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Open-File Report 2004–1430

Geologic Map Compilation of the Upper Seco Creek Area, Medina and Uvalde Counties, south-central Texas

By Charles D. Blome1, Jason R. Faith2, Edward W. Collins3, Diana E. Pedraza2, and Kyle E. Murray4

1 U.S. Geological Survey, Denver, CO 80225
2 U.S. Geological Survey, San Antonio, TX 78249
3 Bureau of Economic Geology, University Station, Austin, TX 78713-8924
4 University of Texas at San Antonio, San Antonio, TX 78249-1130
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Version 1.0

Published 2005

This digital geologic map compilation presents new polygon (map unit contacts) and line (faults) vector data for the Seco Creek area in south-central Texas. The map database, which is at 1:50,000-scale resolution, provides geologic coverage for an area located in Medina County about 25 km northwest of San Antonio. The map area is underlain by sedimentary rocks of Cretaceous and Quaternary age that are offset by a series of normal faults. The stratigraphy ranges from the Lower Cretaceous Glen Rose Limestone (oldest) to Quaternary (youngest) alluvium. Edwards Group rock units are represented by the Devils River and Fort Terrett Formations, the latter being equivalent to the lower part of the Devils River Formation. The impetus for compiling the geology of the four 7.5 degree-quadrangle (Comanche Waterhole, Flatrock Crossing, Sabinal NE, and Texas Mountain) area was to provide a digital geologic map database for a helicopter electromagnetic (HEM) survey flown in 2002 and for ongoing 3-D EarthVision modeling of the Edwards/Trinity aquifer boundary.

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Digital geologic map for viewing and printing.
Text-only version of map report.
(This version of the report is accessible as defined in Section 508.)
Information to accompany the digital geologic map.
(This version of the report is accessible as defined in Section 508.)
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