ditions of denudation, especially rain action, the large blocks protect the material beneath and so, by differential action, the earth pillars are produced. Glacial drift and morainic deposits are ideal substances in which earth pillars can be formed and these structures are therefore found in regions of recent glacia tion. Excellent examples are seen in Tirol and other parts of the Alps, in Scotland and in North America.