Late Cretaceous and Early Paleogene Fluid Circulation and Microbial Activity in Deep Fracture Networks of the Precambrian Basement of Western Greenland
Deep fracture-hosted fluids of Precambrian bedrock cratons are relatively stagnant over long time spans compared to near-surface systems. However, episodic events, such as fracture reactivations, transgressions, and deglaciations, may introduce dilute water, replacing, and mixing with the deep conti...
Published in: | Geochemistry, Geophysics, Geosystems |
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Language: | English |
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Linnéuniversitetet, Institutionen för biologi och miljö (BOM)
2024
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Online Access: | http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-132532 https://doi.org/10.1029/2024gc011646 |
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ftlinnaeusuniv:oai:DiVA.org:lnu-132532 2024-09-30T14:35:47+00:00 Late Cretaceous and Early Paleogene Fluid Circulation and Microbial Activity in Deep Fracture Networks of the Precambrian Basement of Western Greenland Drake, Henrik Makahnouk, W. R. M. Roberts, N. M. W. Reinhardt, M. Henkemans, E. Frape, S. K. Tullborg, E.â€L. Broman, C. Whitehouse, M. J. Kooijman, E. 2024 application/pdf http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-132532 https://doi.org/10.1029/2024gc011646 eng eng Linnéuniversitetet, Institutionen för biologi och miljö (BOM) University of Waterloo, Canada British Geological Survey, UK University of Göttingen, Germany University of Waterloo, Canada;WSP Canada Inc., Canada Terralogica AB, Sweden Stockholm University, Sweden Swedish Museum of Natural History, Sweden Geochemistry Geophysics Geosystems, 2024, 25:9, orcid:0000-0001-7230-6509 orcid:0009-0005-6867-1059 orcid:0000-0001-8272-5432 orcid:0000-0003-0606-9175 http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-132532 doi:10.1029/2024gc011646 info:eu-repo/semantics/openAccess Geology Geologi Geochemistry Geokemi Environmental Sciences Miljövetenskap Article in journal info:eu-repo/semantics/article text 2024 ftlinnaeusuniv https://doi.org/10.1029/2024gc011646 2024-09-17T23:57:39Z Deep fracture-hosted fluids of Precambrian bedrock cratons are relatively stagnant over long time spans compared to near-surface systems. However, episodic events, such as fracture reactivations, transgressions, and deglaciations, may introduce dilute water, replacing, and mixing with the deep continental brines, thereby sparking microbial activity. Secondary minerals that line bedrock fractures serve as important geochemical archives for such episodic events. Here we explore the fracture mineral record of Archean rocks of Western Greenland by analyzing samples from deep boreholes with the aim to trace and characterize episodic paleofluid flow and paleomicrobial activity. A sequence of hydrothermal to low temperature fluid flow events is demonstrated. For the youngest generation, microscale S-isotope analysis of pyrite reveals substantial 34S-depletion (minimum δ34S:−58‰V-CDT) compared to fracture-hosted barite (δ34S:13‰ ± 2‰) and gypsum (δ34S:2.6‰–10.6‰). This suggests the formation of pyrite following S isotope fractionation during microbial sulfate reduction. This metabolism is further indicated by several methyl-branched fatty acids preserved in calcite. A general discrepancy between calcite and groundwater δ18O-values suggests that calcite formed from water different from the presently residing glacial meltwater-influenced groundwater mix. High spatial resolution U-Pb carbonate geochronology of the youngest generation of calcite yielded ages for two samples: 64 ± 3, 75 ± 7 Ma (2σ). These ages overlap with tectonic events related to early stages, or prestages, of the opening of the Atlantic and Labrador Seas. This suggests that deep fracture networks in Western Greenland were colonized by microorganisms, such as sulfate reducers, in the course of this extensional event. Article in Journal/Newspaper Greenland Linnaeus University Kalmar Växjö: Publications (DiVA) Greenland Geochemistry, Geophysics, Geosystems 25 9 |
institution |
Open Polar |
collection |
Linnaeus University Kalmar Växjö: Publications (DiVA) |
op_collection_id |
ftlinnaeusuniv |
language |
English |
topic |
Geology Geologi Geochemistry Geokemi Environmental Sciences Miljövetenskap |
spellingShingle |
Geology Geologi Geochemistry Geokemi Environmental Sciences Miljövetenskap Drake, Henrik Makahnouk, W. R. M. Roberts, N. M. W. Reinhardt, M. Henkemans, E. Frape, S. K. Tullborg, E.â€L. Broman, C. Whitehouse, M. J. Kooijman, E. Late Cretaceous and Early Paleogene Fluid Circulation and Microbial Activity in Deep Fracture Networks of the Precambrian Basement of Western Greenland |
topic_facet |
Geology Geologi Geochemistry Geokemi Environmental Sciences Miljövetenskap |
description |
Deep fracture-hosted fluids of Precambrian bedrock cratons are relatively stagnant over long time spans compared to near-surface systems. However, episodic events, such as fracture reactivations, transgressions, and deglaciations, may introduce dilute water, replacing, and mixing with the deep continental brines, thereby sparking microbial activity. Secondary minerals that line bedrock fractures serve as important geochemical archives for such episodic events. Here we explore the fracture mineral record of Archean rocks of Western Greenland by analyzing samples from deep boreholes with the aim to trace and characterize episodic paleofluid flow and paleomicrobial activity. A sequence of hydrothermal to low temperature fluid flow events is demonstrated. For the youngest generation, microscale S-isotope analysis of pyrite reveals substantial 34S-depletion (minimum δ34S:−58‰V-CDT) compared to fracture-hosted barite (δ34S:13‰ ± 2‰) and gypsum (δ34S:2.6‰–10.6‰). This suggests the formation of pyrite following S isotope fractionation during microbial sulfate reduction. This metabolism is further indicated by several methyl-branched fatty acids preserved in calcite. A general discrepancy between calcite and groundwater δ18O-values suggests that calcite formed from water different from the presently residing glacial meltwater-influenced groundwater mix. High spatial resolution U-Pb carbonate geochronology of the youngest generation of calcite yielded ages for two samples: 64 ± 3, 75 ± 7 Ma (2σ). These ages overlap with tectonic events related to early stages, or prestages, of the opening of the Atlantic and Labrador Seas. This suggests that deep fracture networks in Western Greenland were colonized by microorganisms, such as sulfate reducers, in the course of this extensional event. |
format |
Article in Journal/Newspaper |
author |
Drake, Henrik Makahnouk, W. R. M. Roberts, N. M. W. Reinhardt, M. Henkemans, E. Frape, S. K. Tullborg, E.â€L. Broman, C. Whitehouse, M. J. Kooijman, E. |
author_facet |
Drake, Henrik Makahnouk, W. R. M. Roberts, N. M. W. Reinhardt, M. Henkemans, E. Frape, S. K. Tullborg, E.â€L. Broman, C. Whitehouse, M. J. Kooijman, E. |
author_sort |
Drake, Henrik |
title |
Late Cretaceous and Early Paleogene Fluid Circulation and Microbial Activity in Deep Fracture Networks of the Precambrian Basement of Western Greenland |
title_short |
Late Cretaceous and Early Paleogene Fluid Circulation and Microbial Activity in Deep Fracture Networks of the Precambrian Basement of Western Greenland |
title_full |
Late Cretaceous and Early Paleogene Fluid Circulation and Microbial Activity in Deep Fracture Networks of the Precambrian Basement of Western Greenland |
title_fullStr |
Late Cretaceous and Early Paleogene Fluid Circulation and Microbial Activity in Deep Fracture Networks of the Precambrian Basement of Western Greenland |
title_full_unstemmed |
Late Cretaceous and Early Paleogene Fluid Circulation and Microbial Activity in Deep Fracture Networks of the Precambrian Basement of Western Greenland |
title_sort |
late cretaceous and early paleogene fluid circulation and microbial activity in deep fracture networks of the precambrian basement of western greenland |
publisher |
Linnéuniversitetet, Institutionen för biologi och miljö (BOM) |
publishDate |
2024 |
url |
http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-132532 https://doi.org/10.1029/2024gc011646 |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Greenland |
genre_facet |
Greenland |
op_relation |
Geochemistry Geophysics Geosystems, 2024, 25:9, orcid:0000-0001-7230-6509 orcid:0009-0005-6867-1059 orcid:0000-0001-8272-5432 orcid:0000-0003-0606-9175 http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-132532 doi:10.1029/2024gc011646 |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1029/2024gc011646 |
container_title |
Geochemistry, Geophysics, Geosystems |
container_volume |
25 |
container_issue |
9 |
_version_ |
1811639035263713280 |