Large-scale coast-parallel displacements in the Cordillera: a granitic resolution to a paleomagnetic dilemma
Resolution of the ‘Paleomagnetic dilemma’, the discrepancy between large paleomagnetically determined dextral displacement of outboard portions of the northern Cordillera, and much smaller osets implied by mapping and stratigraphic correlations, is fundamental to understanding the tectonic evolution...
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ftciteseerx:oai:CiteSeerX.psu:10.1.1.562.5308 2023-05-15T16:00:23+02:00 Large-scale coast-parallel displacements in the Cordillera: a granitic resolution to a paleomagnetic dilemma Stephen T. Johnston The Pennsylvania State University CiteSeerX Archives 1998 application/pdf http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.562.5308 http://web.uvic.ca/~stj/Assets/PDFs/99 STJ JSG.pdf en eng http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.562.5308 http://web.uvic.ca/~stj/Assets/PDFs/99 STJ JSG.pdf Metadata may be used without restrictions as long as the oai identifier remains attached to it. http://web.uvic.ca/~stj/Assets/PDFs/99 STJ JSG.pdf text 1998 ftciteseerx 2016-01-08T12:06:42Z Resolution of the ‘Paleomagnetic dilemma’, the discrepancy between large paleomagnetically determined dextral displacement of outboard portions of the northern Cordillera, and much smaller osets implied by mapping and stratigraphic correlations, is fundamental to understanding the tectonic evolution of the Cordillera. This paper presents structural orientation data from the middle Cretaceous Dawson Range batholith of west central Yukon and its wallrocks, and suggests that some of the ‘missing’ displacement may be found in intrusions. The elongate northwest-trending batholith has a margin-parallel foliation, a sub-horizontal stretching lineation, and records syn-intrusive dextral shearing. In country rocks adjacent to the batholith, north-trending lineations are deflected clockwise into near parallelism with the batholith’s margins; lineations from wallrock screens within the batholith are all aligned parallel with the batholith’s long axis. The Big Creek strike-slip fault forms the north-margin of the batholith and accommodated a minimum of 20 km of dextral slip. These observations imply that the batholith invaded an active dextral shear zone, accommodated shearing while crystallizing, and focused post-crystallization fault development. The batholith is conservatively estimated to have accommodated 45 km of syn-intrusive shearing. Collectively, middle Cretaceous intrusions of the northern Cordillera may account for>400 km of previously unrecognized dextral displacement. # 1999 Text Dawson Yukon Unknown Dawson Range ENVELOPE(-138.337,-138.337,62.583,62.583) Yukon |
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English |
description |
Resolution of the ‘Paleomagnetic dilemma’, the discrepancy between large paleomagnetically determined dextral displacement of outboard portions of the northern Cordillera, and much smaller osets implied by mapping and stratigraphic correlations, is fundamental to understanding the tectonic evolution of the Cordillera. This paper presents structural orientation data from the middle Cretaceous Dawson Range batholith of west central Yukon and its wallrocks, and suggests that some of the ‘missing’ displacement may be found in intrusions. The elongate northwest-trending batholith has a margin-parallel foliation, a sub-horizontal stretching lineation, and records syn-intrusive dextral shearing. In country rocks adjacent to the batholith, north-trending lineations are deflected clockwise into near parallelism with the batholith’s margins; lineations from wallrock screens within the batholith are all aligned parallel with the batholith’s long axis. The Big Creek strike-slip fault forms the north-margin of the batholith and accommodated a minimum of 20 km of dextral slip. These observations imply that the batholith invaded an active dextral shear zone, accommodated shearing while crystallizing, and focused post-crystallization fault development. The batholith is conservatively estimated to have accommodated 45 km of syn-intrusive shearing. Collectively, middle Cretaceous intrusions of the northern Cordillera may account for>400 km of previously unrecognized dextral displacement. # 1999 |
author2 |
The Pennsylvania State University CiteSeerX Archives |
format |
Text |
author |
Stephen T. Johnston |
spellingShingle |
Stephen T. Johnston Large-scale coast-parallel displacements in the Cordillera: a granitic resolution to a paleomagnetic dilemma |
author_facet |
Stephen T. Johnston |
author_sort |
Stephen T. Johnston |
title |
Large-scale coast-parallel displacements in the Cordillera: a granitic resolution to a paleomagnetic dilemma |
title_short |
Large-scale coast-parallel displacements in the Cordillera: a granitic resolution to a paleomagnetic dilemma |
title_full |
Large-scale coast-parallel displacements in the Cordillera: a granitic resolution to a paleomagnetic dilemma |
title_fullStr |
Large-scale coast-parallel displacements in the Cordillera: a granitic resolution to a paleomagnetic dilemma |
title_full_unstemmed |
Large-scale coast-parallel displacements in the Cordillera: a granitic resolution to a paleomagnetic dilemma |
title_sort |
large-scale coast-parallel displacements in the cordillera: a granitic resolution to a paleomagnetic dilemma |
publishDate |
1998 |
url |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.562.5308 http://web.uvic.ca/~stj/Assets/PDFs/99 STJ JSG.pdf |
long_lat |
ENVELOPE(-138.337,-138.337,62.583,62.583) |
geographic |
Dawson Range Yukon |
geographic_facet |
Dawson Range Yukon |
genre |
Dawson Yukon |
genre_facet |
Dawson Yukon |
op_source |
http://web.uvic.ca/~stj/Assets/PDFs/99 STJ JSG.pdf |
op_relation |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.562.5308 http://web.uvic.ca/~stj/Assets/PDFs/99 STJ JSG.pdf |
op_rights |
Metadata may be used without restrictions as long as the oai identifier remains attached to it. |
_version_ |
1766396371393314816 |