Page:South African Geology - Schwarz - 1912.djvu/116

1000 ft. above the floors. In other fault pits, in Oudtshoorn, Robertson, Swellendam, Riversdale, and Heidelberg, the loose gravels still fill the fault pits up to the brim, and the extraordinary case occurs that a more or less circular hole has been, as it were, punched in the

Fig. 33.—Map of the Mimosa area, showing the Fault letting down the Cretaceous beds

1, Basalt. 2, Tuff. 3, Dwyka conglomerate. 4, Witteberg quartzites. 5, Enon conglomerate. 6, Wood bed. 7, Alexandria beds. 8, Alluvium.

earth's crust, and a plug of rock foreign to the neighbourhood has been inserted, just as a carpenter might fill in a hole with a plug of wood.

Reversed faults are folds that have broken across the axis, and have allowed one side to be thrust over the other. The plane of fracture is not a fault plane, properly speaking; it is a thrust plane, and the reversed fault is more properly called a thrust fault, or simply