South Texas Quaternary karst: Paleoclimatic implications

Conference · Mon Feb 01 04:00:00 EST 1993 · Geological Society of America, Abstracts with Programs; (United States)

OSTI ID:5976270

Prouty, J S ^[1]; Lovejoy, D W ^[2]

---

1. Corpus Christi State Univ., TX (United States)
2. W. Palm Beach Atlantic Coll., FL (United States)

A beachrock correlative with the Ingleside complex of the late Pleistocene Beaumont Formation crops out discontinuously along the mainland shore of Laguna Madre, extending approximately 10 km southward from Baffin Bay, Texas. Carbon-14 dating yields ages of 23, 430 to 33,390 yrs. B.P.; the beachrock formed along a Gulf shoreline in a zone of converging longshore currents during the last sea level highstand of the late Wisconsinan. The beachrock shows intense karstification. Vertical, steep-walled solution pipes penetrate the outcrops, and reddish-brown laminated caliche crusts coat outcrop surfaces and solution-pipe walls in many places. These karst features probably formed by subaerial exposure and weathering of the beachrock during the latest sea level lowstand. Today in semiarid South Texas, rainfall averages only 28 inches per year. Local features of late Pleistocene age include river gravels coarser than modern loads of those same rivers, and relict drainage networks far denser than modern ones. Such features indicate that during the late Pleistocene this region was more humid than now. Karst is typical of humid to subhumid climates, also suggesting that during karstification of the beachrock wetter climates prevailed.

• OSTI ID: 5976270
• Report Number(s): CONF-9303212--
• Conference Information: Journal Name: Geological Society of America, Abstracts with Programs; (United States) Journal Volume: 25:1
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580000* -- Geosciences
AGE ESTIMATION
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CARBON 14
CARBON ISOTOPES
CAVES
CAVITIES
CENOZOIC ERA
CLIMATE MODELS
DEVELOPED COUNTRIES
DISSOLUTION
EVEN-EVEN NUCLEI
GEOLOGIC AGES
GEOLOGIC FORMATIONS
GEOLOGIC HISTORY
ISOTOPE DATING
ISOTOPES
LIGHT NUCLEI
MATHEMATICAL MODELS
NORTH AMERICA
NUCLEI
PALEOCLIMATOLOGY
PALEONTOLOGY
PLEISTOCENE EPOCH
QUATERNARY PERIOD
RADIOISOTOPES
TEXAS
USA
YEARS LIVING RADIOISOTOPES