In situ geochemical characterization of pyrite crystals in burial dolomites of St. George Group carbonates
SIMS was used to measure the δ34S of pyrite disseminated in burial dolomite matrix of St. George Group at three localities in western Newfoundland. At Main Brook, δ34S values for the pyrite grains show wide variation (-15 to +20 ‰ (n = 20), but are mostly negative. Combined with a paucity of two-pha...
Main Authors: | , |
---|---|
Format: | Article in Journal/Newspaper |
Language: | unknown |
Published: |
NRC Research Press (a division of Canadian Science Publishing)
2017
|
Subjects: | |
Online Access: | http://hdl.handle.net/1807/87213 http://www.nrcresearchpress.com/doi/abs/10.1139/cjes-2016-0152 |
id |
ftunivtoronto:oai:localhost:1807/87213 |
---|---|
record_format |
openpolar |
spelling |
ftunivtoronto:oai:localhost:1807/87213 2023-05-15T17:22:52+02:00 In situ geochemical characterization of pyrite crystals in burial dolomites of St. George Group carbonates Olanipekun, Babatunde John Azmy, Karem 2017-11-02 http://hdl.handle.net/1807/87213 http://www.nrcresearchpress.com/doi/abs/10.1139/cjes-2016-0152 unknown NRC Research Press (a division of Canadian Science Publishing) 0008-4077 http://hdl.handle.net/1807/87213 http://www.nrcresearchpress.com/doi/abs/10.1139/cjes-2016-0152 Article 2017 ftunivtoronto 2020-06-17T12:16:35Z SIMS was used to measure the δ34S of pyrite disseminated in burial dolomite matrix of St. George Group at three localities in western Newfoundland. At Main Brook, δ34S values for the pyrite grains show wide variation (-15 to +20 ‰ (n = 20), but are mostly negative. Combined with a paucity of two-phase fluid inclusions in the host burial dolomite, the depleted δ34S values suggest that the pyrite is a by-product of BSR. Predominantly negative δ34S values was also obtained for sampled pyrite at Daniel’s Harbour and Port au Choix, however relatively high homogenization temperatures (>100oC) of two-phase fluid inclusions in the host dolomites is incompatible with a BSR process for pyrite formation. More so, Daniel’s Harbour is a site for main stage sulfide mineralization (MVT system), hosted in similarly burial dolomite and that has been previously constrained to be associated with TSR. A relative proximity of the currently studied pyrite samples to this MVT system deposit is thus inconsistent with an in-situ BSR for these pyrites. The analyzed pyrite grains are encased in bitumen, post-date burial dolomite and pre-date late stage saddle dolomite. Thus, the depleted δ34S signature was likely inherited from migrated hydrocarbons in the reservoir. Incursion of an initial pulse of hot sulfate-rich brine into the formation can cause thermal cracking of hydrocarbons, thereby releasing its low δ34S. Subsequently, the main stage sulfide mineralization (Mississippi Valley Type deposit) occurred via in-situ TSR. These findings have implication for the paragenetic history of sulfide minerals precipitated during MVT-type mineralization. The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author. Article in Journal/Newspaper Newfoundland Port au Choix University of Toronto: Research Repository T-Space Main Brook ENVELOPE(-56.782,-56.782,49.533,49.533) Port au Choix ENVELOPE(-57.365,-57.365,50.717,50.717) |
institution |
Open Polar |
collection |
University of Toronto: Research Repository T-Space |
op_collection_id |
ftunivtoronto |
language |
unknown |
description |
SIMS was used to measure the δ34S of pyrite disseminated in burial dolomite matrix of St. George Group at three localities in western Newfoundland. At Main Brook, δ34S values for the pyrite grains show wide variation (-15 to +20 ‰ (n = 20), but are mostly negative. Combined with a paucity of two-phase fluid inclusions in the host burial dolomite, the depleted δ34S values suggest that the pyrite is a by-product of BSR. Predominantly negative δ34S values was also obtained for sampled pyrite at Daniel’s Harbour and Port au Choix, however relatively high homogenization temperatures (>100oC) of two-phase fluid inclusions in the host dolomites is incompatible with a BSR process for pyrite formation. More so, Daniel’s Harbour is a site for main stage sulfide mineralization (MVT system), hosted in similarly burial dolomite and that has been previously constrained to be associated with TSR. A relative proximity of the currently studied pyrite samples to this MVT system deposit is thus inconsistent with an in-situ BSR for these pyrites. The analyzed pyrite grains are encased in bitumen, post-date burial dolomite and pre-date late stage saddle dolomite. Thus, the depleted δ34S signature was likely inherited from migrated hydrocarbons in the reservoir. Incursion of an initial pulse of hot sulfate-rich brine into the formation can cause thermal cracking of hydrocarbons, thereby releasing its low δ34S. Subsequently, the main stage sulfide mineralization (Mississippi Valley Type deposit) occurred via in-situ TSR. These findings have implication for the paragenetic history of sulfide minerals precipitated during MVT-type mineralization. The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author. |
format |
Article in Journal/Newspaper |
author |
Olanipekun, Babatunde John Azmy, Karem |
spellingShingle |
Olanipekun, Babatunde John Azmy, Karem In situ geochemical characterization of pyrite crystals in burial dolomites of St. George Group carbonates |
author_facet |
Olanipekun, Babatunde John Azmy, Karem |
author_sort |
Olanipekun, Babatunde John |
title |
In situ geochemical characterization of pyrite crystals in burial dolomites of St. George Group carbonates |
title_short |
In situ geochemical characterization of pyrite crystals in burial dolomites of St. George Group carbonates |
title_full |
In situ geochemical characterization of pyrite crystals in burial dolomites of St. George Group carbonates |
title_fullStr |
In situ geochemical characterization of pyrite crystals in burial dolomites of St. George Group carbonates |
title_full_unstemmed |
In situ geochemical characterization of pyrite crystals in burial dolomites of St. George Group carbonates |
title_sort |
in situ geochemical characterization of pyrite crystals in burial dolomites of st. george group carbonates |
publisher |
NRC Research Press (a division of Canadian Science Publishing) |
publishDate |
2017 |
url |
http://hdl.handle.net/1807/87213 http://www.nrcresearchpress.com/doi/abs/10.1139/cjes-2016-0152 |
long_lat |
ENVELOPE(-56.782,-56.782,49.533,49.533) ENVELOPE(-57.365,-57.365,50.717,50.717) |
geographic |
Main Brook Port au Choix |
geographic_facet |
Main Brook Port au Choix |
genre |
Newfoundland Port au Choix |
genre_facet |
Newfoundland Port au Choix |
op_relation |
0008-4077 http://hdl.handle.net/1807/87213 http://www.nrcresearchpress.com/doi/abs/10.1139/cjes-2016-0152 |
_version_ |
1766109756618964992 |