Geologic Map of Mariscal Mountain, Big Bend National Park, Texas

MM0048. Geologic Map of Mariscal Mountain, Big Bend National Park, Texas, by P. W. Dickerson, W. R. Muehlberger, and E. W. Collins. Oversize color map, scale 1:24,000, 2010.


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About This Publication
The Mariscal Mountain area is located in the Rio Grande bend, in southernmost Big Bend National Park. It straddles the border between Texas and Coahuila, Mexico. 

Portrayed in this geologic map as well as in four cross sections and selected field photos, are the results of at least eight tectonic and magmatic events that occurred in this area in Cretaceous and post-Cretaceous time. Principal observations: (1) Post-K rhyolite and basalt are thrust faulted in the nose of the Mariscal anticline. (2) A range-parallel thrust fault in central Mariscal Canyon is cut by north- and west-striking normal faults. (3) A major left-lateral strike-slip fault and probable flower structure are exposed in the east-central Canyon. (4) Previously unmapped rhyolite ignimbrite and Del Carmen Formation (oldest Cretaceous rocks in the park) are now documented. (5) Solution-collapse features are common in folded, faulted, and fractured Lower Cretaceous carbonate rocks—Boquillas Formation and rhyolite sills have foundered into one approximately 0.3-km sinkhole on the eastern mountain flank.

The map was compiled using field and aerial-photograph interpretations and with the assistance of staffers from the National Park Service and Bureau of Economic Geology and Department of Geological Sciences at The University of Texas at Austin. It is the first geologic map of the area to be constructed on a topographic base.


Keywords: maps, geologic maps, Big Bend National Park, parks, national parks, Mariscal Mountain, San Vicente Mountain, Texas


Citation
Dickerson, P. W., Muehlberger, W. R., and Collins, E. W., 2010, Geologic Map of Mariscal Mountain, Big Bend National Park, Texas: The University of Texas at Austin, Bureau of Economic Geology Miscellaneous Map No. 48, map scale 1:24,000.