Structural Evolution of Salt-Influenced Fold-and-Thrust belts: A Synthesis and New Insights From Basins Containing Isolated Salt Diapirs

This is a Preprint and has not been peer reviewed.

Downloads

Download Preprint

Supplementary Files
Authors

Oliver B Duffy, Tim P Dooley, Michael R Hudec, Martin P.A. Jackson, Naiara Fernandez , Christopher Aiden-Lee Jackson , Juan I. Soto 

Abstract

Lateral shortening is expressed in unique ways in salt basins, especially if pre-shortening diapirs are present. We present an overview and new 3-D conceptual models capturing the evolution of shortening structures formed in salt provinces dominated by precursor isolated diapirs (termed isolated-diapir provinces). In such provinces, isolated diapirs form only a minor volumetric component of a sedimentary basin, however, due to the relative weakness of rock salt and their ability to localize strain, during shortening they have a disproportionately large influence on structural development.
We find three key mechanical principles govern the processes and structural styles developed during shortening of isolated-diapir provinces. First, salt diapirs shorten before surrounding sedimentary rocks due to their relative weakness, and so form salients in the thrust front during early shortening. Second, diapirs tend to nucleate folds and faults, which radiate out from the diapirs. Third, as diapir walls converge, the roof must shorten. Extrusive salt sheets are expelled through thin roofs, but thicker roofs resist piercement and so tend to undergo complex folding and faulting.
As a result of these principles, the first-order controls on the structural styles expressed across a shortened isolated-diapir province are the pre-shortening configuration of diapirs, the connectivity of the diapirs prior to shortening, total strain magnitude, and diapir roof thickness. Second-order controls include the initial cross-sectional and map-view geometry of diapirs, diapir size, and diapir orientation with respect to the shortening direction.

DOI

https://doi.org/10.31223/osf.io/nd7et

Subjects

Earth Sciences, Physical Sciences and Mathematics, Tectonics and Structure

Keywords

salt tectonics, shortening, Gulf of Mexico, diapirs, Zagros, fold-and-thrust belts, physical modelling, welds

Dates

Published: 2018-04-30 18:20

Older Versions
License

CC BY Attribution 4.0 International

Add a Comment

You must log in to post a comment.


Comments

There are no comments or no comments have been made public for this article.