The University of Southampton
University of Southampton Institutional Repository

Pull-aparts, shear fractures and pressure solution

Pull-aparts, shear fractures and pressure solution
Pull-aparts, shear fractures and pressure solution
Vein arrays are often composed of pull-aparts which are linked by shear fractures, good examples of which occur in the Lower Jurassic limestones of Somerset, southwestern England. Such pull-apart arrays have displacement-distance characteristics which are similar to fault zones, with maximum displacement (indicated by the largest pull-apart widths) near the centre of the array, and with displacement decreasing towards the tips. Pull-apart arrays usually die out into enéchelon or pinnate veins. Evidence for pressure solution along the shear fractures which connect pull-aparts include their dark and braided nature, their obliquity to the displacement direction, the high dihedral angles (often > 90°) between conjugate shear fractures, and the dissolution of earlier structures. A range of geometries occurs, with varying relative amounts of veins and pressure solution being related to varying amounts of transtension or transpression. There is a general trend for an increase in the angle between vein segments and the shear fractures as contraction increases. There is therefore a trend for increased pressure solution on the shear fractures in more contractional arrays. The concentration of insoluble material along shear fractures has important implications for the mechanics and sealing of faults.

0040-1951
1-13
Peacock, D.C.P.
54097ee9-4ba1-4691-836e-f72482e76160
Sanderson, D.J.
5653bc11-b905-4985-8c16-c655b2170ba9
Peacock, D.C.P.
54097ee9-4ba1-4691-836e-f72482e76160
Sanderson, D.J.
5653bc11-b905-4985-8c16-c655b2170ba9

Peacock, D.C.P. and Sanderson, D.J. (1995) Pull-aparts, shear fractures and pressure solution. Tectonophysics, 241 (1-2), 1-13. (doi:10.1016/0040-1951(94)00184-B).

Record type: Article

Abstract

Vein arrays are often composed of pull-aparts which are linked by shear fractures, good examples of which occur in the Lower Jurassic limestones of Somerset, southwestern England. Such pull-apart arrays have displacement-distance characteristics which are similar to fault zones, with maximum displacement (indicated by the largest pull-apart widths) near the centre of the array, and with displacement decreasing towards the tips. Pull-apart arrays usually die out into enéchelon or pinnate veins. Evidence for pressure solution along the shear fractures which connect pull-aparts include their dark and braided nature, their obliquity to the displacement direction, the high dihedral angles (often > 90°) between conjugate shear fractures, and the dissolution of earlier structures. A range of geometries occurs, with varying relative amounts of veins and pressure solution being related to varying amounts of transtension or transpression. There is a general trend for an increase in the angle between vein segments and the shear fractures as contraction increases. There is therefore a trend for increased pressure solution on the shear fractures in more contractional arrays. The concentration of insoluble material along shear fractures has important implications for the mechanics and sealing of faults.

This record has no associated files available for download.

More information

Published date: 15 January 1995

Identifiers

Local EPrints ID: 73712
URI: http://eprints.soton.ac.uk/id/eprint/73712
ISSN: 0040-1951
PURE UUID: 052dd240-5940-4068-92cb-60cf0a31718e
ORCID for D.J. Sanderson: ORCID iD orcid.org/0000-0002-2144-3527

Catalogue record

Date deposited: 11 Mar 2010
Last modified: 14 Mar 2024 02:53

Export record

Altmetrics

Contributors

Author: D.C.P. Peacock
Author: D.J. Sanderson ORCID iD

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×