Complex calc-alkaline volcanism recorded in Mesoarchaean supracrustal belts north of Frederikshab Isblink, southern West Greenland: Implications for subduction zone processes in the early Earth
We present new geochemical data for three Mesoarchaean supracrustal belts (Ravns Storo, Bjornesund and Perserajoorsuaq) situated north of Frederikshab Isblink in southern West Greenland for which we propose the collective name 'The Ikkattup Nunaa Supracrustal Association'. They comprise ma...
Published in: | Precambrian Research |
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Language: | English |
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Elsevier
2012
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Online Access: | https://lup.lub.lu.se/record/2883984 https://doi.org/10.1016/j.precamres.2012.03.013 |
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ftulundlup:oai:lup.lub.lu.se:1d654b5d-c765-4bc1-81bf-c97ba2b72548 2023-05-15T16:28:02+02:00 Complex calc-alkaline volcanism recorded in Mesoarchaean supracrustal belts north of Frederikshab Isblink, southern West Greenland: Implications for subduction zone processes in the early Earth Szilas, Kristoffer Hoffmann, J. Elis Scherstén, Anders Rosing, Minik T. Windley, Brian F. Kokfelt, Thomas F. Keulen, Nynke van Hinsberg, Vincent J. Naeraa, Tomas Frei, Robert Muenker, Carsten 2012 https://lup.lub.lu.se/record/2883984 https://doi.org/10.1016/j.precamres.2012.03.013 eng eng Elsevier https://lup.lub.lu.se/record/2883984 http://dx.doi.org/10.1016/j.precamres.2012.03.013 wos:000305380300006 scopus:84860316460 Precambrian Research; 208, pp 90-123 (2012) ISSN: 0301-9268 Geology Archaean Supracrustal belt Calc-alkaline volcanism The Ikkattup Nunaa Supracrustal Association Southern West Greenland contributiontojournal/article info:eu-repo/semantics/article text 2012 ftulundlup https://doi.org/10.1016/j.precamres.2012.03.013 2023-02-01T23:28:58Z We present new geochemical data for three Mesoarchaean supracrustal belts (Ravns Storo, Bjornesund and Perserajoorsuaq) situated north of Frederikshab Isblink in southern West Greenland for which we propose the collective name 'The Ikkattup Nunaa Supracrustal Association'. They comprise mainly amphibolites of tholeiitic basalt composition and leucoamphibolites of calc-alkaline andesite composition. Both lithological units are cut by aplite sheets of tonalite-trondhjemite-granodiorite (TTG) composition with U-Pb zircon ages of c. 2900 Ma. Lu-Hf and Sm-Nd isochrons based on whole rock amphibolite and leucoamphibolite samples yield ages of 2990 +/- 41 Ma and 3020 +/- 78 Ma, respectively, which are within error of the age of the Fiskenaesset Complex situated 5-25 km to the north. Leucoamphibolites from the three supracrustal belts show apparent geochemical mixing trends between tholeiitic amphibolites and TTG gneisses, as the end-members. By assimilation-fractional-crystallisation (AFC) modelling we can show that one group of leucoamphibolites can indeed be explained by contamination of the parental melts by a TTG-like end-member and another group of high P2O5, La and Nb leucoamphibolites can be explained by contamination involving a hypothetical low-silica adakite end-member. However, the leucoamphibolites are juvenile with epsilon Nd-(2970 Ma) from +2.1 to +3.5 and epsilon Hf-(2970 (Ma)) of +3.5 to +4.3. Thus, the mafic source of the felsic contaminant melts must have been derived from a depleted mantle source more or less at the same time (<60 Ma) as the volcanism took place. Our preferred interpretation of the geochemical and isotope data is that the protoliths of the supracrustal rocks formed in an island arc setting, where early tholeiitic volcanism gave way to calc-alkaline volcanism in a maturing arc. The apparent AFC trends are thus explained by in situ partial melting of basaltic arc crust to form juvenile TTG- and adakite-melts that mixed with mafic magmas or contaminated their mantle source to produce ... Article in Journal/Newspaper Greenland Lund University Publications (LUP) Greenland Precambrian Research 208-211 90 123 |
institution |
Open Polar |
collection |
Lund University Publications (LUP) |
op_collection_id |
ftulundlup |
language |
English |
topic |
Geology Archaean Supracrustal belt Calc-alkaline volcanism The Ikkattup Nunaa Supracrustal Association Southern West Greenland |
spellingShingle |
Geology Archaean Supracrustal belt Calc-alkaline volcanism The Ikkattup Nunaa Supracrustal Association Southern West Greenland Szilas, Kristoffer Hoffmann, J. Elis Scherstén, Anders Rosing, Minik T. Windley, Brian F. Kokfelt, Thomas F. Keulen, Nynke van Hinsberg, Vincent J. Naeraa, Tomas Frei, Robert Muenker, Carsten Complex calc-alkaline volcanism recorded in Mesoarchaean supracrustal belts north of Frederikshab Isblink, southern West Greenland: Implications for subduction zone processes in the early Earth |
topic_facet |
Geology Archaean Supracrustal belt Calc-alkaline volcanism The Ikkattup Nunaa Supracrustal Association Southern West Greenland |
description |
We present new geochemical data for three Mesoarchaean supracrustal belts (Ravns Storo, Bjornesund and Perserajoorsuaq) situated north of Frederikshab Isblink in southern West Greenland for which we propose the collective name 'The Ikkattup Nunaa Supracrustal Association'. They comprise mainly amphibolites of tholeiitic basalt composition and leucoamphibolites of calc-alkaline andesite composition. Both lithological units are cut by aplite sheets of tonalite-trondhjemite-granodiorite (TTG) composition with U-Pb zircon ages of c. 2900 Ma. Lu-Hf and Sm-Nd isochrons based on whole rock amphibolite and leucoamphibolite samples yield ages of 2990 +/- 41 Ma and 3020 +/- 78 Ma, respectively, which are within error of the age of the Fiskenaesset Complex situated 5-25 km to the north. Leucoamphibolites from the three supracrustal belts show apparent geochemical mixing trends between tholeiitic amphibolites and TTG gneisses, as the end-members. By assimilation-fractional-crystallisation (AFC) modelling we can show that one group of leucoamphibolites can indeed be explained by contamination of the parental melts by a TTG-like end-member and another group of high P2O5, La and Nb leucoamphibolites can be explained by contamination involving a hypothetical low-silica adakite end-member. However, the leucoamphibolites are juvenile with epsilon Nd-(2970 Ma) from +2.1 to +3.5 and epsilon Hf-(2970 (Ma)) of +3.5 to +4.3. Thus, the mafic source of the felsic contaminant melts must have been derived from a depleted mantle source more or less at the same time (<60 Ma) as the volcanism took place. Our preferred interpretation of the geochemical and isotope data is that the protoliths of the supracrustal rocks formed in an island arc setting, where early tholeiitic volcanism gave way to calc-alkaline volcanism in a maturing arc. The apparent AFC trends are thus explained by in situ partial melting of basaltic arc crust to form juvenile TTG- and adakite-melts that mixed with mafic magmas or contaminated their mantle source to produce ... |
format |
Article in Journal/Newspaper |
author |
Szilas, Kristoffer Hoffmann, J. Elis Scherstén, Anders Rosing, Minik T. Windley, Brian F. Kokfelt, Thomas F. Keulen, Nynke van Hinsberg, Vincent J. Naeraa, Tomas Frei, Robert Muenker, Carsten |
author_facet |
Szilas, Kristoffer Hoffmann, J. Elis Scherstén, Anders Rosing, Minik T. Windley, Brian F. Kokfelt, Thomas F. Keulen, Nynke van Hinsberg, Vincent J. Naeraa, Tomas Frei, Robert Muenker, Carsten |
author_sort |
Szilas, Kristoffer |
title |
Complex calc-alkaline volcanism recorded in Mesoarchaean supracrustal belts north of Frederikshab Isblink, southern West Greenland: Implications for subduction zone processes in the early Earth |
title_short |
Complex calc-alkaline volcanism recorded in Mesoarchaean supracrustal belts north of Frederikshab Isblink, southern West Greenland: Implications for subduction zone processes in the early Earth |
title_full |
Complex calc-alkaline volcanism recorded in Mesoarchaean supracrustal belts north of Frederikshab Isblink, southern West Greenland: Implications for subduction zone processes in the early Earth |
title_fullStr |
Complex calc-alkaline volcanism recorded in Mesoarchaean supracrustal belts north of Frederikshab Isblink, southern West Greenland: Implications for subduction zone processes in the early Earth |
title_full_unstemmed |
Complex calc-alkaline volcanism recorded in Mesoarchaean supracrustal belts north of Frederikshab Isblink, southern West Greenland: Implications for subduction zone processes in the early Earth |
title_sort |
complex calc-alkaline volcanism recorded in mesoarchaean supracrustal belts north of frederikshab isblink, southern west greenland: implications for subduction zone processes in the early earth |
publisher |
Elsevier |
publishDate |
2012 |
url |
https://lup.lub.lu.se/record/2883984 https://doi.org/10.1016/j.precamres.2012.03.013 |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Greenland |
genre_facet |
Greenland |
op_source |
Precambrian Research; 208, pp 90-123 (2012) ISSN: 0301-9268 |
op_relation |
https://lup.lub.lu.se/record/2883984 http://dx.doi.org/10.1016/j.precamres.2012.03.013 wos:000305380300006 scopus:84860316460 |
op_doi |
https://doi.org/10.1016/j.precamres.2012.03.013 |
container_title |
Precambrian Research |
container_volume |
208-211 |
container_start_page |
90 |
op_container_end_page |
123 |
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1766017649982046208 |