A vocabulary of landscape — a landscape of words
1068 entries
fault
A fracture in the earth’s crust along which rock masses have moved relative to each other — shifted, displaced, ground past. Faults range from inches long to thousands of miles. The San Andreas is a transform fault — two plates sliding laterally past each other. Normal faults pull apart; reverse faults compress. A thrust fault pushes older rock on top of younger, reversing the expected order of the geological record.
Etymology
Old French faute, a failing, a lack, from Latin fallere, to deceive, to fail. The geological sense dates to the 18th century, when miners noticed that ore veins could disappear at a fracture — the vein had “faulted,” failed them.