Skip to Main Content
Book Chapter

Contra-Regional Faulting: Salt Withdrawal Compensation, Offshore Louisiana, Gulf of Mexico

By
G.M. Byrd Larberg
G.M. Byrd Larberg
Shell Offshore Incorporated
Search for other works by this author on:
Published:
January 01, 1983

Abstract

Differential loading of Jurassic-age salt by prograding Tertiary clastic wedges in the Gulf Coast Province of the United States is responsible for regional down-to-the-basin growth faults across which significant expansion of synchronous time-rock units occurs. Section which expands into these faults corresponds to the loading phase responsible for basinward salt flow. Similar expansion is also manifest in the seismic expression of large, semi-regional faults in the eastern offshore of Louisiana which are down-to-the-north listric. However, these contra-regional faults must not be considered classic growth faults. They are instead explained as compensation features which form during lateral (strike) withdrawal of salt from salt ridges into adjacent diapirs.

The ancestral Mississippi River and sea level fluctuations associated with North American glaciation in the Late Cenozoic are together responsible for the periodic input of incredible sediment volumes to the Louisiana offshore. During such times, sedimentation rates far exceed the accommodation ability of developing growth fault systems, and rapid clastic progradation of the shelf occurs. Salt, displaced basinward by prior growth fault development is overridden by sediments. Linear, strike-oriented salt ridges result which are constrained by sediments in both shoreward and basinward directions. They form the feedstock for diapiric salt movement along their axis. Lateral withdrawal of salt from these ridges into diapirs is responsible for a loss of volume in the ridge which is compensated by the formation of contra-regional faults which flank the growing salt domes.

You do not currently have access to this article.

Figures & Tables

Contents

AAPG Studies in Geology

Seismic Expression of Structural Styles: A Picture and Work Atlas. Volume 1–The Layered Earth, Volume 2–Tectonics Of Extensional Provinces, & Volume 3–Tectonics Of Compressional Provinces

A. W. Bally
A. W. Bally
Search for other works by this author on:
American Association of Petroleum Geologists
Volume
15
ISBN electronic:
9781629810188
Publication date:
January 01, 1983

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