Skip to Main Content
Book Chapter

Late Quaternary Sea-Level Fluctuations and Depositional Sequences, Southwest Louisiana Continental Shelf

By
John R. Suter
John R. Suter
Louisiana Geological Survey, Coastal Geology Program, P.O. Box G, University Station, Baton Rouge, Louisiana 70893
Search for other works by this author on:
Henry L. Berryhill, JR.
Henry L. Berryhill, JR.
U.S. Geological Survey, P.O. Box 6732, Corpus Christi, Texas 78411
Search for other works by this author on:
Shea Penland
Shea Penland
Louisiana Geological Survey, Coastal Geology Program, P.O. Box G, University Station, Baton Rouge, Louisiana 70893
Search for other works by this author on:
Published:
January 01, 1987

Abstract:

Interpretations of over 20,000 line km of single-channel, high-resolution seismic-reflection profiles, coupled with nearshore vibracores and logs of industrial platform borings, provide the data base for determining the history and stratigraphy of late Quaternary sea-level fluctuations on the southwest Louisiana continental shelf. Regional unconformities, formed by subaerial exposure of the shelf during glacio-eustatic sea-level falls and modified by shoreface erosion during ensuing transgression, serve as markers to identify the boundaries of depositional sequences. Unconformities are recognizable on seismic profiles by high-amplitude reflectors as well as discordant relationships between reflectors.

Within the upper Quaternary section, six depositional sequences have been recognized. Five of these are related to glacio-eustatic fluctuations, involving sea-level fall close to, or beyond, the margin of the continental shelf. Three of these fluctuations culminated in the deposition of shelf-margin delta sequences. Extensive fluvial channeling characterizes the regressive phase of these sequences. Transgressive phases are marked by infilling of fluvial channels, floodplain aggradation, truncation, or deposition of sand sheets, depending upon sediment supply and rate of sea-level rise. Sequences 4 and 5 are correlated with the late Wisconsinan glacial stage and Holocene transgression. The upper portion of sequence 5 consists of an early Holocene Mississippi delta complex. Abandonment and transgression of this delta are responsible for the formation of sequence 6. Although these deposits cover a smaller area, this demonstrates that deltaic processes can produce sequences similar to those driven by glacially-controlled sea-level changes.

You do not currently have access to this article.

Figures & Tables

Contents

SEPM Special Publication

Sea-Level Fluctuation and Coastal Evolution

Dag Nummedal
Dag Nummedal
Department of Geology and Geophysics Louisiana State University, Baton Rouge, Louisiana
Search for other works by this author on:
Orrin H. Pilkey
Orrin H. Pilkey
Department of Geology Duke University, Durham, North Carolina
Search for other works by this author on:
James D. Howard
James D. Howard
Skidaway Institute of Oceanography Savannah, Georgia
Search for other works by this author on:
SEPM Society for Sedimentary Geology
Volume
41
ISBN electronic:
9781565760950
Publication date:
January 01, 1987

GeoRef

References

Related

Citing Books via

Close Modal
This Feature Is Available To Subscribers Only

Sign In or Create an Account

Close Modal
Close Modal