Origins of Mountains - Mountain Geography: Physical and Human Dimensions - page 49

California is a graben that lies 86 m (282 ft) below sea level between two horsts, the
Panamint and the Black Mountains of the Basin and Range geomorphic province.
FIGURE 2.18 Progressive development of fault-block mountain ranges. (A) Before faulting: The folds
and intrusion of a granitic pluton during a mountain-building orogeny have been followed by
erosion. (B) After block faulting: The tilted fault-block and horst mountains have been further
eroded to produce sedimentation into the graben valley and nearby lowlands. (After Plummer et
al. 2003.)
FIGURE 2.19 Systems of tensional normal faults commonly are characterized by a main fault with
subsidiary faults and by low-angle detachment faults with imbricate fault blocks on the upper,
hanging-wall block. Curved listric detachment faults that are gravity driven can move rapidly and
may even resemble giant landslides. All such complex fault systems can produce a variety of sur-
ficial structural landforms. (After Twiss and Moores 1992.)