Controls on the formation of microbially induced sedimentary structures and biotic recovery in the Lower Triassic of Arctic Canada
Microbially-induced sedimentary structures (MISS) are reportedly widespread in the Early Triassic and their occurrence is attributed to either the extinction of marine grazers (allowing mat preservation) during the Permo-Triassic mass extinction or the suppression of grazing due to harsh, oxygen-poo...
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Geological Society of America
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Online Access: | https://hull-repository.worktribe.com/file/2114156/1/Early%20Triassic%20May%2019 https://hull-repository.worktribe.com/output/2114156 https://doi.org/10.1130/B35229.1 |
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ftunivhullir:oai:hull-repository.worktribe.com:2114156 2024-09-15T18:38:29+00:00 Controls on the formation of microbially induced sedimentary structures and biotic recovery in the Lower Triassic of Arctic Canada Bond, David P.G. Wignall, Paul Grasby, Stephen Pruss, Sara Peakall, Jeffrey 2019-08-30 https://hull-repository.worktribe.com/file/2114156/1/Early%20Triassic%20May%2019 https://hull-repository.worktribe.com/output/2114156 https://doi.org/10.1130/B35229.1 English eng Geological Society of America https://hull-repository.worktribe.com/output/2114156 Bulletin of the Geological Society of America Volume 132 Issue 5-6 Pagination 918-930 doi:https://doi.org/10.1130/B35229.1 https://hull-repository.worktribe.com/file/2114156/1/Early%20Triassic%20May%2019 0016-7606 doi:10.1130/B35229.1 openAccess Permo-Triassic Extinction Recovery Microbial mats Textured organic surfaces Journal Article acceptedVersion publishedVersion 2019 ftunivhullir https://doi.org/10.1130/B35229.1 2024-07-22T14:05:21Z Microbially-induced sedimentary structures (MISS) are reportedly widespread in the Early Triassic and their occurrence is attributed to either the extinction of marine grazers (allowing mat preservation) during the Permo-Triassic mass extinction or the suppression of grazing due to harsh, oxygen-poor conditions in its aftermath. Here we report on the abundant occurrence of MISS in the Lower Triassic Blind Fiord Formation of the Sverdrup Basin, Arctic Canada. Sedimentological analysis shows that mid-shelf settings were dominated by deposition from cohesive sand-mud flows that produced heterolithic, rippled sandstones facies that pass down dip into laminated siltstones and ultimately basinal mudrocks. The absence of storm beds and any other “event beds” points to an unusual climatic regime of humid, quiet conditions characterized by near continuous run off. Geochemical proxies for oxygenation (Mo/Al, Th/U and pyrite framboid analysis) indicate that lower dysoxic conditions prevailed in the Basin for much of the Early Triassic. The resultant lack of bioturbation allowed the development and preservation of MISS, including wrinkle structures and bubble textures. The microbial mats responsible for these structures are envisaged to have thrived, on sandy substrates, within the photic zone, in oxygen-poor conditions. The dysoxic history was punctuated by better-oxygenated phases, which coincide with the loss of MISS. Thus, Permo-Triassic boundary and Griesbachian mudrocks from the deepest-water settings have common benthos and a well-developed, tiered burrow profile dominated by Phycosiphon. The presence of the intense burrowing in the earliest Triassic contradicts the notion that bioturbation was severely suppressed at this time due to extinction losses at the end of the Permian. The notion that Early Triassic MISS preservation was caused by the extinction of mat grazers is not tenable. Article in Journal/Newspaper sverdrup basin University of Hull: Repository@Hull GSA Bulletin 132 5-6 918 930 |
institution |
Open Polar |
collection |
University of Hull: Repository@Hull |
op_collection_id |
ftunivhullir |
language |
English |
topic |
Permo-Triassic Extinction Recovery Microbial mats Textured organic surfaces |
spellingShingle |
Permo-Triassic Extinction Recovery Microbial mats Textured organic surfaces Bond, David P.G. Wignall, Paul Grasby, Stephen Pruss, Sara Peakall, Jeffrey Controls on the formation of microbially induced sedimentary structures and biotic recovery in the Lower Triassic of Arctic Canada |
topic_facet |
Permo-Triassic Extinction Recovery Microbial mats Textured organic surfaces |
description |
Microbially-induced sedimentary structures (MISS) are reportedly widespread in the Early Triassic and their occurrence is attributed to either the extinction of marine grazers (allowing mat preservation) during the Permo-Triassic mass extinction or the suppression of grazing due to harsh, oxygen-poor conditions in its aftermath. Here we report on the abundant occurrence of MISS in the Lower Triassic Blind Fiord Formation of the Sverdrup Basin, Arctic Canada. Sedimentological analysis shows that mid-shelf settings were dominated by deposition from cohesive sand-mud flows that produced heterolithic, rippled sandstones facies that pass down dip into laminated siltstones and ultimately basinal mudrocks. The absence of storm beds and any other “event beds” points to an unusual climatic regime of humid, quiet conditions characterized by near continuous run off. Geochemical proxies for oxygenation (Mo/Al, Th/U and pyrite framboid analysis) indicate that lower dysoxic conditions prevailed in the Basin for much of the Early Triassic. The resultant lack of bioturbation allowed the development and preservation of MISS, including wrinkle structures and bubble textures. The microbial mats responsible for these structures are envisaged to have thrived, on sandy substrates, within the photic zone, in oxygen-poor conditions. The dysoxic history was punctuated by better-oxygenated phases, which coincide with the loss of MISS. Thus, Permo-Triassic boundary and Griesbachian mudrocks from the deepest-water settings have common benthos and a well-developed, tiered burrow profile dominated by Phycosiphon. The presence of the intense burrowing in the earliest Triassic contradicts the notion that bioturbation was severely suppressed at this time due to extinction losses at the end of the Permian. The notion that Early Triassic MISS preservation was caused by the extinction of mat grazers is not tenable. |
format |
Article in Journal/Newspaper |
author |
Bond, David P.G. Wignall, Paul Grasby, Stephen Pruss, Sara Peakall, Jeffrey |
author_facet |
Bond, David P.G. Wignall, Paul Grasby, Stephen Pruss, Sara Peakall, Jeffrey |
author_sort |
Bond, David P.G. |
title |
Controls on the formation of microbially induced sedimentary structures and biotic recovery in the Lower Triassic of Arctic Canada |
title_short |
Controls on the formation of microbially induced sedimentary structures and biotic recovery in the Lower Triassic of Arctic Canada |
title_full |
Controls on the formation of microbially induced sedimentary structures and biotic recovery in the Lower Triassic of Arctic Canada |
title_fullStr |
Controls on the formation of microbially induced sedimentary structures and biotic recovery in the Lower Triassic of Arctic Canada |
title_full_unstemmed |
Controls on the formation of microbially induced sedimentary structures and biotic recovery in the Lower Triassic of Arctic Canada |
title_sort |
controls on the formation of microbially induced sedimentary structures and biotic recovery in the lower triassic of arctic canada |
publisher |
Geological Society of America |
publishDate |
2019 |
url |
https://hull-repository.worktribe.com/file/2114156/1/Early%20Triassic%20May%2019 https://hull-repository.worktribe.com/output/2114156 https://doi.org/10.1130/B35229.1 |
genre |
sverdrup basin |
genre_facet |
sverdrup basin |
op_relation |
https://hull-repository.worktribe.com/output/2114156 Bulletin of the Geological Society of America Volume 132 Issue 5-6 Pagination 918-930 doi:https://doi.org/10.1130/B35229.1 https://hull-repository.worktribe.com/file/2114156/1/Early%20Triassic%20May%2019 0016-7606 doi:10.1130/B35229.1 |
op_rights |
openAccess |
op_doi |
https://doi.org/10.1130/B35229.1 |
container_title |
GSA Bulletin |
container_volume |
132 |
container_issue |
5-6 |
container_start_page |
918 |
op_container_end_page |
930 |
_version_ |
1810482879660032000 |