Some new insights into the geochronology of the Western Karelia Subprovince, Finnish Lapland
Archean terranes are generally poorly exposed and structurally complicated, making models of geological evolution difficult to establish. Because of pervasive metamorphism, strong deformation, and poorly exposed bedrock, the stratigraphy, geochronology, and geological evolution of the northeastern p...
| मुख्य लेखकों: | , , , , , , , , , |
|---|---|
| स्वरूप: | लेख |
| भाषा: | English |
| प्रकाशित: |
Geological Society of Finland
2020-06-01
|
| श्रृंखला: | Bulletin of the Geological Society of Finland |
| विषय: | |
| ऑनलाइन पहुंच: | https://www.geologinenseura.fi/sites/geologinenseura.fi/files/bulletin_vol92_1_5-17_2020_tepsell-etal.pdf |
| _version_ | 1830191640012128256 |
|---|---|
| author | Johanna Tepsell O. Tapani Rämö Aku Heinonen Yann Lahaye Pieti Haapala Tapio Halkoaho Jussi S. Heinonen Henri Höytiä Jukka Konnunaho Ville Järvinen |
| author_facet | Johanna Tepsell O. Tapani Rämö Aku Heinonen Yann Lahaye Pieti Haapala Tapio Halkoaho Jussi S. Heinonen Henri Höytiä Jukka Konnunaho Ville Järvinen |
| author_sort | Johanna Tepsell |
| collection | DOAJ |
| description | Archean terranes are generally poorly exposed and structurally complicated, making models of geological evolution difficult to establish. Because of pervasive metamorphism, strong deformation, and poorly exposed bedrock, the stratigraphy, geochronology, and geological evolution of the northeastern part of the Archean Western Karelia Subprovince, Finnish Lapland, is still deficient. Three new U-Pb age determinations were made using the LA-ICP-MS method on zircon in search of more profound understanding of the geochronology of the area. Data from the Pultoselkä granite yield an age of 2795±5 Ma, providing a minimum age of 2.8 Ga for the Tulppio suite. The age is coeval with widespread 2.74–2.70 Ga granitoids of the Karelia Province, likely representing the same magmatic event. The data from the Kontioselkä pegmatite define a maximum age for the pegmatite and a minimum age for mafic volcanic rocks in Kontioselkä at 1781±27 Ma. The age coincides with major deformation and metamorphism in the Karelia Province around 1.76 Ga. Zircon from the Jänesselkä mafic-ultramafic complex yields a minimum age of 2425±17 Ma, complying rather well with the 2.5–2.4 Ga mafic layered intrusions of the northern Fennoscandian Shield. Our new data show that the Archean of the northeastern part of the Western Karelia Subprovince was affected by Proterozoic thermal events more extensively than thus far perceived. |
| first_indexed | 2024-12-17T23:42:29Z |
| format | Article |
| id | doaj.art-9191386d57bd44adb9c20a6ce6bf1e32 |
| institution | Directory Open Access Journal |
| issn | 0367-5211 1799-4632 |
| language | English |
| last_indexed | 2024-12-17T23:42:29Z |
| publishDate | 2020-06-01 |
| publisher | Geological Society of Finland |
| record_format | Article |
| series | Bulletin of the Geological Society of Finland |
| spelling | doaj.art-9191386d57bd44adb9c20a6ce6bf1e322022-12-21T21:28:24ZengGeological Society of FinlandBulletin of the Geological Society of Finland0367-52111799-46322020-06-0192151710.17741/bgsf/92.1.001Some new insights into the geochronology of the Western Karelia Subprovince, Finnish LaplandJohanna Tepsell0O. Tapani Rämö1Aku Heinonen2Yann Lahaye3Pieti Haapala4Tapio Halkoaho5Jussi S. Heinonen6Henri Höytiä7Jukka Konnunaho8Ville Järvinen9Department of Geosciences and Geography, University of Helsinki, FinlandDepartment of Geosciences and Geography, University of HelsinkiDepartment of Geosciences and Geography, University of HelsinkiGeological Survey of Finland, EspooDepartment of Geosciences and Geography, University of Helsinki / A-Insinöörit Civil OyGeological Survey of Finland, KuopioDepartment of Geosciences and Geography, University of Helsinki, FinlandDepartment of Geosciences and Geography, University of Helsinki, Finland / Anglo American Exploration, AA Sakatti Mining OyGeological Survey of Finland, RovaniemiDepartment of Geosciences and Geography, University of Helsinki, FinlandArchean terranes are generally poorly exposed and structurally complicated, making models of geological evolution difficult to establish. Because of pervasive metamorphism, strong deformation, and poorly exposed bedrock, the stratigraphy, geochronology, and geological evolution of the northeastern part of the Archean Western Karelia Subprovince, Finnish Lapland, is still deficient. Three new U-Pb age determinations were made using the LA-ICP-MS method on zircon in search of more profound understanding of the geochronology of the area. Data from the Pultoselkä granite yield an age of 2795±5 Ma, providing a minimum age of 2.8 Ga for the Tulppio suite. The age is coeval with widespread 2.74–2.70 Ga granitoids of the Karelia Province, likely representing the same magmatic event. The data from the Kontioselkä pegmatite define a maximum age for the pegmatite and a minimum age for mafic volcanic rocks in Kontioselkä at 1781±27 Ma. The age coincides with major deformation and metamorphism in the Karelia Province around 1.76 Ga. Zircon from the Jänesselkä mafic-ultramafic complex yields a minimum age of 2425±17 Ma, complying rather well with the 2.5–2.4 Ga mafic layered intrusions of the northern Fennoscandian Shield. Our new data show that the Archean of the northeastern part of the Western Karelia Subprovince was affected by Proterozoic thermal events more extensively than thus far perceived.https://www.geologinenseura.fi/sites/geologinenseura.fi/files/bulletin_vol92_1_5-17_2020_tepsell-etal.pdfgeochronologyu-pbzirconicp-mseastern laplandarcheanfinland2.44 ga mafic layered intrusions |
| spellingShingle | Johanna Tepsell O. Tapani Rämö Aku Heinonen Yann Lahaye Pieti Haapala Tapio Halkoaho Jussi S. Heinonen Henri Höytiä Jukka Konnunaho Ville Järvinen Some new insights into the geochronology of the Western Karelia Subprovince, Finnish Lapland Bulletin of the Geological Society of Finland geochronology u-pb zircon icp-ms eastern lapland archean finland 2.44 ga mafic layered intrusions |
| title | Some new insights into the geochronology of the Western Karelia Subprovince, Finnish Lapland |
| title_full | Some new insights into the geochronology of the Western Karelia Subprovince, Finnish Lapland |
| title_fullStr | Some new insights into the geochronology of the Western Karelia Subprovince, Finnish Lapland |
| title_full_unstemmed | Some new insights into the geochronology of the Western Karelia Subprovince, Finnish Lapland |
| title_short | Some new insights into the geochronology of the Western Karelia Subprovince, Finnish Lapland |
| title_sort | some new insights into the geochronology of the western karelia subprovince finnish lapland |
| topic | geochronology u-pb zircon icp-ms eastern lapland archean finland 2.44 ga mafic layered intrusions |
| url | https://www.geologinenseura.fi/sites/geologinenseura.fi/files/bulletin_vol92_1_5-17_2020_tepsell-etal.pdf |
| work_keys_str_mv | AT johannatepsell somenewinsightsintothegeochronologyofthewesternkareliasubprovincefinnishlapland AT otapaniramo somenewinsightsintothegeochronologyofthewesternkareliasubprovincefinnishlapland AT akuheinonen somenewinsightsintothegeochronologyofthewesternkareliasubprovincefinnishlapland AT yannlahaye somenewinsightsintothegeochronologyofthewesternkareliasubprovincefinnishlapland AT pietihaapala somenewinsightsintothegeochronologyofthewesternkareliasubprovincefinnishlapland AT tapiohalkoaho somenewinsightsintothegeochronologyofthewesternkareliasubprovincefinnishlapland AT jussisheinonen somenewinsightsintothegeochronologyofthewesternkareliasubprovincefinnishlapland AT henrihoytia somenewinsightsintothegeochronologyofthewesternkareliasubprovincefinnishlapland AT jukkakonnunaho somenewinsightsintothegeochronologyofthewesternkareliasubprovincefinnishlapland AT villejarvinen somenewinsightsintothegeochronologyofthewesternkareliasubprovincefinnishlapland |