Deformation of the Isua block, West Greenland: a remnant of the earliest stable continental crust
The Isua block of West Greenland is composed of a belt of supracrustal rocks and surrounding granitic gneisses, both of which yield dates of approximately 3750 m.y. This age is equivalent to that of the Amitsoq gneisses of the nearby Godthaabsfjord area. From the lilhological variation and structura...
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Language: | English |
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Canadian Science Publishing
1976
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Online Access: | http://dx.doi.org/10.1139/e76-084 http://www.nrcresearchpress.com/doi/pdf/10.1139/e76-084 |
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crcansciencepubl:10.1139/e76-084 2024-04-07T07:52:49+00:00 Deformation of the Isua block, West Greenland: a remnant of the earliest stable continental crust James, Patrick R. 1976 http://dx.doi.org/10.1139/e76-084 http://www.nrcresearchpress.com/doi/pdf/10.1139/e76-084 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Earth Sciences volume 13, issue 6, page 816-823 ISSN 0008-4077 1480-3313 General Earth and Planetary Sciences journal-article 1976 crcansciencepubl https://doi.org/10.1139/e76-084 2024-03-08T00:37:30Z The Isua block of West Greenland is composed of a belt of supracrustal rocks and surrounding granitic gneisses, both of which yield dates of approximately 3750 m.y. This age is equivalent to that of the Amitsoq gneisses of the nearby Godthaabsfjord area. From the lilhological variation and structural style, two major deformalional events are recognised in both the supracrustals and the gneisses: D 1 , a phase of fabric formation caused by a vertical simple shear mainly affecting rocks of the supracrustal belt; and D 2 . a phase of major and minor folding of the earlier structures probably caused by an ENE–WSW ductile dextral simple shear movement. Measurements of the amount of strain from a distinctive conglomeratic unit yield strain paths for the two deformations and a value of vertical displacement of approximately 7 km for D 1 . Two dyke sets invade the supracrustals and gneisses, a tangential set during D 2 and a radial set after D 2 . Article in Journal/Newspaper Greenland Canadian Science Publishing Greenland Canadian Journal of Earth Sciences 13 6 816 823 |
institution |
Open Polar |
collection |
Canadian Science Publishing |
op_collection_id |
crcansciencepubl |
language |
English |
topic |
General Earth and Planetary Sciences |
spellingShingle |
General Earth and Planetary Sciences James, Patrick R. Deformation of the Isua block, West Greenland: a remnant of the earliest stable continental crust |
topic_facet |
General Earth and Planetary Sciences |
description |
The Isua block of West Greenland is composed of a belt of supracrustal rocks and surrounding granitic gneisses, both of which yield dates of approximately 3750 m.y. This age is equivalent to that of the Amitsoq gneisses of the nearby Godthaabsfjord area. From the lilhological variation and structural style, two major deformalional events are recognised in both the supracrustals and the gneisses: D 1 , a phase of fabric formation caused by a vertical simple shear mainly affecting rocks of the supracrustal belt; and D 2 . a phase of major and minor folding of the earlier structures probably caused by an ENE–WSW ductile dextral simple shear movement. Measurements of the amount of strain from a distinctive conglomeratic unit yield strain paths for the two deformations and a value of vertical displacement of approximately 7 km for D 1 . Two dyke sets invade the supracrustals and gneisses, a tangential set during D 2 and a radial set after D 2 . |
format |
Article in Journal/Newspaper |
author |
James, Patrick R. |
author_facet |
James, Patrick R. |
author_sort |
James, Patrick R. |
title |
Deformation of the Isua block, West Greenland: a remnant of the earliest stable continental crust |
title_short |
Deformation of the Isua block, West Greenland: a remnant of the earliest stable continental crust |
title_full |
Deformation of the Isua block, West Greenland: a remnant of the earliest stable continental crust |
title_fullStr |
Deformation of the Isua block, West Greenland: a remnant of the earliest stable continental crust |
title_full_unstemmed |
Deformation of the Isua block, West Greenland: a remnant of the earliest stable continental crust |
title_sort |
deformation of the isua block, west greenland: a remnant of the earliest stable continental crust |
publisher |
Canadian Science Publishing |
publishDate |
1976 |
url |
http://dx.doi.org/10.1139/e76-084 http://www.nrcresearchpress.com/doi/pdf/10.1139/e76-084 |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Greenland |
genre_facet |
Greenland |
op_source |
Canadian Journal of Earth Sciences volume 13, issue 6, page 816-823 ISSN 0008-4077 1480-3313 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/e76-084 |
container_title |
Canadian Journal of Earth Sciences |
container_volume |
13 |
container_issue |
6 |
container_start_page |
816 |
op_container_end_page |
823 |
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1795668304305586176 |