An orphaned baltic terrane in the Greenland caledonides:a Sm-Nd and detrital zircon study of a high-pressure/ultrahigh-pressure complex in Liverpool land
Liverpool Land, at the southern tip of the Greenland Caledonides, exposes a composite metamorphic terrane: the midcrustal granulite-facies Jaettedal Complex tectonically juxtaposed against the eclogite-facies, peridotite-bearing Tvaerdal Complex. The Jaettedal Complex is a Laurentian terrane, wherea...
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ftmacquarieunicr:oai:https://researchers.mq.edu.au:publications/e14cedf8-70fe-45f0-844f-8796875f1238 2024-09-15T18:09:36+00:00 An orphaned baltic terrane in the Greenland caledonides:a Sm-Nd and detrital zircon study of a high-pressure/ultrahigh-pressure complex in Liverpool land Brueckner, H. K. Medaris, L. G. Belousova, E. A. Johnston, S. M. Griffin, W. L. Hartz, E. H. Hemming, S. Ghent, E. Bubbico, R. 2016-09-01 https://researchers.mq.edu.au/en/publications/e14cedf8-70fe-45f0-844f-8796875f1238 https://doi.org/10.1086/687552 http://www.scopus.com/inward/record.url?scp=84988878631&partnerID=8YFLogxK eng eng info:eu-repo/semantics/closedAccess Brueckner , H K , Medaris , L G , Belousova , E A , Johnston , S M , Griffin , W L , Hartz , E H , Hemming , S , Ghent , E & Bubbico , R 2016 , ' An orphaned baltic terrane in the Greenland caledonides : a Sm-Nd and detrital zircon study of a high-pressure/ultrahigh-pressure complex in Liverpool land ' , Journal of Geology , vol. 124 , no. 5 , pp. 541-567 . https://doi.org/10.1086/687552 article 2016 ftmacquarieunicr https://doi.org/10.1086/687552 2024-07-10T23:45:58Z Liverpool Land, at the southern tip of the Greenland Caledonides, exposes a composite metamorphic terrane: the midcrustal granulite-facies Jaettedal Complex tectonically juxtaposed against the eclogite-facies, peridotite-bearing Tvaerdal Complex. The Jaettedal Complex is a Laurentian terrane, whereas the Tvaerdal Complex was proposed by earlier investigators to be a Baltic terrane. PT estimates (8807–9207C at 35–40 kbar) and Sm-Nd mineral isochrons from Tvaerdal eclogites indicate that recrystallization occurred under ultrahigh-pressure (UHP) metamorphic conditions ≈400 m.yr. ago, the same time and under similar conditions as the Western Gneiss Complex of the Norwegian Caledonides. Detrital zircons from the Tvaerdal Complex, analyzed for U-Pb, Lu-Hf, and trace elements by laser ablation inductively coupled plasma mass spectrometry, give concordantMesoproterozoic ages but not the Archean and ≈1.8 Ga Proterozoic ages characteristic of Laurentian terranes. Most remaining concordant U-Pb ages are 411–375Ma (i.e., Scandian), which contrast with older (≈460–410 Ma) zircon ages from the Jaettedal Complex as well as other Laurentian terranes. Both the Precambrian and the Scandian age sets confirm the Tvaerdal Complex as an orphaned Baltic terrane. The Jaettedal Complex underwent a lengthy Caledonian history as part of a continental arc systemduring the closure of Iapetus, whereas the Tvaerdal Complex was a fragment of the approaching Baltic passive margin. UHP metamorphism occurred when this margin subducted into the mantle beneath Laurentia. We propose that the Tvaerdal Complex separated fromBaltica and rose through the hot mantle wedge to the base of the overriding Laurentian crust by diapirism, a process that may explain its abundant anatectic granitoid intrusions. Article in Journal/Newspaper Greenland Macquarie University Research Portal The Journal of Geology 124 5 541 567 |
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Open Polar |
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Macquarie University Research Portal |
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ftmacquarieunicr |
language |
English |
description |
Liverpool Land, at the southern tip of the Greenland Caledonides, exposes a composite metamorphic terrane: the midcrustal granulite-facies Jaettedal Complex tectonically juxtaposed against the eclogite-facies, peridotite-bearing Tvaerdal Complex. The Jaettedal Complex is a Laurentian terrane, whereas the Tvaerdal Complex was proposed by earlier investigators to be a Baltic terrane. PT estimates (8807–9207C at 35–40 kbar) and Sm-Nd mineral isochrons from Tvaerdal eclogites indicate that recrystallization occurred under ultrahigh-pressure (UHP) metamorphic conditions ≈400 m.yr. ago, the same time and under similar conditions as the Western Gneiss Complex of the Norwegian Caledonides. Detrital zircons from the Tvaerdal Complex, analyzed for U-Pb, Lu-Hf, and trace elements by laser ablation inductively coupled plasma mass spectrometry, give concordantMesoproterozoic ages but not the Archean and ≈1.8 Ga Proterozoic ages characteristic of Laurentian terranes. Most remaining concordant U-Pb ages are 411–375Ma (i.e., Scandian), which contrast with older (≈460–410 Ma) zircon ages from the Jaettedal Complex as well as other Laurentian terranes. Both the Precambrian and the Scandian age sets confirm the Tvaerdal Complex as an orphaned Baltic terrane. The Jaettedal Complex underwent a lengthy Caledonian history as part of a continental arc systemduring the closure of Iapetus, whereas the Tvaerdal Complex was a fragment of the approaching Baltic passive margin. UHP metamorphism occurred when this margin subducted into the mantle beneath Laurentia. We propose that the Tvaerdal Complex separated fromBaltica and rose through the hot mantle wedge to the base of the overriding Laurentian crust by diapirism, a process that may explain its abundant anatectic granitoid intrusions. |
format |
Article in Journal/Newspaper |
author |
Brueckner, H. K. Medaris, L. G. Belousova, E. A. Johnston, S. M. Griffin, W. L. Hartz, E. H. Hemming, S. Ghent, E. Bubbico, R. |
spellingShingle |
Brueckner, H. K. Medaris, L. G. Belousova, E. A. Johnston, S. M. Griffin, W. L. Hartz, E. H. Hemming, S. Ghent, E. Bubbico, R. An orphaned baltic terrane in the Greenland caledonides:a Sm-Nd and detrital zircon study of a high-pressure/ultrahigh-pressure complex in Liverpool land |
author_facet |
Brueckner, H. K. Medaris, L. G. Belousova, E. A. Johnston, S. M. Griffin, W. L. Hartz, E. H. Hemming, S. Ghent, E. Bubbico, R. |
author_sort |
Brueckner, H. K. |
title |
An orphaned baltic terrane in the Greenland caledonides:a Sm-Nd and detrital zircon study of a high-pressure/ultrahigh-pressure complex in Liverpool land |
title_short |
An orphaned baltic terrane in the Greenland caledonides:a Sm-Nd and detrital zircon study of a high-pressure/ultrahigh-pressure complex in Liverpool land |
title_full |
An orphaned baltic terrane in the Greenland caledonides:a Sm-Nd and detrital zircon study of a high-pressure/ultrahigh-pressure complex in Liverpool land |
title_fullStr |
An orphaned baltic terrane in the Greenland caledonides:a Sm-Nd and detrital zircon study of a high-pressure/ultrahigh-pressure complex in Liverpool land |
title_full_unstemmed |
An orphaned baltic terrane in the Greenland caledonides:a Sm-Nd and detrital zircon study of a high-pressure/ultrahigh-pressure complex in Liverpool land |
title_sort |
orphaned baltic terrane in the greenland caledonides:a sm-nd and detrital zircon study of a high-pressure/ultrahigh-pressure complex in liverpool land |
publishDate |
2016 |
url |
https://researchers.mq.edu.au/en/publications/e14cedf8-70fe-45f0-844f-8796875f1238 https://doi.org/10.1086/687552 http://www.scopus.com/inward/record.url?scp=84988878631&partnerID=8YFLogxK |
genre |
Greenland |
genre_facet |
Greenland |
op_source |
Brueckner , H K , Medaris , L G , Belousova , E A , Johnston , S M , Griffin , W L , Hartz , E H , Hemming , S , Ghent , E & Bubbico , R 2016 , ' An orphaned baltic terrane in the Greenland caledonides : a Sm-Nd and detrital zircon study of a high-pressure/ultrahigh-pressure complex in Liverpool land ' , Journal of Geology , vol. 124 , no. 5 , pp. 541-567 . https://doi.org/10.1086/687552 |
op_rights |
info:eu-repo/semantics/closedAccess |
op_doi |
https://doi.org/10.1086/687552 |
container_title |
The Journal of Geology |
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124 |
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5 |
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541 |
op_container_end_page |
567 |
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1810447173412716544 |