Mesozoic tectonic evolution of the South Orkney Microcontinent, Scotia arc, Antarctica
The South Orkney Islands are the exposed part of a continental fragment on the southern limb of the Scotia arc. The islands are to a large extent composed of metapelites and metagreywackes of probable Triassic sedimentary age. Deformation related to an accretionary wedge setting, with associated met...
Published in: | Geological Magazine |
---|---|
Main Authors: | , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Cambridge University Press (CUP)
1997
|
Subjects: | |
Online Access: | http://dx.doi.org/10.1017/s0016756897007036 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0016756897007036 |
id |
crcambridgeupr:10.1017/s0016756897007036 |
---|---|
record_format |
openpolar |
spelling |
crcambridgeupr:10.1017/s0016756897007036 2024-09-15T17:48:38+00:00 Mesozoic tectonic evolution of the South Orkney Microcontinent, Scotia arc, Antarctica TROUW, R. A. J. PASSCHIER, C. W. SIMÕES, L. S. A. ANDREIS, R. R. VALERIANO, C. M. 1997 http://dx.doi.org/10.1017/s0016756897007036 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0016756897007036 en eng Cambridge University Press (CUP) https://www.cambridge.org/core/terms Geological Magazine volume 134, issue 3, page 383-401 ISSN 0016-7568 1469-5081 journal-article 1997 crcambridgeupr https://doi.org/10.1017/s0016756897007036 2024-07-31T04:04:15Z The South Orkney Islands are the exposed part of a continental fragment on the southern limb of the Scotia arc. The islands are to a large extent composed of metapelites and metagreywackes of probable Triassic sedimentary age. Deformation related to an accretionary wedge setting, with associated metamorphism from anchizone to the greenschist facies, are of Jurassic age (176–200 Ma). On Powell Island, in the centre of the archipelago, five phases of deformation are recognized. The first three, associated with the main metamorphism, are tentatively correlated with early Jurassic subduction along the Pacific margin of Gondwana. D 4 is a phase of middle to late Jurassic crustal extension associated with uplift. This extension phase may be related to opening of the Rocas Verdes basin in southern Chile, associated with the breakup of Gondwanaland. Upper Jurassic conglomerates cover the metamorphic rocks unconformably. D 5 is a phase of brittle extensional faulting probably associated with Cenozoic opening of the Powell basin west of the archipelago, and with development of the Scotia arc. Article in Journal/Newspaper Antarc* Antarctica Powell Island South Orkney Islands Cambridge University Press Geological Magazine 134 3 383 401 |
institution |
Open Polar |
collection |
Cambridge University Press |
op_collection_id |
crcambridgeupr |
language |
English |
description |
The South Orkney Islands are the exposed part of a continental fragment on the southern limb of the Scotia arc. The islands are to a large extent composed of metapelites and metagreywackes of probable Triassic sedimentary age. Deformation related to an accretionary wedge setting, with associated metamorphism from anchizone to the greenschist facies, are of Jurassic age (176–200 Ma). On Powell Island, in the centre of the archipelago, five phases of deformation are recognized. The first three, associated with the main metamorphism, are tentatively correlated with early Jurassic subduction along the Pacific margin of Gondwana. D 4 is a phase of middle to late Jurassic crustal extension associated with uplift. This extension phase may be related to opening of the Rocas Verdes basin in southern Chile, associated with the breakup of Gondwanaland. Upper Jurassic conglomerates cover the metamorphic rocks unconformably. D 5 is a phase of brittle extensional faulting probably associated with Cenozoic opening of the Powell basin west of the archipelago, and with development of the Scotia arc. |
format |
Article in Journal/Newspaper |
author |
TROUW, R. A. J. PASSCHIER, C. W. SIMÕES, L. S. A. ANDREIS, R. R. VALERIANO, C. M. |
spellingShingle |
TROUW, R. A. J. PASSCHIER, C. W. SIMÕES, L. S. A. ANDREIS, R. R. VALERIANO, C. M. Mesozoic tectonic evolution of the South Orkney Microcontinent, Scotia arc, Antarctica |
author_facet |
TROUW, R. A. J. PASSCHIER, C. W. SIMÕES, L. S. A. ANDREIS, R. R. VALERIANO, C. M. |
author_sort |
TROUW, R. A. J. |
title |
Mesozoic tectonic evolution of the South Orkney Microcontinent, Scotia arc, Antarctica |
title_short |
Mesozoic tectonic evolution of the South Orkney Microcontinent, Scotia arc, Antarctica |
title_full |
Mesozoic tectonic evolution of the South Orkney Microcontinent, Scotia arc, Antarctica |
title_fullStr |
Mesozoic tectonic evolution of the South Orkney Microcontinent, Scotia arc, Antarctica |
title_full_unstemmed |
Mesozoic tectonic evolution of the South Orkney Microcontinent, Scotia arc, Antarctica |
title_sort |
mesozoic tectonic evolution of the south orkney microcontinent, scotia arc, antarctica |
publisher |
Cambridge University Press (CUP) |
publishDate |
1997 |
url |
http://dx.doi.org/10.1017/s0016756897007036 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0016756897007036 |
genre |
Antarc* Antarctica Powell Island South Orkney Islands |
genre_facet |
Antarc* Antarctica Powell Island South Orkney Islands |
op_source |
Geological Magazine volume 134, issue 3, page 383-401 ISSN 0016-7568 1469-5081 |
op_rights |
https://www.cambridge.org/core/terms |
op_doi |
https://doi.org/10.1017/s0016756897007036 |
container_title |
Geological Magazine |
container_volume |
134 |
container_issue |
3 |
container_start_page |
383 |
op_container_end_page |
401 |
_version_ |
1810290086941556736 |