Geochemistry of post-tectonic mafic intrusions in the Central Gneiss Terrane of southwestern Newfoundland
South of Grand Lake, mafic igneous complexes of proven or probable Silurian age intruded quartzofeldspathic gneisses that had been deformed and raised to granulite fades in mid-Ordovician time. The mafic igneous complexes consist of gabbroic units, which locally exhibit igneous layering and contain...
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Atlantic Geoscience Society
1989
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ftuninewbrunojs:oai:ojs.journals.lib.unb.ca:article/1682 2023-05-15T17:22:43+02:00 Geochemistry of post-tectonic mafic intrusions in the Central Gneiss Terrane of southwestern Newfoundland Currie, K. L. van Berkel, J. T. 1989-12-01 application/pdf https://journals.lib.unb.ca/index.php/ag/article/view/1682 eng eng Atlantic Geoscience Society https://journals.lib.unb.ca/index.php/ag/article/view/1682/2048 https://journals.lib.unb.ca/index.php/ag/article/view/1682 Copyright (c) 2015 Atlantic Geology Atlantic Geoscience; Vol. 25 No. 3 (1989) 2564-2987 info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion research-article 1989 ftuninewbrunojs 2022-07-11T11:41:30Z South of Grand Lake, mafic igneous complexes of proven or probable Silurian age intruded quartzofeldspathic gneisses that had been deformed and raised to granulite fades in mid-Ordovician time. The mafic igneous complexes consist of gabbroic units, which locally exhibit igneous layering and contain ultramafic cumulate pods, that grade to and are cut by finer-grained hornblende gabbro. Compositions more felsic than diorite exhibit intrusive to co-mingling relationships with more mafic rocks. Chemical data for possible liquid-derived rocks exhibit characteristics suggesting derivation from diverse mantle sources, followed by varying combinations of fractionation, contamination, mixing and metasomatism by hydrous fluids during ascent and emplacement. The post-tectonic emplacement of the plutons suggests stabilisation of die Central Gneiss Terrane by late Ordovician or Silurian time, when the adjacent terrane to the southeast (Meelpaeg Terrane) was still undergoing deformation and granitic plutonism. RÉSUMÉ Au sud de Grand Lake, des complexes ignés mafiques, dont l’âge est assurément ou probablement silurien, firent intrusion dans desgneiss quartzofeldspathiques qui avaient été déforrnés avaient atteint le faciès des granulites au milieude l’Ordovicien. Les complexes ignés mafiques sont constitues d'unités gabbroiques (montrant localement un aspect rubanné et contenant des lentilles de cumulate ultramaflques) passant graduellement à un gabbro à hornblende moins grenu qui les recoupe aussi. Les compositions plus felsiques que la diorite sont en relation d'intrusion ou de mélange avec les roches plus mafiques. Les données chimiques concernant des roches possiblement derives du liquide montrent des caractéres suggèrant une dérivation à partir de diverses sources mantelliques, suivie d'une combinaison variée de ... Article in Journal/Newspaper Newfoundland University of New Brunswick: Centre for Digital Scholarship Journals Atlantic Geology 25 3 |
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English |
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South of Grand Lake, mafic igneous complexes of proven or probable Silurian age intruded quartzofeldspathic gneisses that had been deformed and raised to granulite fades in mid-Ordovician time. The mafic igneous complexes consist of gabbroic units, which locally exhibit igneous layering and contain ultramafic cumulate pods, that grade to and are cut by finer-grained hornblende gabbro. Compositions more felsic than diorite exhibit intrusive to co-mingling relationships with more mafic rocks. Chemical data for possible liquid-derived rocks exhibit characteristics suggesting derivation from diverse mantle sources, followed by varying combinations of fractionation, contamination, mixing and metasomatism by hydrous fluids during ascent and emplacement. The post-tectonic emplacement of the plutons suggests stabilisation of die Central Gneiss Terrane by late Ordovician or Silurian time, when the adjacent terrane to the southeast (Meelpaeg Terrane) was still undergoing deformation and granitic plutonism. RÉSUMÉ Au sud de Grand Lake, des complexes ignés mafiques, dont l’âge est assurément ou probablement silurien, firent intrusion dans desgneiss quartzofeldspathiques qui avaient été déforrnés avaient atteint le faciès des granulites au milieude l’Ordovicien. Les complexes ignés mafiques sont constitues d'unités gabbroiques (montrant localement un aspect rubanné et contenant des lentilles de cumulate ultramaflques) passant graduellement à un gabbro à hornblende moins grenu qui les recoupe aussi. Les compositions plus felsiques que la diorite sont en relation d'intrusion ou de mélange avec les roches plus mafiques. Les données chimiques concernant des roches possiblement derives du liquide montrent des caractéres suggèrant une dérivation à partir de diverses sources mantelliques, suivie d'une combinaison variée de ... |
format |
Article in Journal/Newspaper |
author |
Currie, K. L. van Berkel, J. T. |
spellingShingle |
Currie, K. L. van Berkel, J. T. Geochemistry of post-tectonic mafic intrusions in the Central Gneiss Terrane of southwestern Newfoundland |
author_facet |
Currie, K. L. van Berkel, J. T. |
author_sort |
Currie, K. L. |
title |
Geochemistry of post-tectonic mafic intrusions in the Central Gneiss Terrane of southwestern Newfoundland |
title_short |
Geochemistry of post-tectonic mafic intrusions in the Central Gneiss Terrane of southwestern Newfoundland |
title_full |
Geochemistry of post-tectonic mafic intrusions in the Central Gneiss Terrane of southwestern Newfoundland |
title_fullStr |
Geochemistry of post-tectonic mafic intrusions in the Central Gneiss Terrane of southwestern Newfoundland |
title_full_unstemmed |
Geochemistry of post-tectonic mafic intrusions in the Central Gneiss Terrane of southwestern Newfoundland |
title_sort |
geochemistry of post-tectonic mafic intrusions in the central gneiss terrane of southwestern newfoundland |
publisher |
Atlantic Geoscience Society |
publishDate |
1989 |
url |
https://journals.lib.unb.ca/index.php/ag/article/view/1682 |
genre |
Newfoundland |
genre_facet |
Newfoundland |
op_source |
Atlantic Geoscience; Vol. 25 No. 3 (1989) 2564-2987 |
op_relation |
https://journals.lib.unb.ca/index.php/ag/article/view/1682/2048 https://journals.lib.unb.ca/index.php/ag/article/view/1682 |
op_rights |
Copyright (c) 2015 Atlantic Geology |
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Atlantic Geology |
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