Date of Award
Master of Science in Geology
The Nueces River in South Texas flows in a southeasterly direction toward the Texas Gulf Coast. In southeastern Lasalle County, the Nueces River makes an abrupt 90° turn and flows northeast for 56 miles. The Nueces River joins with the Frio and Atascosa Rivers to flow southeasterly, debouching in Corpus Christi Bay. It has been theorized that the Nueces River once flowed southeasterly crossing northeast Webb and central Duval Counties and then into Baffin Bay. The paleo-Nueces River is thought to have occupied the Las Animas and/or Parilla streams in Duval County. This study attempts to locate this ancient paleo-stream channel of the Nueces River.
A ground investigation including topographic maps, multispectral aerial photographs at various scales, along with Skylab photographs, and Landsat imagery, revealed no positive surficial expression of the paleo-system. A lineament study failed to depict any definitive structural control of the present course of the Nueces River. Termination of most electric well logs near the surface, resulted in a lack of data on Pleistocene or Holocene deposits to determine if a fluvial system did exist in the uppermost portion of the stratigraphic section. As a result, a lower stratigraphic sequence, upward from the Catahoula (Miocene) through the Goliad (Pliocene) was examined with emphasis on the Catahoula and Oakville Formations. If stacked bar and channel sequences beneath the proposed former course of the Nueces River exist in these older sediments, they will lend credence to the theory that the course of the paleo-Nueces River crossed Duval County.
Electric log data including the construction of five cross sections provided no definitive evidence of the Las Animas and/or Parilla streams superposing a paleo-Nueces River. Construction of a sand dispersal system of the Oakville and Catahoula Formations included maximum sand, net sand, and percent sand lithofacies maps. These lithofacies maps depicted a sandy fluvial system, during Catahoula time (only) superposed by the Las Animas stream.
If the Nueces River ever followed the Las Animas and/or Parilla stream drainages, it did so during post Goliad (Pliocene) times but prior to the uplift of the Bordas escarpment. These sandy fluvial systems that have been delineated may be potential host rocks for uranium concentration.
Daub, Gerald Jacob, "Stratigraphic Interpretation of a Possible Paleostream Channel of the Ancient Nueces River, South Texas" (1979). Open Access Master's Theses. Paper 2071.
Figure 7: Cross Section Map (Well Locations Used in Cross Sections A-A', B-B', C-C', D-D', E-E'
thesis_daub_gerald_1979_Fig8.pdf (187 kB)
Figure 8: Catahoula and Oakville Data Points
thesis_daub_gerald_1979_Fig15-c.pdf (1806 kB)
Figure 15-C: NE-SW Cross-Section
thesis_daub_gerald_1979_Fig19.pdf (204 kB)
Figure 19: Net Sand of the Catahoula Formation
thesis_daub_gerald_1979_Fig20.pdf (173 kB)
Figure 20: Maximum Sand of the Catahoula Formation
thesis_daub_gerald_1979_Fig21.pdf (207 kB)
Figure 21: Sand Percent of the Catahoula Formation
thesis_daub_gerald_1979_Fig22.pdf (176 kB)
Figure 22: Net Sand of the Oakville Formation
thesis_daub_gerald_1979_Fig23.pdf (170 kB)
Figure 23: Maximum Sand of the Oakville Formation
thesis_daub_gerald_1979_Fig24.pdf (178 kB)
Figure 24: Sand Percent of the Oakville Formation