Three-dimensional GPR imaging of the Benmore anticline and step-over of the Ostler Fault, South Island, New Zealand
Because surface processes can frequently remove, mask or suppress the surface expression of faults, geophysical imaging is needed to provide information on the geometric expression of the fault in the subsurface, including dips, the presence or absence of splays and folds and the nature of the mater...
Published in: | Geophysical Journal International |
---|---|
Main Authors: | , , , , |
Format: | Text |
Language: | English |
Published: |
Oxford University Press
2010
|
Subjects: | |
Online Access: | http://gji.oxfordjournals.org/cgi/content/short/180/2/465 https://doi.org/10.1111/j.1365-246X.2009.04400.x |
id |
fthighwire:oai:open-archive.highwire.org:gji:180/2/465 |
---|---|
record_format |
openpolar |
spelling |
fthighwire:oai:open-archive.highwire.org:gji:180/2/465 2023-05-15T17:09:26+02:00 Three-dimensional GPR imaging of the Benmore anticline and step-over of the Ostler Fault, South Island, New Zealand Wallace, Shamus C. Nobes, David C. Davis, Kenneth J. Burbank, Douglas W. White, Antony 2010-02-01 00:00:00.0 text/html http://gji.oxfordjournals.org/cgi/content/short/180/2/465 https://doi.org/10.1111/j.1365-246X.2009.04400.x en eng Oxford University Press http://gji.oxfordjournals.org/cgi/content/short/180/2/465 http://dx.doi.org/10.1111/j.1365-246X.2009.04400.x Copyright (C) 2010, Oxford University Press Geodynamics and Tectonics TEXT 2010 fthighwire https://doi.org/10.1111/j.1365-246X.2009.04400.x 2013-05-28T01:06:46Z Because surface processes can frequently remove, mask or suppress the surface expression of faults, geophysical imaging is needed to provide information on the geometric expression of the fault in the subsurface, including dips, the presence or absence of splays and folds and the nature of the material in the fault plane. Subsurface data become especially important where a step-over occurs, however the mechanism of the step-over is not clear. The Ostler Fault is a major thrust fault in the Mackenzie Basin of the South Island of New Zealand. The geometry of the fault changes along its length, with a number of growing anticlines and step-overs forming the Ostler Fault Zone (OFZ). One of these anticlines occurs along the Benmore segment of the OFZ. A three-dimensional (3-D) ground penetrating radar (GPR) survey was carried out to supplement detailed surface topographic mapping and help characterize the nature of the OFZ at Benmore. To cover the 1 km length of the step-over, the 3-D survey was done with a coarse yet regular 50 m line spacing. The individual fault splays were continuous and could be traced from line to line. Not all splays had surface expression, whereas almost all surface features had corresponding subsurface expression. As the fault approaches the anticline and multiple splays become apparent, the main fault simply develops into one of a set of splays as the deformation becomes distributed across the wider zone. Eventually, one of the other splays becomes the primary fault strand, and the others are abandoned. Text Mackenzie Basin HighWire Press (Stanford University) New Zealand Geophysical Journal International 180 2 465 474 |
institution |
Open Polar |
collection |
HighWire Press (Stanford University) |
op_collection_id |
fthighwire |
language |
English |
topic |
Geodynamics and Tectonics |
spellingShingle |
Geodynamics and Tectonics Wallace, Shamus C. Nobes, David C. Davis, Kenneth J. Burbank, Douglas W. White, Antony Three-dimensional GPR imaging of the Benmore anticline and step-over of the Ostler Fault, South Island, New Zealand |
topic_facet |
Geodynamics and Tectonics |
description |
Because surface processes can frequently remove, mask or suppress the surface expression of faults, geophysical imaging is needed to provide information on the geometric expression of the fault in the subsurface, including dips, the presence or absence of splays and folds and the nature of the material in the fault plane. Subsurface data become especially important where a step-over occurs, however the mechanism of the step-over is not clear. The Ostler Fault is a major thrust fault in the Mackenzie Basin of the South Island of New Zealand. The geometry of the fault changes along its length, with a number of growing anticlines and step-overs forming the Ostler Fault Zone (OFZ). One of these anticlines occurs along the Benmore segment of the OFZ. A three-dimensional (3-D) ground penetrating radar (GPR) survey was carried out to supplement detailed surface topographic mapping and help characterize the nature of the OFZ at Benmore. To cover the 1 km length of the step-over, the 3-D survey was done with a coarse yet regular 50 m line spacing. The individual fault splays were continuous and could be traced from line to line. Not all splays had surface expression, whereas almost all surface features had corresponding subsurface expression. As the fault approaches the anticline and multiple splays become apparent, the main fault simply develops into one of a set of splays as the deformation becomes distributed across the wider zone. Eventually, one of the other splays becomes the primary fault strand, and the others are abandoned. |
format |
Text |
author |
Wallace, Shamus C. Nobes, David C. Davis, Kenneth J. Burbank, Douglas W. White, Antony |
author_facet |
Wallace, Shamus C. Nobes, David C. Davis, Kenneth J. Burbank, Douglas W. White, Antony |
author_sort |
Wallace, Shamus C. |
title |
Three-dimensional GPR imaging of the Benmore anticline and step-over of the Ostler Fault, South Island, New Zealand |
title_short |
Three-dimensional GPR imaging of the Benmore anticline and step-over of the Ostler Fault, South Island, New Zealand |
title_full |
Three-dimensional GPR imaging of the Benmore anticline and step-over of the Ostler Fault, South Island, New Zealand |
title_fullStr |
Three-dimensional GPR imaging of the Benmore anticline and step-over of the Ostler Fault, South Island, New Zealand |
title_full_unstemmed |
Three-dimensional GPR imaging of the Benmore anticline and step-over of the Ostler Fault, South Island, New Zealand |
title_sort |
three-dimensional gpr imaging of the benmore anticline and step-over of the ostler fault, south island, new zealand |
publisher |
Oxford University Press |
publishDate |
2010 |
url |
http://gji.oxfordjournals.org/cgi/content/short/180/2/465 https://doi.org/10.1111/j.1365-246X.2009.04400.x |
geographic |
New Zealand |
geographic_facet |
New Zealand |
genre |
Mackenzie Basin |
genre_facet |
Mackenzie Basin |
op_relation |
http://gji.oxfordjournals.org/cgi/content/short/180/2/465 http://dx.doi.org/10.1111/j.1365-246X.2009.04400.x |
op_rights |
Copyright (C) 2010, Oxford University Press |
op_doi |
https://doi.org/10.1111/j.1365-246X.2009.04400.x |
container_title |
Geophysical Journal International |
container_volume |
180 |
container_issue |
2 |
container_start_page |
465 |
op_container_end_page |
474 |
_version_ |
1766065530739884032 |