Metasomatic Reactions between Archean Dunite and Trondhjemite at the Seqi Olivine Mine in Greenland
A metasomatic zone formed between the contact of a 2940 ± 5 Ma intrusive trondhjemite sheet in the Archean dunite of the Seqi Ultramafic Complex, SW Greenland, consists of three distinct mineral zones dominated by (1) talc, (2) anthophyllite, and (3) phlogopite. These zones supposedly resulted from...
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ftmdpi:oai:mdpi.com:/2075-163X/10/1/85/ 2023-08-20T04:06:51+02:00 Metasomatic Reactions between Archean Dunite and Trondhjemite at the Seqi Olivine Mine in Greenland Laura Whyatt Stefan Peters Andreas Pack Christopher L. Kirkland Tonci Balic-Zunic Kristoffer Szilas agris 2020-01-20 application/pdf https://doi.org/10.3390/min10010085 EN eng Multidisciplinary Digital Publishing Institute Mineral Deposits https://dx.doi.org/10.3390/min10010085 https://creativecommons.org/licenses/by/4.0/ Minerals; Volume 10; Issue 1; Pages: 85 Archaean Greenland ultramafic rocks metasomatism talc anthophyllite phlogopite Text 2020 ftmdpi https://doi.org/10.3390/min10010085 2023-07-31T23:01:26Z A metasomatic zone formed between the contact of a 2940 ± 5 Ma intrusive trondhjemite sheet in the Archean dunite of the Seqi Ultramafic Complex, SW Greenland, consists of three distinct mineral zones dominated by (1) talc, (2) anthophyllite, and (3) phlogopite. These zones supposedly resulted from a process of dissolution of olivine by silica rich fluid residual from the trondhjemite magma, with crystallization of secondary minerals along a compositional gradient in the fluid phase. A zircon crystal inclusion in a large (4 cm) olivine porphyroblast was dated in situ via LA-ICP-MS U–Pb isotope analysis, yielding a weighted mean 207Pb/206Pb age of 2963 ± 1 Ma, which coincides with granulite facies metamorphism and potential dehydration. Considering phase relations appropriate for the dunite composition, we deduced the talc forming conditions to be at temperatures of 600–650 °C and at a pressure below 1 GPa. This is supported by oxygen isotope data for talc, anthophyllite and phlogopite in the metasomatic zone, which suggests formation in the temperature range of 600–700 °C from fluids that had a δ18O of ~8‰ and a Δ’17O0.528 of about −40 ppm, i.e., from fluids that could have been derived from the late stage trondhjemite sheet. Text Greenland MDPI Open Access Publishing Greenland Minerals 10 1 85 |
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MDPI Open Access Publishing |
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ftmdpi |
language |
English |
topic |
Archaean Greenland ultramafic rocks metasomatism talc anthophyllite phlogopite |
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Archaean Greenland ultramafic rocks metasomatism talc anthophyllite phlogopite Laura Whyatt Stefan Peters Andreas Pack Christopher L. Kirkland Tonci Balic-Zunic Kristoffer Szilas Metasomatic Reactions between Archean Dunite and Trondhjemite at the Seqi Olivine Mine in Greenland |
topic_facet |
Archaean Greenland ultramafic rocks metasomatism talc anthophyllite phlogopite |
description |
A metasomatic zone formed between the contact of a 2940 ± 5 Ma intrusive trondhjemite sheet in the Archean dunite of the Seqi Ultramafic Complex, SW Greenland, consists of three distinct mineral zones dominated by (1) talc, (2) anthophyllite, and (3) phlogopite. These zones supposedly resulted from a process of dissolution of olivine by silica rich fluid residual from the trondhjemite magma, with crystallization of secondary minerals along a compositional gradient in the fluid phase. A zircon crystal inclusion in a large (4 cm) olivine porphyroblast was dated in situ via LA-ICP-MS U–Pb isotope analysis, yielding a weighted mean 207Pb/206Pb age of 2963 ± 1 Ma, which coincides with granulite facies metamorphism and potential dehydration. Considering phase relations appropriate for the dunite composition, we deduced the talc forming conditions to be at temperatures of 600–650 °C and at a pressure below 1 GPa. This is supported by oxygen isotope data for talc, anthophyllite and phlogopite in the metasomatic zone, which suggests formation in the temperature range of 600–700 °C from fluids that had a δ18O of ~8‰ and a Δ’17O0.528 of about −40 ppm, i.e., from fluids that could have been derived from the late stage trondhjemite sheet. |
format |
Text |
author |
Laura Whyatt Stefan Peters Andreas Pack Christopher L. Kirkland Tonci Balic-Zunic Kristoffer Szilas |
author_facet |
Laura Whyatt Stefan Peters Andreas Pack Christopher L. Kirkland Tonci Balic-Zunic Kristoffer Szilas |
author_sort |
Laura Whyatt |
title |
Metasomatic Reactions between Archean Dunite and Trondhjemite at the Seqi Olivine Mine in Greenland |
title_short |
Metasomatic Reactions between Archean Dunite and Trondhjemite at the Seqi Olivine Mine in Greenland |
title_full |
Metasomatic Reactions between Archean Dunite and Trondhjemite at the Seqi Olivine Mine in Greenland |
title_fullStr |
Metasomatic Reactions between Archean Dunite and Trondhjemite at the Seqi Olivine Mine in Greenland |
title_full_unstemmed |
Metasomatic Reactions between Archean Dunite and Trondhjemite at the Seqi Olivine Mine in Greenland |
title_sort |
metasomatic reactions between archean dunite and trondhjemite at the seqi olivine mine in greenland |
publisher |
Multidisciplinary Digital Publishing Institute |
publishDate |
2020 |
url |
https://doi.org/10.3390/min10010085 |
op_coverage |
agris |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Greenland |
genre_facet |
Greenland |
op_source |
Minerals; Volume 10; Issue 1; Pages: 85 |
op_relation |
Mineral Deposits https://dx.doi.org/10.3390/min10010085 |
op_rights |
https://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.3390/min10010085 |
container_title |
Minerals |
container_volume |
10 |
container_issue |
1 |
container_start_page |
85 |
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1774718188703973376 |