The structural evolution of the Rauer Group, East Antarctica: mafic dykes as passive markers in a composite Proterozoic terrain
Archaean gneisses in the Rauer Group of islands, East Antarctica, record a prolonged history of high-grade deformational episodes, many of which predate that identified in mid-Proterozoic gneisses. Eleven generations of mafic dykes, belonging to discrete chemical suites, have been used as relative t...
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Language: | English |
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Cambridge University Press (CUP)
1994
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Online Access: | http://dx.doi.org/10.1017/s0954102094000581 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0954102094000581 |
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crcambridgeupr:10.1017/s0954102094000581 2024-06-23T07:46:15+00:00 The structural evolution of the Rauer Group, East Antarctica: mafic dykes as passive markers in a composite Proterozoic terrain Sims, John P. Dirks, Paul H. G. M. Carson, Chris J. Wilson, Chris J. L. 1994 http://dx.doi.org/10.1017/s0954102094000581 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0954102094000581 en eng Cambridge University Press (CUP) https://www.cambridge.org/core/terms Antarctic Science volume 6, issue 3, page 379-394 ISSN 0954-1020 1365-2079 journal-article 1994 crcambridgeupr https://doi.org/10.1017/s0954102094000581 2024-06-12T04:04:31Z Archaean gneisses in the Rauer Group of islands, East Antarctica, record a prolonged history of high-grade deformational episodes, many of which predate that identified in mid-Proterozoic gneisses. Eleven generations of mafic dykes, belonging to discrete chemical suites, have been used as relative time markers to constrain this deformational history. Based on the timing of intrusion with respect to structures, dykes in the Rauer Group have been correlated with largely undeformed and dated dyke suites in the adjacent Vestfold Hills. This has allowed absolute ages to be inferred for the early- to mid-Proterozoic mafic dyke suites in the Rauer Group, and a correlation of the interspersed structural events. Most structures in the Rauer Group, however, developed in response to high-grade progressive deformation at approximately 1000 Ma. During this deformational episode, strains were repeatedly partitioned into sub-vertical, noncoaxial, high-strain zones recording NW-directed sinistral transpression, that separated zones of lower strain dominated by coaxial folding with axes parallel to the shear direction. Three additional mafic dyke suites intruded during this deformation which was followed by three stages of brittle-ductile deformation and a final suite of lamprophyre dykes. Due to the numerous intrusive time markers, the Rauer Group serves as an excellent illustration of how complicated gneiss terrains may be. Article in Journal/Newspaper Antarc* Antarctic Science Antarctica East Antarctica Cambridge University Press East Antarctica Rauer Group ENVELOPE(77.833,77.833,-68.850,-68.850) Vestfold Vestfold Hills Antarctic Science 6 3 379 394 |
institution |
Open Polar |
collection |
Cambridge University Press |
op_collection_id |
crcambridgeupr |
language |
English |
description |
Archaean gneisses in the Rauer Group of islands, East Antarctica, record a prolonged history of high-grade deformational episodes, many of which predate that identified in mid-Proterozoic gneisses. Eleven generations of mafic dykes, belonging to discrete chemical suites, have been used as relative time markers to constrain this deformational history. Based on the timing of intrusion with respect to structures, dykes in the Rauer Group have been correlated with largely undeformed and dated dyke suites in the adjacent Vestfold Hills. This has allowed absolute ages to be inferred for the early- to mid-Proterozoic mafic dyke suites in the Rauer Group, and a correlation of the interspersed structural events. Most structures in the Rauer Group, however, developed in response to high-grade progressive deformation at approximately 1000 Ma. During this deformational episode, strains were repeatedly partitioned into sub-vertical, noncoaxial, high-strain zones recording NW-directed sinistral transpression, that separated zones of lower strain dominated by coaxial folding with axes parallel to the shear direction. Three additional mafic dyke suites intruded during this deformation which was followed by three stages of brittle-ductile deformation and a final suite of lamprophyre dykes. Due to the numerous intrusive time markers, the Rauer Group serves as an excellent illustration of how complicated gneiss terrains may be. |
format |
Article in Journal/Newspaper |
author |
Sims, John P. Dirks, Paul H. G. M. Carson, Chris J. Wilson, Chris J. L. |
spellingShingle |
Sims, John P. Dirks, Paul H. G. M. Carson, Chris J. Wilson, Chris J. L. The structural evolution of the Rauer Group, East Antarctica: mafic dykes as passive markers in a composite Proterozoic terrain |
author_facet |
Sims, John P. Dirks, Paul H. G. M. Carson, Chris J. Wilson, Chris J. L. |
author_sort |
Sims, John P. |
title |
The structural evolution of the Rauer Group, East Antarctica: mafic dykes as passive markers in a composite Proterozoic terrain |
title_short |
The structural evolution of the Rauer Group, East Antarctica: mafic dykes as passive markers in a composite Proterozoic terrain |
title_full |
The structural evolution of the Rauer Group, East Antarctica: mafic dykes as passive markers in a composite Proterozoic terrain |
title_fullStr |
The structural evolution of the Rauer Group, East Antarctica: mafic dykes as passive markers in a composite Proterozoic terrain |
title_full_unstemmed |
The structural evolution of the Rauer Group, East Antarctica: mafic dykes as passive markers in a composite Proterozoic terrain |
title_sort |
structural evolution of the rauer group, east antarctica: mafic dykes as passive markers in a composite proterozoic terrain |
publisher |
Cambridge University Press (CUP) |
publishDate |
1994 |
url |
http://dx.doi.org/10.1017/s0954102094000581 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0954102094000581 |
long_lat |
ENVELOPE(77.833,77.833,-68.850,-68.850) |
geographic |
East Antarctica Rauer Group Vestfold Vestfold Hills |
geographic_facet |
East Antarctica Rauer Group Vestfold Vestfold Hills |
genre |
Antarc* Antarctic Science Antarctica East Antarctica |
genre_facet |
Antarc* Antarctic Science Antarctica East Antarctica |
op_source |
Antarctic Science volume 6, issue 3, page 379-394 ISSN 0954-1020 1365-2079 |
op_rights |
https://www.cambridge.org/core/terms |
op_doi |
https://doi.org/10.1017/s0954102094000581 |
container_title |
Antarctic Science |
container_volume |
6 |
container_issue |
3 |
container_start_page |
379 |
op_container_end_page |
394 |
_version_ |
1802644856703549440 |