Skip to Main Content
Book Chapter

Some consequences of mechanical stratification in basin-scale numerical models of passive-margin salt tectonics

By
Markus Albertz
Markus Albertz
Department of Oceanography, Dalhousie University, Halifax, NS, B3H 4J1, CanadaExxonMobil Upstream Research Company, PO Box 2189, Houston, Texas 77252-2189, USA
Search for other works by this author on:
Steven J. Ings
Steven J. Ings
Department of Oceanography, Dalhousie University, Halifax, NS, B3H 4J1, CanadaDepartment of Earth Sciences, Memorial University of Newfoundland, St John's, NL, A1B 3X5, Canada
Search for other works by this author on:
Published:
January 01, 2012

Abstract

Two-dimensional plane-strain numerical experiments illustrate the effects of variable evaporite viscosity and embedded frictional-plastic sediment layers on the style of salt flow and associated deformation of the sedimentary overburden. Evaporite viscosity exerts a first-order control on the salt flow rate and the style of overburden deformation. Nearly complete evacuation of low-viscosity salt occurs beneath expulsion basins, whereas significant salt is trapped when viscosity is high. Embedded frictional-plastic sediment layers with yield strength partition salt flow and develop transient contractional structures (folds, thrust faults and folded faults) in a seaward salt-squeeze flow regime. Multiple internal sediment layers reduce the seaward salt flow during sediment aggradation, leaving more salt behind to be remobilized during subsequent progradation. This produces more seaward extensive allochthonous salt sheets. If there is a density difference between the embedded layers and the surrounding salt, then the embedded layers fractionate during deformation and either float to the surface or sink to the bottom, creating a thick zone of pure halite. Such a process of ‘buoyancy fractionation’ may partially explain the apparent paradox of layered salt in autochthonous salt basins and pure halite in allochthonous salt sheets.

Supplementary material

Animated gif files of the model results are available at http://www.geolsoc.org.uk/SUP18500.

You do not currently have access to this article.

Figures & Tables

Contents

Geological Society, London, Special Publications

Salt Tectonics, Sediments and Prospectivity

G. I. Alsop
G. I. Alsop
University of Aberdeen, UK
Search for other works by this author on:
S. G. Archer
S. G. Archer
University of Aberdeen, UK
Search for other works by this author on:
A. J. Hartley
A. J. Hartley
University of Aberdeen, UK
Search for other works by this author on:
N. T. Grant
N. T. Grant
ConocoPhillips UK Ltd, Aberdeen, UK
Search for other works by this author on:
R. Hodgkinson
R. Hodgkinson
Bowleven plc, Edinburgh, UK
Search for other works by this author on:
Geological Society of London
Volume
363
ISBN electronic:
9781862396111
Publication date:
January 01, 2012

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