Telescope Peak, California, USA
U.S. Geological Survey photo (fair use policy)
Telescope Peak is the highest mountain in Death Valley National Park, California. Death Valley has an undeserved reputationjust because the first party of outsiders to see it were starving and thirsty, they gave it the worst name they could think of. But the Shoshone people got along well with this bright, remote land, moving into the valley in winter and up its mountain walls in the hot season.
The valley is a place where the Earth's crust is stretched so thin that the surface lies below sea level. Geologists put this place on their life lists, especially those interested in the behavior of the middle and deep crust under extension. The differently colored bodies of rock in the side of Telescope Peak are bounded by faults, showing that they have slipped with the stretching crust like M&Ms spilling from a bag. That happens at great depths, whereas at the surface this kind of movement occurs along steeply dipping or vertical faults. Faults that change downdip from steep to shallow to horizontal, like the curve of a snow shovel, are called listric faults. The great degree of crustal extension here has revealed these deep details.
Where Death Valley is a great downdropped block or graben, Telescope Peak sits on the high part, or horst, that flanks the valley.