Analogue experiments on releasing and restraining bends and their application to the study of the Barents Shear Margin
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Published:2023-08-31
Issue:9
Volume:14
Page:961-983
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ISSN:1869-9529
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Container-title:Solid Earth
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language:en
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Short-container-title:Solid Earth
Author:
Gabrielsen Roy HelgeORCID, Giannenas Panagiotis AthanasiosORCID, Sokoutis Dimitrios, Willingshofer Ernst, Hassaan Muhammad, Faleide Jan Inge
Abstract
Abstract. The Barents Shear Margin separates the Svalbard and Barents Sea from the
North Atlantic. During the break-up of the North Atlantic the plate tectonic
configuration was characterized by sequential dextral shear, extension, and
eventually contraction and inversion. This generated a complex zone of
deformation that contains several structural families of overlapping and
reactivated structures. A series of crustal-scale analogue experiments, utilizing a scaled and
stratified sand–silicon polymer sequence, was used in the study of the
structural evolution of the shear margin. The most significant observations for interpreting the structural
configuration of the Barents Shear Margin are the following.
Prominent early-stage positive structural elements (e.g. folds, push-ups)
interacted with younger (e.g. inversion) structures and contributed to a
hybrid final structural pattern. Several structural features that were initiated during the early (dextral
shear) stage became overprinted and obliterated in the subsequent stages. All master faults, pull-apart basins, and extensional shear duplexes
initiated during the shear stage quickly became linked in the extension
stage, generating a connected basin system along the entire shear margin at
the stage of maximum extension. The fold pattern was generated during the terminal stage
(contraction–inversion became dominant in the basin areas) and was
characterized by fold axes striking parallel to the basin margins. These
folds, however, strongly affected the shallow intra-basin layers.
The experiments reproduced the geometry and positions of the major basins
and relations between structural elements (fault-and-fold systems) as
observed along and adjacent to the Barents Shear Margin. This supports the
present structural model for the shear margin.
Funder
Norges Forskningsråd
Publisher
Copernicus GmbH
Subject
Paleontology,Stratigraphy,Earth-Surface Processes,Geochemistry and Petrology,Geology,Geophysics,Soil Science
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