East Louisiana continental shelf sediments: a product of delta reworking

Journal of Coastal Research
By: , and 

Links

Abstract

Data from 77 vibracores were integrated with 6,700 line-km of high- resolution seismic reflection profiles collected off the eastern Louisiana coast in the region of the St. Bernard Delta, the first of the Holocene highstand deltas of the Mississippi River. Seismic fades and sediment facies were integrated in order to establish the stratigraphic details within this relict delta. Results provide a regional geologic framework from which comparisons can be made with other areas. Holocene deposits in the study area overlie a heavily dissected surface interpreted to represent a lowstand erosional surface. Resting on this surface is a thin unit of relatively clean, quartz sand interpreted to have been deposited during early transgression. This unit is overlain by sediments of the St. Bernard Delta, a seaward-prograding, coarsening-upward wedge of sands and muds that contain vertically-stacked units of deltaic succession. Two or more prograding units separated by an unconformity, delineated from regional seismic profiles, may represent laterally shifting subdelta lobes. Surficial sediments consist of a thin unit of sands and muds derived from and reflecting the individual subenvirons of the underlying delta. Holocene inner-shelf development off eastern Louisiana has been controlled by relative sea-level rise and sediment supply. Sediment supply and deposition are a product of delta progradation and delta-lobe switching. The modern shelf configuration and surficial sediment distribution patterns reflect reworking of underlying deltaic deposits. The lack of modern sediment input helps to maintain the imprint of this ancient delta on the modern shelf surface.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title East Louisiana continental shelf sediments: a product of delta reworking
Series title Journal of Coastal Research
Volume 11
Issue 4
Year Published 1995
Language English
Publisher Coastal Education and Research Foundation
Description 11 p.
First page 1026
Last page 1036
Country United States
State Louisiana
Other Geospatial St . Bernard Delta
Online Only (Y/N) N
Additional Online Files (Y/N) N
Google Analytic Metrics Metrics page