Grenvillian magmatism of western and central Nordaustlandet, northeastern Svalbard
Abstract The basement of the island of Nordaustlandet, northeastern Svalbard, consists of a complex of metasedimentary and metavolcanic rocks, granites and augen gneisses, unconformably overlain by the Neoproterozoic Murchisonfjorden Supergroup. Earlier U-Pb dating of the Laponiafjellet and Kontaktb...
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1999
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crcambridgeupr:10.1017/s0263593300002583 2024-05-19T07:44:21+00:00 Grenvillian magmatism of western and central Nordaustlandet, northeastern Svalbard Johansson, Åke Larionov, Alexander N. Tebenkov, Alexander M. Gee, David G. Whitehouse, Martin J. Vestin, Jessica 1999 http://dx.doi.org/10.1017/s0263593300002583 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0263593300002583 en eng Cambridge University Press (CUP) https://www.cambridge.org/core/terms Transactions of the Royal Society of Edinburgh: Earth Sciences volume 90, issue 3, page 221-254 ISSN 0263-5933 1473-7116 journal-article 1999 crcambridgeupr https://doi.org/10.1017/s0263593300002583 2024-05-02T06:51:06Z Abstract The basement of the island of Nordaustlandet, northeastern Svalbard, consists of a complex of metasedimentary and metavolcanic rocks, granites and augen gneisses, unconformably overlain by the Neoproterozoic Murchisonfjorden Supergroup. Earlier U-Pb dating of the Laponiafjellet and Kontaktberget granites has shown them to be late Grenvillian, with ages of c. 960 Ma and 940 Ma, respectively. Here, we present conventional U-Pb zircon and monazite data, single zircon Pb-evaporation data and ion microprobe data from the Kapp Hansteen Group and Svartrabbane Formation volcanic and subvolcanic rocks, and from the Fonndalen and Ringåsvatnet augen gneisses of central Nordaustlandet. The combined evidence suggests late Grenvillian magmatic ages of 940–970 Ma for all these rocks, with inherited zircons ranging in age from c. 1200 Ma to 2600 Ma. The investigated rocks vary in chemical composition from andesites to rhyolites and granites, and show generally similar trace and rare earth element patterns, with trace element compositions suggesting a volcanic arc or syn-collisional tectonic setting, and major element compositions suggesting a large sedimentary input to the magmas. Contributions from older crustal material are also supported by Nd isotope data and the presence of inherited zircons. The Grenvillian magmatic rocks thus originated in a series of magmatic events along a continental margin over a time span not longer than 30 Ma. The volcanic rocks were extruded onto folded strata of the Brennevinsfjorden Group–Helvetesflya Formation, which must have been deposited in the time interval 1200–960 Ma. Folding of the metasediments preceded the volcanism, but was synchronous with intrusion of the augen gneiss protolith, and was followed by crustal stabilisation, uplift and erosion. This newly formed Grenvillian crust then served as basement for the deposition of the Neoproterozoic Murchisonfjorden Supergroup. The present outcrop pattern of the Grenvillian rocks is largely the result of large-scale Caledonian ... Article in Journal/Newspaper Nordaustlandet Svalbard Cambridge University Press Transactions of the Royal Society of Edinburgh: Earth Sciences 90 3 221 254 |
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Cambridge University Press |
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English |
description |
Abstract The basement of the island of Nordaustlandet, northeastern Svalbard, consists of a complex of metasedimentary and metavolcanic rocks, granites and augen gneisses, unconformably overlain by the Neoproterozoic Murchisonfjorden Supergroup. Earlier U-Pb dating of the Laponiafjellet and Kontaktberget granites has shown them to be late Grenvillian, with ages of c. 960 Ma and 940 Ma, respectively. Here, we present conventional U-Pb zircon and monazite data, single zircon Pb-evaporation data and ion microprobe data from the Kapp Hansteen Group and Svartrabbane Formation volcanic and subvolcanic rocks, and from the Fonndalen and Ringåsvatnet augen gneisses of central Nordaustlandet. The combined evidence suggests late Grenvillian magmatic ages of 940–970 Ma for all these rocks, with inherited zircons ranging in age from c. 1200 Ma to 2600 Ma. The investigated rocks vary in chemical composition from andesites to rhyolites and granites, and show generally similar trace and rare earth element patterns, with trace element compositions suggesting a volcanic arc or syn-collisional tectonic setting, and major element compositions suggesting a large sedimentary input to the magmas. Contributions from older crustal material are also supported by Nd isotope data and the presence of inherited zircons. The Grenvillian magmatic rocks thus originated in a series of magmatic events along a continental margin over a time span not longer than 30 Ma. The volcanic rocks were extruded onto folded strata of the Brennevinsfjorden Group–Helvetesflya Formation, which must have been deposited in the time interval 1200–960 Ma. Folding of the metasediments preceded the volcanism, but was synchronous with intrusion of the augen gneiss protolith, and was followed by crustal stabilisation, uplift and erosion. This newly formed Grenvillian crust then served as basement for the deposition of the Neoproterozoic Murchisonfjorden Supergroup. The present outcrop pattern of the Grenvillian rocks is largely the result of large-scale Caledonian ... |
format |
Article in Journal/Newspaper |
author |
Johansson, Åke Larionov, Alexander N. Tebenkov, Alexander M. Gee, David G. Whitehouse, Martin J. Vestin, Jessica |
spellingShingle |
Johansson, Åke Larionov, Alexander N. Tebenkov, Alexander M. Gee, David G. Whitehouse, Martin J. Vestin, Jessica Grenvillian magmatism of western and central Nordaustlandet, northeastern Svalbard |
author_facet |
Johansson, Åke Larionov, Alexander N. Tebenkov, Alexander M. Gee, David G. Whitehouse, Martin J. Vestin, Jessica |
author_sort |
Johansson, Åke |
title |
Grenvillian magmatism of western and central Nordaustlandet, northeastern Svalbard |
title_short |
Grenvillian magmatism of western and central Nordaustlandet, northeastern Svalbard |
title_full |
Grenvillian magmatism of western and central Nordaustlandet, northeastern Svalbard |
title_fullStr |
Grenvillian magmatism of western and central Nordaustlandet, northeastern Svalbard |
title_full_unstemmed |
Grenvillian magmatism of western and central Nordaustlandet, northeastern Svalbard |
title_sort |
grenvillian magmatism of western and central nordaustlandet, northeastern svalbard |
publisher |
Cambridge University Press (CUP) |
publishDate |
1999 |
url |
http://dx.doi.org/10.1017/s0263593300002583 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0263593300002583 |
genre |
Nordaustlandet Svalbard |
genre_facet |
Nordaustlandet Svalbard |
op_source |
Transactions of the Royal Society of Edinburgh: Earth Sciences volume 90, issue 3, page 221-254 ISSN 0263-5933 1473-7116 |
op_rights |
https://www.cambridge.org/core/terms |
op_doi |
https://doi.org/10.1017/s0263593300002583 |
container_title |
Transactions of the Royal Society of Edinburgh: Earth Sciences |
container_volume |
90 |
container_issue |
3 |
container_start_page |
221 |
op_container_end_page |
254 |
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1799484132612374528 |