Structural and temporal evolution of a reactivated brittle-ductile fault - Part II: Timing of fault initiation and reactivation by K-Ar dating of synkinematic illite/muscovite
Present-day exposures of ancient faults represent only the end result of the faults' often protracted and heterogeneous histories. Here we apply K–Ar dating of synkinematic illite/muscovite to constrain the timing of the complete temporal evolution of a complex, multiply-reactivated brittle–duc...
Published in: | Earth and Planetary Science Letters |
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Online Access: | https://hdl.handle.net/20.500.11937/41682 https://doi.org/10.1016/j.epsl.2014.09.031 |
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ftcurtin:oai:espace.curtin.edu.au:20.500.11937/41682 2023-06-11T04:15:21+02:00 Structural and temporal evolution of a reactivated brittle-ductile fault - Part II: Timing of fault initiation and reactivation by K-Ar dating of synkinematic illite/muscovite Torgersen, E. Viola, G. Zwingmann, Horst Harris, C. 2014 restricted https://hdl.handle.net/20.500.11937/41682 https://doi.org/10.1016/j.epsl.2014.09.031 unknown Elsevier BV http://hdl.handle.net/20.500.11937/41682 doi:10.1016/j.epsl.2014.09.031 Journal Article 2014 ftcurtin https://doi.org/20.500.11937/4168210.1016/j.epsl.2014.09.031 2023-05-30T19:42:06Z Present-day exposures of ancient faults represent only the end result of the faults' often protracted and heterogeneous histories. Here we apply K–Ar dating of synkinematic illite/muscovite to constrain the timing of the complete temporal evolution of a complex, multiply-reactivated brittle–ductile fault, the Kvenklubben Fault in northern Norway. All obtained ages vary as a function of grain size. Geologically significant events are identified principally on the basis of detailed structural analysis presented in a companion paper (Torgersen and Viola, 2014). Faulting initiated at View the MathML source531±11Ma, but most strain was accommodated during Caledonian compression at View the MathML source445±9Ma. The fault was reactivated extensionally at View the MathML source121±5Ma. C and O isotopic composition of carbonates and silicates in the fault rocks demonstrates that mineral authigenesis was linked to wall–rock disintegration through dolomite decarbonation and metabasalt carbonation. We suggest that the commonly observed case of age decreasing with grain size in K–Ar and 40Ar/39Ar dating of brittle fault rocks can be interpreted as a consequence of mixing between two end-member illite/muscovite generations: an authigenic and a protolithic, in which the finest authigenic grains constrain the timing of the last faulting increment. Integrating detailed structural analysis with age dating is the key towards a better understanding of fault architecture development and the temporal evolution of strain localization and deformation mechanisms. Article in Journal/Newspaper Northern Norway Curtin University: espace Kvenklubben ENVELOPE(23.637,23.637,70.405,70.405) Norway Torgersen ENVELOPE(-64.074,-64.074,-64.773,-64.773) Earth and Planetary Science Letters 407 221 233 |
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Open Polar |
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Curtin University: espace |
op_collection_id |
ftcurtin |
language |
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description |
Present-day exposures of ancient faults represent only the end result of the faults' often protracted and heterogeneous histories. Here we apply K–Ar dating of synkinematic illite/muscovite to constrain the timing of the complete temporal evolution of a complex, multiply-reactivated brittle–ductile fault, the Kvenklubben Fault in northern Norway. All obtained ages vary as a function of grain size. Geologically significant events are identified principally on the basis of detailed structural analysis presented in a companion paper (Torgersen and Viola, 2014). Faulting initiated at View the MathML source531±11Ma, but most strain was accommodated during Caledonian compression at View the MathML source445±9Ma. The fault was reactivated extensionally at View the MathML source121±5Ma. C and O isotopic composition of carbonates and silicates in the fault rocks demonstrates that mineral authigenesis was linked to wall–rock disintegration through dolomite decarbonation and metabasalt carbonation. We suggest that the commonly observed case of age decreasing with grain size in K–Ar and 40Ar/39Ar dating of brittle fault rocks can be interpreted as a consequence of mixing between two end-member illite/muscovite generations: an authigenic and a protolithic, in which the finest authigenic grains constrain the timing of the last faulting increment. Integrating detailed structural analysis with age dating is the key towards a better understanding of fault architecture development and the temporal evolution of strain localization and deformation mechanisms. |
format |
Article in Journal/Newspaper |
author |
Torgersen, E. Viola, G. Zwingmann, Horst Harris, C. |
spellingShingle |
Torgersen, E. Viola, G. Zwingmann, Horst Harris, C. Structural and temporal evolution of a reactivated brittle-ductile fault - Part II: Timing of fault initiation and reactivation by K-Ar dating of synkinematic illite/muscovite |
author_facet |
Torgersen, E. Viola, G. Zwingmann, Horst Harris, C. |
author_sort |
Torgersen, E. |
title |
Structural and temporal evolution of a reactivated brittle-ductile fault - Part II: Timing of fault initiation and reactivation by K-Ar dating of synkinematic illite/muscovite |
title_short |
Structural and temporal evolution of a reactivated brittle-ductile fault - Part II: Timing of fault initiation and reactivation by K-Ar dating of synkinematic illite/muscovite |
title_full |
Structural and temporal evolution of a reactivated brittle-ductile fault - Part II: Timing of fault initiation and reactivation by K-Ar dating of synkinematic illite/muscovite |
title_fullStr |
Structural and temporal evolution of a reactivated brittle-ductile fault - Part II: Timing of fault initiation and reactivation by K-Ar dating of synkinematic illite/muscovite |
title_full_unstemmed |
Structural and temporal evolution of a reactivated brittle-ductile fault - Part II: Timing of fault initiation and reactivation by K-Ar dating of synkinematic illite/muscovite |
title_sort |
structural and temporal evolution of a reactivated brittle-ductile fault - part ii: timing of fault initiation and reactivation by k-ar dating of synkinematic illite/muscovite |
publisher |
Elsevier BV |
publishDate |
2014 |
url |
https://hdl.handle.net/20.500.11937/41682 https://doi.org/10.1016/j.epsl.2014.09.031 |
long_lat |
ENVELOPE(23.637,23.637,70.405,70.405) ENVELOPE(-64.074,-64.074,-64.773,-64.773) |
geographic |
Kvenklubben Norway Torgersen |
geographic_facet |
Kvenklubben Norway Torgersen |
genre |
Northern Norway |
genre_facet |
Northern Norway |
op_relation |
http://hdl.handle.net/20.500.11937/41682 doi:10.1016/j.epsl.2014.09.031 |
op_doi |
https://doi.org/20.500.11937/4168210.1016/j.epsl.2014.09.031 |
container_title |
Earth and Planetary Science Letters |
container_volume |
407 |
container_start_page |
221 |
op_container_end_page |
233 |
_version_ |
1768372099831824384 |