Spatial variability of the Purbeck–Wight Fault Zone—a long-lived tectonic element in the southern UK

Westhead, R.K.; McCarthy, D.J.; Collier, J.S.; Sanderson, D.J.. 2018 Spatial variability of the Purbeck–Wight Fault Zone—a long-lived tectonic element in the southern UK. Proceedings of the Geologists' Association, 129 (3). 436-451. https://doi.org/10.1016/j.pgeola.2017.08.005

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Official URL: https://doi.org/10.1016/j.pgeola.2017.08.005

Abstract/Summary

New seamless onshore to offshore bedrock (1:10 k scale) mapping for the Lyme Bay area is used to resolve the westward termination of the Purbeck–Wight Fault Zone (PWFZ) structure, comprising one of the most prominent, long-lived (Variscan–Cimmerian–Alpine) structural lineaments in the southern UK. The study area lies south of the Variscan Frontal Thrust and overlays the basement Variscide Rhenohercynian Zone, in a region of dominant E-W tectonic fabric and a secondary conjugate NW-SE/NE-SW fabric. The PWFZ comprises one of the E-W major structures, with a typical history including Permian to early Cretaceous growth movement (relating to basement Variscan Thrust reactivation) followed by significant Alpine (Helvetic) inversion. Previous interpretations of the PWFZ have been limited by the low resolution (1:250 k scale) of the available offshore BGS mapping, and our study fills this gap. We describe a significant change in structural style of the fault zone from east to west. In the Weymouth Bay area, previous studies demonstrate the development of focussed strain associated with the PWFZ, accompanied by distributed strain, N-S fault development, and potential basement uplift in its hangingwall. In the Lyme Bay area to the west, faulting is dominantly E-W, with N-S faulting absent. Comparison of the newly mapped faulting networks to gravity data suggests a spatial relationship between this faulting variation and basement variability and uplift.

Item Type:	Publication - Article
Digital Object Identifier (DOI):	https://doi.org/10.1016/j.pgeola.2017.08.005
ISSN:	00167878
Date made live:	14 Nov 2017 09:34 +0 (UTC)
URI:	https://nora.nerc.ac.uk/id/eprint/518338

Item Type:

Publication - Article

Digital Object Identifier (DOI):

https://doi.org/10.1016/j.pgeola.2017.08.005

ISSN:

00167878

Date made live:

14 Nov 2017 09:34 +0 (UTC)

URI:

https://nora.nerc.ac.uk/id/eprint/518338