footwall

The lower-lying side of a reverse (compression) fault is called a footwall. The rock mass that towers above the footwall is called a hanging wall. These terms were first used by English miners working such faults: they stood on the footwall and hung their lamps from the overarching hanging wall. With a normal (tension) fault, though, it’s the higher side of the inclined fracture that’s called, somewhat incongruously, the footwall and the lower side that’s called the hanging wall.

Donna Seaman