Geology of Gjelsvikfjella and western Mühlig-Hofmannfjella, Dronning Maud Land, east Antarctica
As a part of the Norwegian Antarctic Research Expedition 1984/85, geological mapping was performed in Gjelsvikfjella and western Mühlig-Hofmannfjella, Dronning Maud Land. The northern part of Gjelsvikfjella is dominated by the Jutulsessen metasupracrustals which have been intruded by a major gabbroi...
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Norwegian Polar Institute
1990
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ftjpolarres:oai:journals.openacademia.net:article/2380 2023-05-15T14:01:21+02:00 Geology of Gjelsvikfjella and western Mühlig-Hofmannfjella, Dronning Maud Land, east Antarctica Ohta, Y. Tørudbakken, B. O. Shiraishi, K. 1990-01-12 application/pdf https://polarresearch.net/index.php/polar/article/view/2380 https://doi.org/10.3402/polar.v8i2.6808 eng eng Norwegian Polar Institute https://polarresearch.net/index.php/polar/article/view/2380/5630 https://polarresearch.net/index.php/polar/article/view/2380 doi:10.3402/polar.v8i2.6808 Copyright (c) 2018 Polar Research Polar Research; Vol. 8 No. 2 (1990); 99-126 1751-8369 info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion 1990 ftjpolarres https://doi.org/10.3402/polar.v8i2.6808 2021-11-11T19:12:32Z As a part of the Norwegian Antarctic Research Expedition 1984/85, geological mapping was performed in Gjelsvikfjella and western Mühlig-Hofmannfjella, Dronning Maud Land. The northern part of Gjelsvikfjella is dominated by the Jutulsessen metasupracrustals which have been intruded by a major gabbroic body and several generations of dykes. To the south the metasupracrustals gradually transform into the Risemedet migmatites. In western Mühlig-Hofmannfjella the bedrock is dominated by the large Svarthamaren Charnockite batholith. The batholith is bordered by the Snøtoa metamorphic complex outcropping to the south and west in Mühlig-Hofmannfjella and it is characterized by a high content of partly assimilated country rock inclusions. Mineral paragenesis and geothermometry/geobarometry suggest a two-stage tectonothermal-igneous history with an initial intermediate pressure, upper amphibolite to granulite facies metamorphism followed by high temperature transformations related to the charnockite intrusion. The age of the initial tectonothermal event is probably about 1,100 Ma. Geochronological work in the present study (Rb/Sr whole rock) gave an age of 500 ± 24 Ma for the Svarthamaren Charnockite, interpreted to record the age of crystallization. Late brittle faulting and undeformed dolerite dykes outcropping in Jutulsessen are believed to be related to Mesozoic crustal stretching in the Jutulstraumen-Pencksøkket Rift Zone to the west. Article in Journal/Newspaper Antarc* Antarctic Antarctica Dronning Maud Land East Antarctica Polar Research Polar Research (E-Journal) Antarctic East Antarctica Dronning Maud Land Jutulstraumen ENVELOPE(-1.000,-1.000,-72.000,-72.000) Gjelsvikfjella ENVELOPE(2.833,2.833,-72.083,-72.083) Svarthamaren ENVELOPE(3.423,3.423,-54.438,-54.438) Jutulsessen ENVELOPE(2.750,2.750,-72.017,-72.017) Mühlig-Hofmannfjella ENVELOPE(5.500,5.500,-72.000,-72.000) Pencksøkket ENVELOPE(-2.750,-2.750,-73.000,-73.000) Snøtoa ENVELOPE(4.583,4.583,-71.950,-71.950) Polar Research 8 2 99 126 |
institution |
Open Polar |
collection |
Polar Research (E-Journal) |
op_collection_id |
ftjpolarres |
language |
English |
description |
As a part of the Norwegian Antarctic Research Expedition 1984/85, geological mapping was performed in Gjelsvikfjella and western Mühlig-Hofmannfjella, Dronning Maud Land. The northern part of Gjelsvikfjella is dominated by the Jutulsessen metasupracrustals which have been intruded by a major gabbroic body and several generations of dykes. To the south the metasupracrustals gradually transform into the Risemedet migmatites. In western Mühlig-Hofmannfjella the bedrock is dominated by the large Svarthamaren Charnockite batholith. The batholith is bordered by the Snøtoa metamorphic complex outcropping to the south and west in Mühlig-Hofmannfjella and it is characterized by a high content of partly assimilated country rock inclusions. Mineral paragenesis and geothermometry/geobarometry suggest a two-stage tectonothermal-igneous history with an initial intermediate pressure, upper amphibolite to granulite facies metamorphism followed by high temperature transformations related to the charnockite intrusion. The age of the initial tectonothermal event is probably about 1,100 Ma. Geochronological work in the present study (Rb/Sr whole rock) gave an age of 500 ± 24 Ma for the Svarthamaren Charnockite, interpreted to record the age of crystallization. Late brittle faulting and undeformed dolerite dykes outcropping in Jutulsessen are believed to be related to Mesozoic crustal stretching in the Jutulstraumen-Pencksøkket Rift Zone to the west. |
format |
Article in Journal/Newspaper |
author |
Ohta, Y. Tørudbakken, B. O. Shiraishi, K. |
spellingShingle |
Ohta, Y. Tørudbakken, B. O. Shiraishi, K. Geology of Gjelsvikfjella and western Mühlig-Hofmannfjella, Dronning Maud Land, east Antarctica |
author_facet |
Ohta, Y. Tørudbakken, B. O. Shiraishi, K. |
author_sort |
Ohta, Y. |
title |
Geology of Gjelsvikfjella and western Mühlig-Hofmannfjella, Dronning Maud Land, east Antarctica |
title_short |
Geology of Gjelsvikfjella and western Mühlig-Hofmannfjella, Dronning Maud Land, east Antarctica |
title_full |
Geology of Gjelsvikfjella and western Mühlig-Hofmannfjella, Dronning Maud Land, east Antarctica |
title_fullStr |
Geology of Gjelsvikfjella and western Mühlig-Hofmannfjella, Dronning Maud Land, east Antarctica |
title_full_unstemmed |
Geology of Gjelsvikfjella and western Mühlig-Hofmannfjella, Dronning Maud Land, east Antarctica |
title_sort |
geology of gjelsvikfjella and western mühlig-hofmannfjella, dronning maud land, east antarctica |
publisher |
Norwegian Polar Institute |
publishDate |
1990 |
url |
https://polarresearch.net/index.php/polar/article/view/2380 https://doi.org/10.3402/polar.v8i2.6808 |
long_lat |
ENVELOPE(-1.000,-1.000,-72.000,-72.000) ENVELOPE(2.833,2.833,-72.083,-72.083) ENVELOPE(3.423,3.423,-54.438,-54.438) ENVELOPE(2.750,2.750,-72.017,-72.017) ENVELOPE(5.500,5.500,-72.000,-72.000) ENVELOPE(-2.750,-2.750,-73.000,-73.000) ENVELOPE(4.583,4.583,-71.950,-71.950) |
geographic |
Antarctic East Antarctica Dronning Maud Land Jutulstraumen Gjelsvikfjella Svarthamaren Jutulsessen Mühlig-Hofmannfjella Pencksøkket Snøtoa |
geographic_facet |
Antarctic East Antarctica Dronning Maud Land Jutulstraumen Gjelsvikfjella Svarthamaren Jutulsessen Mühlig-Hofmannfjella Pencksøkket Snøtoa |
genre |
Antarc* Antarctic Antarctica Dronning Maud Land East Antarctica Polar Research |
genre_facet |
Antarc* Antarctic Antarctica Dronning Maud Land East Antarctica Polar Research |
op_source |
Polar Research; Vol. 8 No. 2 (1990); 99-126 1751-8369 |
op_relation |
https://polarresearch.net/index.php/polar/article/view/2380/5630 https://polarresearch.net/index.php/polar/article/view/2380 doi:10.3402/polar.v8i2.6808 |
op_rights |
Copyright (c) 2018 Polar Research |
op_doi |
https://doi.org/10.3402/polar.v8i2.6808 |
container_title |
Polar Research |
container_volume |
8 |
container_issue |
2 |
container_start_page |
99 |
op_container_end_page |
126 |
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1766271083331190784 |