Smithwick quadrangle, Texas

OFM0216. Geologic Map of the Smithwick Quadrangle, Texas, by C. M. Woodruff, Jr. Oversize geologic map on a color topographic base, map scale 1:24,000, 2014. Paper map. For a PDF download: OFM0216D.


About This Publication
The Smithwick Quadrangle of Burnet County straddles the Colorado River along the impounded upper reaches of Lake Travis. Quaternary alluvial deposits (sand, gravel, silt, and clay) occur as terraces above lake level and as discontinuous valley deposits along tributary streams. The map shows a major unconformity between Cretaceous and Paleozoic strata. Cretaceous units in this area include: Sycamore Sand, Hammett Shale, Cow Creek Limestone, Hensel Sand, Glen Rose Limestone, discontinuous Paluxy Sand, Walnut Formation, Comanche Peak Limestone, and Edwards Limestone. Pennsylvanian strata (Smithwick Shale, Smithwick Sandstone, and Marble Falls Limestone) directly underlie the Cretaceous section. In places, these Paleozoic rock units are displaced by normal faults that trend northeast–southwest and locally juxtapose the upper Paleozoic strata against lower Paleozoic units (Ordovician Ellenburger Group and Cambrian San Saba Limestone).


Keywords: Burnet County, maps, geologic maps, Smithwick Quadrangle, Sycamore Sand, Hammett Shale, Cow Creek Limestone, Hensel Sand, Glen Rose Limestone, Paluxy Sand, Walnut Formation, Comanche Peak Limestone, Edwards Limestone. Pennsylvanian, Smithwick Shale, Smithwick Sandstone, Marble Falls Limestone, Texas


Citation
Woodruff, C. M., Jr., 2014, Geologic Map of the Smithwick Quadrangle, Texas: The University of Texas at Austin, Bureau of Economic Geology, Open-File Map No. OFM0216, map scale 1:24,000.