The Hyde-Macraes shear zone in Otago: A result of continental extension or shortening? A kinematic analysis of the Footwall Fault
Mineralised shear zones in Otago are often truncated by regional low-angle faults, which juxtapose schist of different metamorphic grade. The Footwall Fault and the Hyde-Macraes Shear Zone are one example for this kind of tectonic setting, and are the subject to this study. Although, the mechanisms...
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University of Canterbury. Geological Sciences
2008
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ndltd-canterbury.ac.nz-oai-ir.canterbury.ac.nz-10092-14222015-03-30T15:30:02ZThe Hyde-Macraes shear zone in Otago: A result of continental extension or shortening? A kinematic analysis of the Footwall FaultButz, Christoph FlorianHyde-Macraes Shear ZoneFootwall FaultOtago SchistMineralised shear zones in Otago are often truncated by regional low-angle faults, which juxtapose schist of different metamorphic grade. The Footwall Fault and the Hyde-Macraes Shear Zone are one example for this kind of tectonic setting, and are the subject to this study. Although, the mechanisms for the development of the mineralised thrust-origin shear zones are well studied, the relationship to the truncating faults is still poorly understood. Currently, the truncating low-angle faults are assumed to be related to crustal extension, starting in the early Cretaceous after the schist passed the ductile-brittle transition. This study presents new kinematic data for the Footwall Fault, suggesting development of normal sense movement under ductile conditions due to an abundant shear band cleavage in the footwall, which dynamically recrystallises quartz grains. However, brittle high-angle normal faults truncating these shear bands indicate either reactivation of normal sense movement after passing the ductile-brittle transition or continuous normal sense movement during the transition. Furthermore, this study presents a model, which suggests a regional scale rolling hinge development, consisting of an array of individual low-angle normal faults along the boundary of the textural zone change from TZ IV to TZIII, and strike-parallel high-angle faults at the NE margin of the Otago schist.University of Canterbury. Geological Sciences2008-09-08T00:01:23Z2008-09-08T00:01:23Z2007Electronic thesis or dissertationTexthttp://hdl.handle.net/10092/1422enNZCUCopyright Christoph Florian Butzhttp://library.canterbury.ac.nz/thesis/etheses_copyright.shtml |
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en |
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Hyde-Macraes Shear Zone Footwall Fault Otago Schist |
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Hyde-Macraes Shear Zone Footwall Fault Otago Schist Butz, Christoph Florian The Hyde-Macraes shear zone in Otago: A result of continental extension or shortening? A kinematic analysis of the Footwall Fault |
description |
Mineralised shear zones in Otago are often truncated by regional low-angle faults, which juxtapose schist of different metamorphic grade. The Footwall Fault and the Hyde-Macraes Shear Zone are one example for this kind of tectonic setting, and are the subject to this study. Although, the mechanisms for the development of the mineralised thrust-origin shear zones are well studied, the relationship to the truncating faults is still poorly understood. Currently, the truncating low-angle faults are assumed to be related to crustal extension, starting in the early Cretaceous after the schist passed the ductile-brittle transition. This study presents new kinematic data for the Footwall Fault, suggesting development of normal sense movement under ductile conditions due to an abundant shear band cleavage in the footwall, which dynamically recrystallises quartz grains. However, brittle high-angle normal faults truncating these shear bands indicate either reactivation of normal sense movement after passing the ductile-brittle transition or continuous normal sense movement during the transition. Furthermore, this study presents a model, which suggests a regional scale rolling hinge development, consisting of an array of individual low-angle normal faults along the boundary of the textural zone change from TZ IV to TZIII, and strike-parallel high-angle faults at the NE margin of the Otago schist. |
author |
Butz, Christoph Florian |
author_facet |
Butz, Christoph Florian |
author_sort |
Butz, Christoph Florian |
title |
The Hyde-Macraes shear zone in Otago: A result of continental extension or shortening? A kinematic analysis of the Footwall Fault |
title_short |
The Hyde-Macraes shear zone in Otago: A result of continental extension or shortening? A kinematic analysis of the Footwall Fault |
title_full |
The Hyde-Macraes shear zone in Otago: A result of continental extension or shortening? A kinematic analysis of the Footwall Fault |
title_fullStr |
The Hyde-Macraes shear zone in Otago: A result of continental extension or shortening? A kinematic analysis of the Footwall Fault |
title_full_unstemmed |
The Hyde-Macraes shear zone in Otago: A result of continental extension or shortening? A kinematic analysis of the Footwall Fault |
title_sort |
hyde-macraes shear zone in otago: a result of continental extension or shortening? a kinematic analysis of the footwall fault |
publisher |
University of Canterbury. Geological Sciences |
publishDate |
2008 |
url |
http://hdl.handle.net/10092/1422 |
work_keys_str_mv |
AT butzchristophflorian thehydemacraesshearzoneinotagoaresultofcontinentalextensionorshorteningakinematicanalysisofthefootwallfault AT butzchristophflorian hydemacraesshearzoneinotagoaresultofcontinentalextensionorshorteningakinematicanalysisofthefootwallfault |
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