Turtleback'' structure in the southwestern Panamint Mountains, Death Valley region, California
- Univ. of Southern California, Los Angeles, CA (United States). Dept. of Geological Sciences
The western range front of the Panamint Mountains south of Ballarat is a partially exhumed fault surface, dipping 15--25[degree] W, as first noted by Curry (1938), who named this type of structure a turtleback''. Mapping (1:4800) demonstrates that along lower slopes of the range late Cenozoic fanglomerate is in fault contact with metamorphic bedrock. The shallow-dipping fault at the base of the fanglomerate is very sharp and gouge is present along it. Structural contouring of the fault shows that it is very planar and that its average strike and dip are N 03[degree]W and 20[degree] W, respectively. If this contact were an unconformity, as previous workers have interpreted it, it would be rougher, displaying the paleotopography of an eroded bedrock surface. Brecciation of lower-plate metamorphic rocks extends for several meters to a few tens of meters below the fault. The brecciated zone is stained red by iron oxides, unlike the overlying fanglomerates. This zone is probably a fault zone, and is present over much of the turtleback surface, extending 0.5 to 1.5 km higher on that surface than the fanglomerate. The fault-controlled development of the western Panamint range front has had at least three stages of development: A possible first stage, uplifting the range block via west-directed extension, a stage of continued uplift of the range block relative to the fanglomerate, and a period of Quaternary right-oblique( ) slip.
- OSTI ID:
- 5342483
- Report Number(s):
- CONF-9305259-; CODEN: GAAPBC
- Journal Information:
- Geological Society of America, Abstracts with Programs; (United States), Vol. 25:5; Conference: 89. annual meeting of the Cordilleran Section and the 46th annual meeting of the Rocky Mountain Section of the Geological Society of America (GSA), Reno, NV (United States), 19-21 May 1993; ISSN 0016-7592
- Country of Publication:
- United States
- Language:
- English
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