Progressive 18 O depletion during CO 2 separation from a carbon dioxide-rich hydrothermal fluid: evidence from the Grey River tungsten deposit, Newfoundland
Oxygen isotope data for the Grey River tungsten prospect, Newfoundland, Canada, indicate a progressive depletion in δ 18 O fluid during mineralization. Early veins with pegmatitic affinities were deposited at 470 °C and pressures greater than 1 kbar (100 MPa), from a fluid with a δ 18 O composition...
Published in: | Canadian Journal of Earth Sciences |
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Canadian Science Publishing
1982
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crcansciencepubl:10.1139/e82-198 2023-12-17T10:44:46+01:00 Progressive 18 O depletion during CO 2 separation from a carbon dioxide-rich hydrothermal fluid: evidence from the Grey River tungsten deposit, Newfoundland Higgins, N. C. Kerrich, R. 1982 http://dx.doi.org/10.1139/e82-198 http://www.nrcresearchpress.com/doi/pdf/10.1139/e82-198 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Earth Sciences volume 19, issue 12, page 2247-2257 ISSN 0008-4077 1480-3313 General Earth and Planetary Sciences journal-article 1982 crcansciencepubl https://doi.org/10.1139/e82-198 2023-11-19T13:38:33Z Oxygen isotope data for the Grey River tungsten prospect, Newfoundland, Canada, indicate a progressive depletion in δ 18 O fluid during mineralization. Early veins with pegmatitic affinities were deposited at 470 °C and pressures greater than 1 kbar (100 MPa), from a fluid with a δ 18 O composition of 7.4‰, presumed to be of magmatic origin. Successive vein deposition, at progressively lower temperatures and pressures, culminated in the precipitation of wolframite-bearing veins at a temperature of 300 °C and pressures of 150–320 bar (15–32 MPa), from a low salinity fluid with a δ 18 O composition in the range 3.2–1.6‰.Low values of δ 18 O (and δD fluid ) are recorded in many vein tungsten deposits and are normally interpreted as reflecting mixing of isotopically light meteoric fluids or formation brines with magmatic fluids. However, fluid-inclusion evidence for the Grey River mineralization indicates that a 40 mol% CO 2 loss occurred by immiscibility and retrograde boiling of the hydrothermal fluid between 420 and 300 °C. Such a chemical change would have significantly altered the oxygen isotopic character of the hydrothermal fluid since CO 2 fractionates 18 O relative to coexisting water by ~10‰ at 400 °C and ~14‰ at 300 °C. Calculations using available CO 2 –H 2 O fractionation factors reveal that up to a 7‰ depletion in δ 18 O of the residual aqueous fluids may occur as a result of the 40 mol% CO 2 loss from the hydrothermal fluid. Article in Journal/Newspaper Newfoundland Canadian Science Publishing (via Crossref) Canada Canadian Journal of Earth Sciences 19 12 2247 2257 |
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Open Polar |
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Canadian Science Publishing (via Crossref) |
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crcansciencepubl |
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English |
topic |
General Earth and Planetary Sciences |
spellingShingle |
General Earth and Planetary Sciences Higgins, N. C. Kerrich, R. Progressive 18 O depletion during CO 2 separation from a carbon dioxide-rich hydrothermal fluid: evidence from the Grey River tungsten deposit, Newfoundland |
topic_facet |
General Earth and Planetary Sciences |
description |
Oxygen isotope data for the Grey River tungsten prospect, Newfoundland, Canada, indicate a progressive depletion in δ 18 O fluid during mineralization. Early veins with pegmatitic affinities were deposited at 470 °C and pressures greater than 1 kbar (100 MPa), from a fluid with a δ 18 O composition of 7.4‰, presumed to be of magmatic origin. Successive vein deposition, at progressively lower temperatures and pressures, culminated in the precipitation of wolframite-bearing veins at a temperature of 300 °C and pressures of 150–320 bar (15–32 MPa), from a low salinity fluid with a δ 18 O composition in the range 3.2–1.6‰.Low values of δ 18 O (and δD fluid ) are recorded in many vein tungsten deposits and are normally interpreted as reflecting mixing of isotopically light meteoric fluids or formation brines with magmatic fluids. However, fluid-inclusion evidence for the Grey River mineralization indicates that a 40 mol% CO 2 loss occurred by immiscibility and retrograde boiling of the hydrothermal fluid between 420 and 300 °C. Such a chemical change would have significantly altered the oxygen isotopic character of the hydrothermal fluid since CO 2 fractionates 18 O relative to coexisting water by ~10‰ at 400 °C and ~14‰ at 300 °C. Calculations using available CO 2 –H 2 O fractionation factors reveal that up to a 7‰ depletion in δ 18 O of the residual aqueous fluids may occur as a result of the 40 mol% CO 2 loss from the hydrothermal fluid. |
format |
Article in Journal/Newspaper |
author |
Higgins, N. C. Kerrich, R. |
author_facet |
Higgins, N. C. Kerrich, R. |
author_sort |
Higgins, N. C. |
title |
Progressive 18 O depletion during CO 2 separation from a carbon dioxide-rich hydrothermal fluid: evidence from the Grey River tungsten deposit, Newfoundland |
title_short |
Progressive 18 O depletion during CO 2 separation from a carbon dioxide-rich hydrothermal fluid: evidence from the Grey River tungsten deposit, Newfoundland |
title_full |
Progressive 18 O depletion during CO 2 separation from a carbon dioxide-rich hydrothermal fluid: evidence from the Grey River tungsten deposit, Newfoundland |
title_fullStr |
Progressive 18 O depletion during CO 2 separation from a carbon dioxide-rich hydrothermal fluid: evidence from the Grey River tungsten deposit, Newfoundland |
title_full_unstemmed |
Progressive 18 O depletion during CO 2 separation from a carbon dioxide-rich hydrothermal fluid: evidence from the Grey River tungsten deposit, Newfoundland |
title_sort |
progressive 18 o depletion during co 2 separation from a carbon dioxide-rich hydrothermal fluid: evidence from the grey river tungsten deposit, newfoundland |
publisher |
Canadian Science Publishing |
publishDate |
1982 |
url |
http://dx.doi.org/10.1139/e82-198 http://www.nrcresearchpress.com/doi/pdf/10.1139/e82-198 |
geographic |
Canada |
geographic_facet |
Canada |
genre |
Newfoundland |
genre_facet |
Newfoundland |
op_source |
Canadian Journal of Earth Sciences volume 19, issue 12, page 2247-2257 ISSN 0008-4077 1480-3313 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/e82-198 |
container_title |
Canadian Journal of Earth Sciences |
container_volume |
19 |
container_issue |
12 |
container_start_page |
2247 |
op_container_end_page |
2257 |
_version_ |
1785563768483217408 |