Processes invoked to account for the undercutting include
(1) the presence of softer and more effortlessly weathered bands of rock;
(2) abrasion by windblown sand (cf. p. 317);
(3) salt weathering brought about by salts raised by capillary action from soil-covered talus at the cliff base;
(4) the intensified rotting of the sandstone by moisture rising from the soil or talus; and (5) subsurface weathering that occurs prior to footslope lowering.