Geochemical characteristics and tectonic setting of metamorphosed rocks in the Tugela terrane, Natal belt, South Africa
The isotopically juvenile Tugela terrane, part of the Grenvillian Natal belt, southeastern Africa consists of a heterogeneous assemblage of regionally metamorphosed (upper amphibolite facies) mafic and felsic rocks. The Tugela terrane is divisible on the basis of lithology and structural style, from...
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Geological Institute, Yokohama National University/Geological Institute, Yokohama National University/Musashi High School/School of Earth and Ocean Sciences, University of Victoria
2001
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ftnipr:oai:nipr.repo.nii.ac.jp:00002412 2023-05-15T17:10:59+02:00 Geochemical characteristics and tectonic setting of metamorphosed rocks in the Tugela terrane, Natal belt, South Africa Arima,Makoto Tani,Keiji Kawate,Shinichi Johnston, S. T. 2001-07 https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=2412 http://id.nii.ac.jp/1291/00002412/ https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=2412&item_no=1&attribute_id=18&file_no=1 en eng Geological Institute, Yokohama National University/Geological Institute, Yokohama National University/Musashi High School/School of Earth and Ocean Sciences, University of Victoria https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=2412 http://id.nii.ac.jp/1291/00002412/ AA00733561 Memoirs of National Institute of Polar Research. Special issue, 55, 1-39(2001-07) https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=2412&item_no=1&attribute_id=18&file_no=1 Natal Tugela Grenvillian intra-oceanic are South Africa Departmental Bulletin Paper P(論文) 2001 ftnipr 2022-11-12T19:43:14Z The isotopically juvenile Tugela terrane, part of the Grenvillian Natal belt, southeastern Africa consists of a heterogeneous assemblage of regionally metamorphosed (upper amphibolite facies) mafic and felsic rocks. The Tugela terrane is divisible on the basis of lithology and structural style, from east to west, into four major thrust sheets referred to as the Nkomo, Madidima, Mandleni and Tugela sheets, respectively. The Tugela sheet includes the Kotongweni tonalite, a 15km long body of coarsely crystalline garnetiferous hornblende meta-tonalite. Although strongly lineated and foliated, the intrusive contact of the tonalite with its amphibolite wall rocks remains recognizable, as are wallrock xenoliths within the intrusion. Geochemically, the tonalite is extremely depleted with very low abundance of Ta, Nb, rare earth elements (REE) and LIL elements, features considered diagnostic of arc-related igneous rocks. The lithological and geochemical characteristics of the tonalite and its amphibolite wallrocks suggest their formation in an intra-oceanic arc setting comparable to the present day Izu-Bonin arc. In contrast, amphibolites of the underlying Mandleni sheet are characterized by relatively high abundance of Nb, Ti, LIL and HFS elements more similar to the present day oceanic island basalt. The lithologically and geochemically distinct thrust sheets that comprise the oceanic Tugela terrane were each derived from distinct tectonic settings. The Kotongweni tonalite and its wall rocks, preserved in the Tugela sheet, provide a record of middle Proterozoic magmatic arc development prior to the obduction of the Natal belt onto the Kaapvaal craton at about 1.1 Ga. Report Memoirs of National Institute of Polar Research Polar Research National Institute of Polar Research Repository, Japan Wall Rocks ENVELOPE(-129.312,-129.312,52.728,52.728) |
institution |
Open Polar |
collection |
National Institute of Polar Research Repository, Japan |
op_collection_id |
ftnipr |
language |
English |
topic |
Natal Tugela Grenvillian intra-oceanic are South Africa |
spellingShingle |
Natal Tugela Grenvillian intra-oceanic are South Africa Arima,Makoto Tani,Keiji Kawate,Shinichi Johnston, S. T. Geochemical characteristics and tectonic setting of metamorphosed rocks in the Tugela terrane, Natal belt, South Africa |
topic_facet |
Natal Tugela Grenvillian intra-oceanic are South Africa |
description |
The isotopically juvenile Tugela terrane, part of the Grenvillian Natal belt, southeastern Africa consists of a heterogeneous assemblage of regionally metamorphosed (upper amphibolite facies) mafic and felsic rocks. The Tugela terrane is divisible on the basis of lithology and structural style, from east to west, into four major thrust sheets referred to as the Nkomo, Madidima, Mandleni and Tugela sheets, respectively. The Tugela sheet includes the Kotongweni tonalite, a 15km long body of coarsely crystalline garnetiferous hornblende meta-tonalite. Although strongly lineated and foliated, the intrusive contact of the tonalite with its amphibolite wall rocks remains recognizable, as are wallrock xenoliths within the intrusion. Geochemically, the tonalite is extremely depleted with very low abundance of Ta, Nb, rare earth elements (REE) and LIL elements, features considered diagnostic of arc-related igneous rocks. The lithological and geochemical characteristics of the tonalite and its amphibolite wallrocks suggest their formation in an intra-oceanic arc setting comparable to the present day Izu-Bonin arc. In contrast, amphibolites of the underlying Mandleni sheet are characterized by relatively high abundance of Nb, Ti, LIL and HFS elements more similar to the present day oceanic island basalt. The lithologically and geochemically distinct thrust sheets that comprise the oceanic Tugela terrane were each derived from distinct tectonic settings. The Kotongweni tonalite and its wall rocks, preserved in the Tugela sheet, provide a record of middle Proterozoic magmatic arc development prior to the obduction of the Natal belt onto the Kaapvaal craton at about 1.1 Ga. |
format |
Report |
author |
Arima,Makoto Tani,Keiji Kawate,Shinichi Johnston, S. T. |
author_facet |
Arima,Makoto Tani,Keiji Kawate,Shinichi Johnston, S. T. |
author_sort |
Arima,Makoto |
title |
Geochemical characteristics and tectonic setting of metamorphosed rocks in the Tugela terrane, Natal belt, South Africa |
title_short |
Geochemical characteristics and tectonic setting of metamorphosed rocks in the Tugela terrane, Natal belt, South Africa |
title_full |
Geochemical characteristics and tectonic setting of metamorphosed rocks in the Tugela terrane, Natal belt, South Africa |
title_fullStr |
Geochemical characteristics and tectonic setting of metamorphosed rocks in the Tugela terrane, Natal belt, South Africa |
title_full_unstemmed |
Geochemical characteristics and tectonic setting of metamorphosed rocks in the Tugela terrane, Natal belt, South Africa |
title_sort |
geochemical characteristics and tectonic setting of metamorphosed rocks in the tugela terrane, natal belt, south africa |
publisher |
Geological Institute, Yokohama National University/Geological Institute, Yokohama National University/Musashi High School/School of Earth and Ocean Sciences, University of Victoria |
publishDate |
2001 |
url |
https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=2412 http://id.nii.ac.jp/1291/00002412/ https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=2412&item_no=1&attribute_id=18&file_no=1 |
long_lat |
ENVELOPE(-129.312,-129.312,52.728,52.728) |
geographic |
Wall Rocks |
geographic_facet |
Wall Rocks |
genre |
Memoirs of National Institute of Polar Research Polar Research |
genre_facet |
Memoirs of National Institute of Polar Research Polar Research |
op_relation |
https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=2412 http://id.nii.ac.jp/1291/00002412/ AA00733561 Memoirs of National Institute of Polar Research. Special issue, 55, 1-39(2001-07) https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=2412&item_no=1&attribute_id=18&file_no=1 |
_version_ |
1766067810984787968 |