Needham, D.T. (2004) Deformation in Moffat Shale detachment zones in the western part of the Scottish Southern Uplands. Geological Magazine, 141 (4). pp. 441-453. ISSN 0016-7568
A study of the décollement zones in the Moffat Shale Group in the Ordovician Northern Belt of the Southern Uplands of Scotland reveals a progressive sequence of deformation and increased channelization of fluid flow. The study concentrates on exposures of imbricated Moffat Shale on the western coast of the Rhins of Galloway.
Initial deformation occurred in partially lithified sediments and involved stratal disruption and shearing of the shales. Deformation then became more localized in narrower fault zones characterized by polyphase hydrothermal fluid flow/veining events. Deformation continued after vein formation, resulting in the development of low-temperature crystal plastic microstructures and further veining. Late-stage deformation is recorded as a pressure solution event possibly reflecting the cessation of slip on these faults as the slice became accreted. Most deformation can be ascribed to SE-directed thrusting and incorporation of the individual sheets into the Southern Uplands thrust stack. Later sinistral shear deformation, not observed in overlying turbidites, is also localized in these fault zones. The study reveals the likely structures formed at levels of an accretionary prism deforming under diagenetic to low-grade metamorphic conditions.
|Copyright, Publisher and Additional Information:||© Cambridge University Press|
|Keywords:||Southern Uplands, Scotland, faults, deformation, fluid flow|
|Institution:||The University of Leeds|
|Academic Units:||The University of Leeds > Faculty of Environment (Leeds) > School of Earth and Environment (Leeds) > Earth Sciences (Leeds)|
|Depositing User:||Repository Assistant|
|Date Deposited:||05 Jun 2006|
|Last Modified:||16 Sep 2016 17:13|
|Publisher:||Cambridge University Press|