Late Quaternary highstand and transgressive deltas of the ancestral Colorado River: Eustatic and climatic controls on deposition.

摘要

Deltaic deposits were the main sinks for sequestering large volumes of sand on the northern Gulf of Mexico continental shelf during the late Quaternary. Examination of high resolution seismic reflection data, cores, and platform boring descriptions allows detailed description and delineation of two sand units on the East Texas shelf. This study determined sand source, depositional setting, and volume of each unit along with an evaluation of sediment supply changes through time.;The ancestral Colorado River deposited the two deltaic sand units during a sea-level highstand (Stage 3) and a sea-level rise (Stage 2 to 1). The balance between sediment supply and eustasy controlled the timing and style of delta deposition. Climate changes in the drainage basin have tentatively been correlated with sediment supply changes. Generally, increased supply up-dip correlates with increased yield down-dip, however, other factors, such as floods and floodplain construction, can modify the overall signal.