Dégradation et lessivage des hydrocarbures de la formation ordovicienne de Thumb Mountain encaissant le gîte Zn–Pb de Polaris (Territoires du Nord-Ouest, Canada)
Carbonate rocks of the Ordovician Thumb Mountain Formation, host to the Zn–Pb Polaris deposit, contain hydrocarbons that show types of alteration classically attributed to biodegradation and water washing. The hydrocarbons of the upper part of this formation and of the overlying Irene Bay Formation...
Published in: | Canadian Journal of Earth Sciences |
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crcansciencepubl:10.1139/e95-084 2023-12-17T10:32:32+01:00 Dégradation et lessivage des hydrocarbures de la formation ordovicienne de Thumb Mountain encaissant le gîte Zn–Pb de Polaris (Territoires du Nord-Ouest, Canada) Disnar, J.R. Héroux, Y. 1995 http://dx.doi.org/10.1139/e95-084 http://www.nrcresearchpress.com/doi/pdf/10.1139/e95-084 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Earth Sciences volume 32, issue 7, page 1017-1034 ISSN 0008-4077 1480-3313 General Earth and Planetary Sciences journal-article 1995 crcansciencepubl https://doi.org/10.1139/e95-084 2023-11-19T13:39:23Z Carbonate rocks of the Ordovician Thumb Mountain Formation, host to the Zn–Pb Polaris deposit, contain hydrocarbons that show types of alteration classically attributed to biodegradation and water washing. The hydrocarbons of the upper part of this formation and of the overlying Irene Bay Formation indicate alterations due to water washing only. The hydrocarbons of the impermeable shales of the overlying Cape Phillips Formation display indices of only higher thermal maturity than the underlying units. Contrary to classical concepts of hydrocarbon biodegradation, n-alkanes, cyclohexylalkanes, even isoprenoids and perhaps also steranes seem to have been degraded simultaneously and not successively in this sequence. This alteration process is mainly responsible for a log-linear decrease of the amounts of n-alkanes and cyclohexylalkanes with increasing depth. The severe and uniform alteration of aromatic hydrocarbons throughout the interval, which is opposite to the progressive alteration of associated n-alkanes, can be attributed solely to water washing. This conclusion necessitates a reconsideration of previous interpretations attributing the loss of short-side chain substituted polyaromatic compounds to microbial activity. Hopanes, tri-and tetra–cyclic terpanes as well as aromatic steroids and hopanoids seem to have been unaffected by the alteration phenomena. The increase in the degree of alteration of the hydrocarbons with increasing depth implies that the responsible migrating fluid circulated per ascensum. Article in Journal/Newspaper Irene Bay Territoires du Nord-Ouest Canadian Science Publishing (via Crossref) Canada Thumb ENVELOPE(-64.259,-64.259,-65.247,-65.247) Cape Phillips ENVELOPE(-62.600,-62.600,-84.750,-84.750) Irene Bay ENVELOPE(-81.781,-81.781,79.002,79.002) Thumb Mountain ENVELOPE(-81.465,-81.465,79.035,79.035) Canadian Journal of Earth Sciences 32 7 1017 1034 |
institution |
Open Polar |
collection |
Canadian Science Publishing (via Crossref) |
op_collection_id |
crcansciencepubl |
language |
English |
topic |
General Earth and Planetary Sciences |
spellingShingle |
General Earth and Planetary Sciences Disnar, J.R. Héroux, Y. Dégradation et lessivage des hydrocarbures de la formation ordovicienne de Thumb Mountain encaissant le gîte Zn–Pb de Polaris (Territoires du Nord-Ouest, Canada) |
topic_facet |
General Earth and Planetary Sciences |
description |
Carbonate rocks of the Ordovician Thumb Mountain Formation, host to the Zn–Pb Polaris deposit, contain hydrocarbons that show types of alteration classically attributed to biodegradation and water washing. The hydrocarbons of the upper part of this formation and of the overlying Irene Bay Formation indicate alterations due to water washing only. The hydrocarbons of the impermeable shales of the overlying Cape Phillips Formation display indices of only higher thermal maturity than the underlying units. Contrary to classical concepts of hydrocarbon biodegradation, n-alkanes, cyclohexylalkanes, even isoprenoids and perhaps also steranes seem to have been degraded simultaneously and not successively in this sequence. This alteration process is mainly responsible for a log-linear decrease of the amounts of n-alkanes and cyclohexylalkanes with increasing depth. The severe and uniform alteration of aromatic hydrocarbons throughout the interval, which is opposite to the progressive alteration of associated n-alkanes, can be attributed solely to water washing. This conclusion necessitates a reconsideration of previous interpretations attributing the loss of short-side chain substituted polyaromatic compounds to microbial activity. Hopanes, tri-and tetra–cyclic terpanes as well as aromatic steroids and hopanoids seem to have been unaffected by the alteration phenomena. The increase in the degree of alteration of the hydrocarbons with increasing depth implies that the responsible migrating fluid circulated per ascensum. |
format |
Article in Journal/Newspaper |
author |
Disnar, J.R. Héroux, Y. |
author_facet |
Disnar, J.R. Héroux, Y. |
author_sort |
Disnar, J.R. |
title |
Dégradation et lessivage des hydrocarbures de la formation ordovicienne de Thumb Mountain encaissant le gîte Zn–Pb de Polaris (Territoires du Nord-Ouest, Canada) |
title_short |
Dégradation et lessivage des hydrocarbures de la formation ordovicienne de Thumb Mountain encaissant le gîte Zn–Pb de Polaris (Territoires du Nord-Ouest, Canada) |
title_full |
Dégradation et lessivage des hydrocarbures de la formation ordovicienne de Thumb Mountain encaissant le gîte Zn–Pb de Polaris (Territoires du Nord-Ouest, Canada) |
title_fullStr |
Dégradation et lessivage des hydrocarbures de la formation ordovicienne de Thumb Mountain encaissant le gîte Zn–Pb de Polaris (Territoires du Nord-Ouest, Canada) |
title_full_unstemmed |
Dégradation et lessivage des hydrocarbures de la formation ordovicienne de Thumb Mountain encaissant le gîte Zn–Pb de Polaris (Territoires du Nord-Ouest, Canada) |
title_sort |
dégradation et lessivage des hydrocarbures de la formation ordovicienne de thumb mountain encaissant le gîte zn–pb de polaris (territoires du nord-ouest, canada) |
publisher |
Canadian Science Publishing |
publishDate |
1995 |
url |
http://dx.doi.org/10.1139/e95-084 http://www.nrcresearchpress.com/doi/pdf/10.1139/e95-084 |
long_lat |
ENVELOPE(-64.259,-64.259,-65.247,-65.247) ENVELOPE(-62.600,-62.600,-84.750,-84.750) ENVELOPE(-81.781,-81.781,79.002,79.002) ENVELOPE(-81.465,-81.465,79.035,79.035) |
geographic |
Canada Thumb Cape Phillips Irene Bay Thumb Mountain |
geographic_facet |
Canada Thumb Cape Phillips Irene Bay Thumb Mountain |
genre |
Irene Bay Territoires du Nord-Ouest |
genre_facet |
Irene Bay Territoires du Nord-Ouest |
op_source |
Canadian Journal of Earth Sciences volume 32, issue 7, page 1017-1034 ISSN 0008-4077 1480-3313 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/e95-084 |
container_title |
Canadian Journal of Earth Sciences |
container_volume |
32 |
container_issue |
7 |
container_start_page |
1017 |
op_container_end_page |
1034 |
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1785586315493900288 |