Late Quaternary sedimentation

Abstract
The Gulf of Mexico basin (Fig. 1) is the largest semi-enclosed depositional basin in North America and has been the site of extensive hydrocarbon exploration and exploitation since the turn of the century. Since Late Jurassic times, the drainage basin of the Mississippi River system has been delivering sediments to the Gulf of Mexico (Worzel and Burke, 1978; Chapter 8, this volume). Mesozoic and Cenozoic deposits are estimated to have attained a total thickness in excess of 15 km (Martin and Bouma, 1978; Bouma and others, 1978a). Thus, the river system has been operative over relatively long periods of time, constantly feeding sediments to the receiving basin and building a thick Jurassic, Cretaceous, Tertiary, and Quaternary sequence of interfingering deltaic, nearshore coastal brackish water, and marine sediments, which have prograded the coastal plain shoreline seaward. Relatively little sediment yield has occurred during the Quaternary from the southern rim of the Gulf of Mexico basin. Through time, depocenters have shifted within the northern flank of the basin, forming a relatively thick sequence of Tertiary and Quaternary clastic sediments. The zone of maximum thickness trends roughly east-west near the present-day coastal plain of Louisiana and west toward Texas. Rapid subsidence associated primarily with sediment loading and salt and shale diapirism has been responsible for unusually thick, localized sedimentary accumulations and for the complex bathymetry on the continental slope (Fig. 1; Plate I, this volume). Throughout the Tertiary and Quaternary, minor and major transgressions and regressions have occurred, although the major depositional component