|Source: National Park Service|
Our students had just learned about these four basic fault types at the Charlie Brown outcrop, but they were looking at fault planes in a roadcut. As we entered Death Valley, we started seeing the effects of recently active faults on the landscape. We stopped along the road near a couple of odd features that don't really make sense on a valley floor where deposition should be the dominant process. It was a particularly instructive spot, as we could see evidence of movement along two kinds of faults from one viewpoint.
At this point we are below sea level on the floor of Death Valley, a 100+ mile-long fault trough. Mountains rise high on both sides of the valley, with a total relief of more than 11,000 feet (few places on the continent can claim such extreme elevation changes over so short a distance). Such fault valleys are termed grabens (the German word for grave or trench), while the mountains are termed horsts (German for eagle's nest or aerie).
Aztec Sandstone at Red Rock Canyon here. These faults are not currently active.