Abstract: Evidence for Regional Cenozoic Denudation of the Ouachita Trend and Southern High Plains Based on Apatite Fission-Track Thermochronology

KELLEY, SHARI A.

A growing database of apatite fission-track (AFT) thermochronology results from the Ouachita trend and the Southern High Plains can be used to infer that 1 to 2 km of denudation has occurred in these areas since the middle Cenozoic. AFT data from the Anadarko Basin, Oklahoma, suggest that approx. 1.5 km of denudation has occurred since 40 to 50 Ma. AFT analysis of samples from the Arbuckle, Llano, and Marathon uplifts (Corrigan et al., 1997) and Wichita Mountains (Winkler, 1996) indicates that approx. 1 km of late Cretaceous to early Cenozoic sedimentary rock has been eroded from these uplifts since 25 to 50 Ma. This timing is roughly coincident with the development of the Rocky Mountain erosion surface in Colorado and Wyoming and the widespread mid-Cenozoic unconformity on the northern Great Plains. AFT data from the High Plains-Southern Rocky Mountain boundary of New Mexico indicate that denudation was in progress during late Oligocene to early Miocene time, resulting in removal of at least 2 km of section in eastern New Mexico. Possible mechanisms causing regional denudation include a drop in eustatic sea level, as well as climatic and tectonic factors. Elevated temperatures during burial prior to denudation has had an important affect on the level of thermal maturity attained in hydrocarbon-producing areas in the southern mid-continent. In addition, denudation may have altered the pressure and fluid flow regimes in basins of the southern mid-continent.

AAPG Search and Discovery Article #90946©1997 AAPG Rocky Mountain Section Meeting, Denver, Colorado