Detrital garnet petrology challenges Paleoproterozoic ultrahigh-pressure metamorphism in western Greenland
Abstract. Modern-style plate tectonics is characterised by the global operation of cold and deep subduction involving blueschist facies and ultrahigh-pressure metamorphism. This has been a common process since the Neoproterozoic, but a couple of studies indicate similar processes were active in the...
Published in: | European Journal of Mineralogy |
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ftsubgoettingen:oai:publications.goettingen-research-online.de:2/132201 2023-10-01T03:56:20+02:00 Detrital garnet petrology challenges Paleoproterozoic ultrahigh-pressure metamorphism in western Greenland Schönig, Jan Benner, Carsten Meinhold, Guido von Eynatten, Hilmar Lünsdorf, N. Keno Schönig, Jan Benner, Carsten Meinhold, Guido von Eynatten, Hilmar Lünsdorf, N. Keno 2023 https://resolver.sub.uni-goettingen.de/purl?gro-2/132201 https://doi.org/10.5194/ejm-35-479-2023 en eng https://resolver.sub.uni-goettingen.de/purl?gro-2/132201 doi:10.5194/ejm-35-479-2023 info:eu-repo/semantics/article journal_article yes 2023 ftsubgoettingen https://doi.org/10.5194/ejm-35-479-2023 2023-09-03T22:12:23Z Abstract. Modern-style plate tectonics is characterised by the global operation of cold and deep subduction involving blueschist facies and ultrahigh-pressure metamorphism. This has been a common process since the Neoproterozoic, but a couple of studies indicate similar processes were active in the Paleoproterozoic, at least on the local scale. Particularly conspicuous are extreme ultrahigh-pressure conditions of ∼ 7 GPa at thermal gradients < 150 ∘C GPa−1 proposed for metamorphic rocks of the Nordre Strømfjord shear zone in the western part of the Paleoproterozoic Nagssugtoqidian Orogen of Greenland. By acquiring a large dataset of heavy minerals (n = 52 130) and garnet major-element composition integrated with mineral inclusion analysis (n=2669) from modern sands representing fresh and naturally mixed erosional material from the metamorphic rocks, we here intensely screened the area for potential occurrences of ultrahigh-pressure rocks and put constraints on the metamorphic evolution. Apart from the absence of any indications pointing to ultrahigh-pressure and low-temperature–high-pressure metamorphism, the results are well in accordance with a common Paleoproterozoic subduction–collision metamorphic evolution along a Barrovian-type intermediate temperature and pressure gradient with a pressure peak at the amphibolite–granulite–eclogite-facies transition and a temperature peak at medium- to high-pressure granulite-facies conditions. In addition, we discuss that all “evidence” for ultrahigh-pressure metamorphism proposed in the literature for rocks of this area is equivocal. Accordingly, the Nordre Strømfjord shear zone is not an example of modern-style plate tectonics in the Paleoproterozoic or of very low thermal gradients and extreme pressure conditions in general. Article in Journal/Newspaper Greenland Nordre strømfjord Georg-August-Universität Göttingen: GoeScholar Greenland Nordre Strømfjord ENVELOPE(-52.500,-52.500,67.533,67.533) European Journal of Mineralogy 35 4 479 498 |
institution |
Open Polar |
collection |
Georg-August-Universität Göttingen: GoeScholar |
op_collection_id |
ftsubgoettingen |
language |
English |
description |
Abstract. Modern-style plate tectonics is characterised by the global operation of cold and deep subduction involving blueschist facies and ultrahigh-pressure metamorphism. This has been a common process since the Neoproterozoic, but a couple of studies indicate similar processes were active in the Paleoproterozoic, at least on the local scale. Particularly conspicuous are extreme ultrahigh-pressure conditions of ∼ 7 GPa at thermal gradients < 150 ∘C GPa−1 proposed for metamorphic rocks of the Nordre Strømfjord shear zone in the western part of the Paleoproterozoic Nagssugtoqidian Orogen of Greenland. By acquiring a large dataset of heavy minerals (n = 52 130) and garnet major-element composition integrated with mineral inclusion analysis (n=2669) from modern sands representing fresh and naturally mixed erosional material from the metamorphic rocks, we here intensely screened the area for potential occurrences of ultrahigh-pressure rocks and put constraints on the metamorphic evolution. Apart from the absence of any indications pointing to ultrahigh-pressure and low-temperature–high-pressure metamorphism, the results are well in accordance with a common Paleoproterozoic subduction–collision metamorphic evolution along a Barrovian-type intermediate temperature and pressure gradient with a pressure peak at the amphibolite–granulite–eclogite-facies transition and a temperature peak at medium- to high-pressure granulite-facies conditions. In addition, we discuss that all “evidence” for ultrahigh-pressure metamorphism proposed in the literature for rocks of this area is equivocal. Accordingly, the Nordre Strømfjord shear zone is not an example of modern-style plate tectonics in the Paleoproterozoic or of very low thermal gradients and extreme pressure conditions in general. |
author2 |
Schönig, Jan Benner, Carsten Meinhold, Guido von Eynatten, Hilmar Lünsdorf, N. Keno |
format |
Article in Journal/Newspaper |
author |
Schönig, Jan Benner, Carsten Meinhold, Guido von Eynatten, Hilmar Lünsdorf, N. Keno |
spellingShingle |
Schönig, Jan Benner, Carsten Meinhold, Guido von Eynatten, Hilmar Lünsdorf, N. Keno Detrital garnet petrology challenges Paleoproterozoic ultrahigh-pressure metamorphism in western Greenland |
author_facet |
Schönig, Jan Benner, Carsten Meinhold, Guido von Eynatten, Hilmar Lünsdorf, N. Keno |
author_sort |
Schönig, Jan |
title |
Detrital garnet petrology challenges Paleoproterozoic ultrahigh-pressure metamorphism in western Greenland |
title_short |
Detrital garnet petrology challenges Paleoproterozoic ultrahigh-pressure metamorphism in western Greenland |
title_full |
Detrital garnet petrology challenges Paleoproterozoic ultrahigh-pressure metamorphism in western Greenland |
title_fullStr |
Detrital garnet petrology challenges Paleoproterozoic ultrahigh-pressure metamorphism in western Greenland |
title_full_unstemmed |
Detrital garnet petrology challenges Paleoproterozoic ultrahigh-pressure metamorphism in western Greenland |
title_sort |
detrital garnet petrology challenges paleoproterozoic ultrahigh-pressure metamorphism in western greenland |
publishDate |
2023 |
url |
https://resolver.sub.uni-goettingen.de/purl?gro-2/132201 https://doi.org/10.5194/ejm-35-479-2023 |
long_lat |
ENVELOPE(-52.500,-52.500,67.533,67.533) |
geographic |
Greenland Nordre Strømfjord |
geographic_facet |
Greenland Nordre Strømfjord |
genre |
Greenland Nordre strømfjord |
genre_facet |
Greenland Nordre strømfjord |
op_relation |
https://resolver.sub.uni-goettingen.de/purl?gro-2/132201 doi:10.5194/ejm-35-479-2023 |
op_doi |
https://doi.org/10.5194/ejm-35-479-2023 |
container_title |
European Journal of Mineralogy |
container_volume |
35 |
container_issue |
4 |
container_start_page |
479 |
op_container_end_page |
498 |
_version_ |
1778525770354786304 |