Hiking through the footwall. Cretaceous granitic rocks are cut by Tertiary mafic dikes (click for larger picture)

Tertiary volcanic rocks of the hanging wall above brecciated Proterozoic footwall gneiss (click for larger image)

Cataclasite in the Chemehuevi fault. Clasts are rounded and the fault gouge is moderately foliated (click for image)

Panorama showing the Miocene Peach Springs Tuff in the hanging wall and Proterozoic gneiss in the footwall. The low-angle nature of the fault (dashed line) is clearly seen from this vantage point.

On our second day camped in the Devil's Elbow wash, we hiked through fantastic footwall exposures to the Chemehuevi detachment fault at the point where it truncates the Devil's Elbow fault. The footwall to the Chemehuevi fault is always either Cretaceous or Proterozoic crystalline rocks; the hanging wall is variably composed of Cretaceous crystalline rocks or Tertiary volcanic and sedimentary rocks.

A spectacular overlook of the Chemehuevi detachment fault. The picture was taken from atop the (green) Proterozoic gneiss, which is intruded by the light-gray Cretaceous granite on the left. The red Tertiary hanging wall rocks stand out in stark contrast.