slgwv's photos with the keyword: fault

Looking west from Nevada State Route 121 in Dixie Valley, central Nevada. The prominent break in slope running roughly horizontally across the middle of the picture marks the trace of the range-front boundary fault, where the Stillwater Range is being uplifted with respect to Dixie Valley. The slope above that break is the fault-plane surface, little modified by erosion. Big Box Canyon (outlined) is a slot canyon that's incised into the range front. The downcutting by the stream is more or less keeping pace with the uplift, but the canyon remains narrow because the erosion is (geologically!) happening so quickly. The tapering downward canyon cross-section ("wineglass") is characteristic of streams cutting across active high-angle faults. Faulting here is ongoing: a huge earthquake in December 1954 (~Richter 7.4) left a ~15 ft (~ 4 m) scarp along much of the range front. It's barely visible here, but is much more prominent elsewhere. This area lies in the Central Nevada Seismic Belt, a north-south trending zone that's been the site of other large historical earthquakes.

Extending east, almost linearly, from the currently active spring. It appears that a fault or fissure localized the spring.

Somewhere along the Cuddy Valley road, looking east--location is as best as I can remember, but someone who recognizes the area feel free to comment! San Emigdio Mountains on the left. This valley is the trace of the San Andreas fault, and I'm sure that not one in a hundred of the people living in the slew of vacation homes and such along here know they're sitting right on top of the fault. This was where the enormous 1853 Ft. Tejon quake occurred, estimated at >8.0 based on contemporary accounts. Geology in action!

Yes, this is it--the famous San Andreas Fault in southern Californa, boundary of the North American and Pacific Plates. The fault zone runs generally from lower right to upper left. The most currently active trace is parallel to the range front but out in the valley, beyond those low hills on the right. The light-colored rock in the center is sandstone units called the Devil's Punchbowl, a county park. The prominent drainage at lower right-center is Big Rock Creek. The mountains bulking up at the left are the San Gabriel Mountains, which are fault bounded--an uplifted block, in fact--and define the northern boundary of the Los Angeles Basin. The low country visible out to the upper right is part of the Mojave Desert. Seen looking northwesterly from CA State Route 2, the Angeles Crest Highway. It's a remarkably scenic route that doesn't fit most images of SoCal!

Red Rock Canyon Recreation Area, southern Nevada. The upper part of Red Rock Wash follows the swale in the upper center of the photo. It marks the trace of the Keystone Thrust, where gray Paleozoic limestones have been shoved over the light-colored Aztec Sandstone to the east. The thrust also continues to the south, parallel to and near the road I'm on. The thrust is parallel to the Red Rock escarpment, which is off the photo to the left (east), on the other side of the sandstone outcrops The road I'm on, the Rocky Gap road, is a barely passable Jeep track, still open to motorized traffic, that goes through Willow Spring gap in the Red Rock escarpment along Red Rock Wash, and then south behind the escarpment up a steep canyon. It eventually exits into Lovell Canyon road and the Pahrump highway. However, structures like stonework around culverts indicate this road was once in much better shape, and it may have been a CCC (Civilian Conservation Corps) project from the 1930s.

Classic example of a fault-defined range front, with a linear break in slope and triangular-faceted ridges coming down to it. View from just off US 95 looking southeast.