Description and Quaternary History of the Campo Grande Fault of the Hueco Basin, Hudspeth and El Paso Counties, Trans-Pecos Texas


The Hueco Basin of Trans-Pecos Texas and Chihuahua, Mexico, formed in response to Basin and Range extensional tectonism that began about 24 million years ago and continues to the present. The southeastern arm of the basin is asymmetrical, with the thickest sediments deposited along the fault-bounded basin axis near the southwestern flank. Approximately 45 kilometers long and striking northwestward, the Campo Grande fault is 12 kilometers from the northeastern basin edge; it divides the downthrown central part of the basin (with over 2,000 meters of fill) from the shallower (175 meters) northeastern flank. Another major northwest-striking fault dips northeastward and bounds the southwestern basin margin in Mexico.

The Campo Grande fault trend is composed of at least 17 en echelon fault strands that are 1.5 to 10 kilometers long, with strikes of N25° to 75°W. Dips range between 60 and 90° southwest. Displacements decrease near the terminations of strands. Grooves on fault planes indicate mostly dip-slip movement. Fault scarps have been modified by erosion of the footwall and deposition on the hanging wall. Erosion-resistant caliche (stages IV to V) at the surface aids in preserving scarp heights ranging from 1.5 to 11.5 meters and scarp slopes of 4 to 17°.


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