Palaeoproterozoic adakite- and TTG-like magmatism in the Svecofennian orogen, SW Finland
The Palaeoproterozoic Svecofennian orogen in the Fennoscandian shield is an arc accretionary orogen that was formed at c. 1.92-1.86Ga. Arc accretion, magmatism and the subsequent continent-continent collision thickened the crust up to c. 70km, forming one of the thickest Palaeoproterozic orogens. At...
| Autores: | , , , , |
|---|---|
| Tipo de recurso: | artículo |
| Fecha de publicación: | 2012 |
| País: | España |
| Institución: | Universitat Autònoma de Barcelona |
| Repositorio: | Dipòsit Digital de Documents de la UAB |
| Idioma: | inglés |
| OAI Identifier: | oai:ddd.uab.cat:102783 |
| Acceso en línea: | https://ddd.uab.cat/record/102783 https://dx.doi.org/urn:doi:10.1344/105.000001761 |
| Access Level: | acceso abierto |
| Palabra clave: | Adakite TTG Palaeoproterozoic Svecofennian U-Pb Sm-Nd SIMS Diorite Tonalite Trondhjemite Granodiorite Crustal melting |
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Palaeoproterozoic adakite- and TTG-like magmatism in the Svecofennian orogen, SW FinlandVäisänen, M.Johansson, Å.Andersson, U. B.Eklund, O.Hölttä, P.AdakiteTTGPalaeoproterozoicSvecofennianU-PbSm-NdSIMSDioriteTonaliteTrondhjemiteGranodioriteCrustal meltingThe Palaeoproterozoic Svecofennian orogen in the Fennoscandian shield is an arc accretionary orogen that was formed at c. 1.92-1.86Ga. Arc accretion, magmatism and the subsequent continent-continent collision thickened the crust up to c. 70km, forming one of the thickest Palaeoproterozic orogens. At the end stage of accretionary tectonics, voluminous synorogenic magmatism occurred in southwestern Finland leading to the intrusion of intermediate to felsic plutonic rocks. Ion microprobe single zircon dating of one diorite sample yielded an age of 1872±3Ma (eNd=+2.2) and the trondhjemite sample an age of 1867±4Ma (eNd=+2.6). Inherited 2667-1965Ma cores and 1842±5Ma metamorphic rims were also found in zircons from the trondhjemite. The dioritic magmatism is mantle-derived and is slightly enriched by subduction-related processes. The felsic magmatism shows elevated Sr/Y and La/Yb ratios, which are typical for adakite- and TTG-like magmas. Their low Mg#, Ni and Cr contents argue against slab-melting and mantle-wedge contamination. We infer that the felsic magmatism was generated through crustal melting of the lower part of the previously generated volcanic-arc type crust. Based on published melting experiments and the Sr and Y contents of the felsic rocks we suggest that the melts were generated at a minimum pressure of 10kbar, with evidence of a 15kbar pressure for the highest Sr/Y trondhjemites. It is proposed that arc accretion combined with magmatic intrusions thickened the crust so that melting of the lower crust yielded adakite- and TTG-like compositions. The mafic magmatism is considered to be the heat source. 22012-01-0120122012-01-01Articlehttp://purl.org/coar/resource_type/c_6501VoRhttp://purl.org/coar/version/c_970fb48d4fbd8a85info:eu-repo/semantics/articleapplication/pdfhttps://ddd.uab.cat/record/102783https://dx.doi.org/urn:doi:10.1344/105.000001761reponame:Dipòsit Digital de Documents de la UABinstname:Universitat Autònoma de BarcelonaInglésengopen accesshttp://purl.org/coar/access_right/c_abf2Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, sempre i quan aquestes es distribueixin sota la mateixa llicència que regula l'obra original i es reconegui l'autoria.https://creativecommons.org/licenses/by-sa/3.0/info:eu-repo/semantics/openAccessoai:ddd.uab.cat:1027832026-06-06T12:50:31Z |
| dc.title.none.fl_str_mv |
Palaeoproterozoic adakite- and TTG-like magmatism in the Svecofennian orogen, SW Finland |
| title |
Palaeoproterozoic adakite- and TTG-like magmatism in the Svecofennian orogen, SW Finland |
| spellingShingle |
Palaeoproterozoic adakite- and TTG-like magmatism in the Svecofennian orogen, SW Finland Väisänen, M. Adakite TTG Palaeoproterozoic Svecofennian U-Pb Sm-Nd SIMS Diorite Tonalite Trondhjemite Granodiorite Crustal melting |
| title_short |
Palaeoproterozoic adakite- and TTG-like magmatism in the Svecofennian orogen, SW Finland |
| title_full |
Palaeoproterozoic adakite- and TTG-like magmatism in the Svecofennian orogen, SW Finland |
| title_fullStr |
Palaeoproterozoic adakite- and TTG-like magmatism in the Svecofennian orogen, SW Finland |
| title_full_unstemmed |
Palaeoproterozoic adakite- and TTG-like magmatism in the Svecofennian orogen, SW Finland |
| title_sort |
Palaeoproterozoic adakite- and TTG-like magmatism in the Svecofennian orogen, SW Finland |
| dc.creator.none.fl_str_mv |
Väisänen, M. Johansson, Å. Andersson, U. B. Eklund, O. Hölttä, P. |
| author |
Väisänen, M. |
| author_facet |
Väisänen, M. Johansson, Å. Andersson, U. B. Eklund, O. Hölttä, P. |
| author_role |
author |
| author2 |
Johansson, Å. Andersson, U. B. Eklund, O. Hölttä, P. |
| author2_role |
author author author author |
| dc.subject.none.fl_str_mv |
Adakite TTG Palaeoproterozoic Svecofennian U-Pb Sm-Nd SIMS Diorite Tonalite Trondhjemite Granodiorite Crustal melting |
| topic |
Adakite TTG Palaeoproterozoic Svecofennian U-Pb Sm-Nd SIMS Diorite Tonalite Trondhjemite Granodiorite Crustal melting |
| description |
The Palaeoproterozoic Svecofennian orogen in the Fennoscandian shield is an arc accretionary orogen that was formed at c. 1.92-1.86Ga. Arc accretion, magmatism and the subsequent continent-continent collision thickened the crust up to c. 70km, forming one of the thickest Palaeoproterozic orogens. At the end stage of accretionary tectonics, voluminous synorogenic magmatism occurred in southwestern Finland leading to the intrusion of intermediate to felsic plutonic rocks. Ion microprobe single zircon dating of one diorite sample yielded an age of 1872±3Ma (eNd=+2.2) and the trondhjemite sample an age of 1867±4Ma (eNd=+2.6). Inherited 2667-1965Ma cores and 1842±5Ma metamorphic rims were also found in zircons from the trondhjemite. The dioritic magmatism is mantle-derived and is slightly enriched by subduction-related processes. The felsic magmatism shows elevated Sr/Y and La/Yb ratios, which are typical for adakite- and TTG-like magmas. Their low Mg#, Ni and Cr contents argue against slab-melting and mantle-wedge contamination. We infer that the felsic magmatism was generated through crustal melting of the lower part of the previously generated volcanic-arc type crust. Based on published melting experiments and the Sr and Y contents of the felsic rocks we suggest that the melts were generated at a minimum pressure of 10kbar, with evidence of a 15kbar pressure for the highest Sr/Y trondhjemites. It is proposed that arc accretion combined with magmatic intrusions thickened the crust so that melting of the lower crust yielded adakite- and TTG-like compositions. The mafic magmatism is considered to be the heat source. |
| publishDate |
2012 |
| dc.date.none.fl_str_mv |
2 2012-01-01 2012 2012-01-01 |
| dc.type.none.fl_str_mv |
Article http://purl.org/coar/resource_type/c_6501 VoR http://purl.org/coar/version/c_970fb48d4fbd8a85 |
| dc.type.openaire.fl_str_mv |
info:eu-repo/semantics/article |
| format |
article |
| dc.identifier.none.fl_str_mv |
https://ddd.uab.cat/record/102783 https://dx.doi.org/urn:doi:10.1344/105.000001761 |
| url |
https://ddd.uab.cat/record/102783 https://dx.doi.org/urn:doi:10.1344/105.000001761 |
| dc.language.none.fl_str_mv |
Inglés eng |
| language_invalid_str_mv |
Inglés |
| language |
eng |
| dc.rights.none.fl_str_mv |
open access http://purl.org/coar/access_right/c_abf2 https://creativecommons.org/licenses/by-sa/3.0/ |
| dc.rights.openaire.fl_str_mv |
info:eu-repo/semantics/openAccess |
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open access http://purl.org/coar/access_right/c_abf2 https://creativecommons.org/licenses/by-sa/3.0/ |
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openAccess |
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application/pdf |
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reponame:Dipòsit Digital de Documents de la UAB instname:Universitat Autònoma de Barcelona |
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