John B. Anderson¹, Carmen M. Fraticelli¹, Jullia Wellner¹, Phil Bart², Heather Anderson², Ken Abdulah³, Laura Banfield⁴, Sabrina Sarzalejo⁵

(1) Rice University, Houston, TX
(2) Louisiana State University
(3) Conoco
(4) BP Amoco
(5) Inevep

ABSTRACT: Diachronous Response of Late Quaternary Deltas of the Northern Gulf of Mexico to Eustasy and Climate Change

High-resolution seismic data, sediment cores and oil company platform borings were used to study the evolution of the Appalachicola, western Louisiana, Brazos, Colorado and Rio Grande deltas during the last glacial eustatic cycle (125,000 years to present). The setting of these deltas varies in terms of climate; drainage basin size, gradient and geology; shelf gradient and subsidence; and long-term sediment yields of the rivers. All of the rivers delivered much greater quantities of sediment to the shelf during most of the glacial-eustatic cycle than they do at present. The timing of delta formation, sediment delivery and the character of sand bodies associated with these deltas varied across the shelf. These differences in delta evolution and associated sand body formation and character are mainly due to the different response time of individual fluvial systems to sea-level and climate change. No two deltas responded in the same way or at the same time to these changes, but there are patterns that can be used to understand eustatic and climatic influence on delta evolution.

AAPG Search and Discovery Article #90906©2001 AAPG Annual Convention, Denver, Colorado