THE EARLY TOARCIAN (JURASSIC) ANOXIC EVENT - STRATIGRAPHIC, SEDIMENTARY, AND GEOCHEMICAL EVIDENCE

Detailed paleogeographic studies in the Southern Alps suggest that an oxygen-minimum model is appropriate for interpreting conditions on Tethyan continental margins. Advection of manganese in this low-oxygen layer may explain the local occurrence of carbonate ores of this element. Carbon-sulfur and...

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Main Author: Jenkyns, H
Format: Journal article
Language:English
Published: 1988
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author Jenkyns, H
author_facet Jenkyns, H
author_sort Jenkyns, H
collection OXFORD
description Detailed paleogeographic studies in the Southern Alps suggest that an oxygen-minimum model is appropriate for interpreting conditions on Tethyan continental margins. Advection of manganese in this low-oxygen layer may explain the local occurrence of carbonate ores of this element. Carbon-sulfur and iron-sulfur ratios, although showing considerable scatter, suggest that bottom waters at this time were locally euxinic, containing free hydrogen sulfide. This Oceanic Anoxic Event was preceded by significant faunal turnover of ammonites in Tethys and accompanied by widespread extinction of benthos in northern Europe in response to the lateral spread of anoxic bottom waters during transgression. Similar changes may be recognized in other parts of the world. Other anoxic events may have taken place during the Jurassic, but documentation is as yet meagre. Furthermore, models for such phenomena remain largely speculative, although upwelling and increased planktonic productivity, commencing in pre-Toarcian time, are favored for the falciferum-Zone event documented here.-from Author
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spelling oxford-uuid:58a7cc03-0eaa-4f54-a96b-c05dcb2b11852022-03-26T17:04:52ZTHE EARLY TOARCIAN (JURASSIC) ANOXIC EVENT - STRATIGRAPHIC, SEDIMENTARY, AND GEOCHEMICAL EVIDENCEJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:58a7cc03-0eaa-4f54-a96b-c05dcb2b1185EnglishSymplectic Elements at Oxford1988Jenkyns, HDetailed paleogeographic studies in the Southern Alps suggest that an oxygen-minimum model is appropriate for interpreting conditions on Tethyan continental margins. Advection of manganese in this low-oxygen layer may explain the local occurrence of carbonate ores of this element. Carbon-sulfur and iron-sulfur ratios, although showing considerable scatter, suggest that bottom waters at this time were locally euxinic, containing free hydrogen sulfide. This Oceanic Anoxic Event was preceded by significant faunal turnover of ammonites in Tethys and accompanied by widespread extinction of benthos in northern Europe in response to the lateral spread of anoxic bottom waters during transgression. Similar changes may be recognized in other parts of the world. Other anoxic events may have taken place during the Jurassic, but documentation is as yet meagre. Furthermore, models for such phenomena remain largely speculative, although upwelling and increased planktonic productivity, commencing in pre-Toarcian time, are favored for the falciferum-Zone event documented here.-from Author
spellingShingle Jenkyns, H
THE EARLY TOARCIAN (JURASSIC) ANOXIC EVENT - STRATIGRAPHIC, SEDIMENTARY, AND GEOCHEMICAL EVIDENCE
title THE EARLY TOARCIAN (JURASSIC) ANOXIC EVENT - STRATIGRAPHIC, SEDIMENTARY, AND GEOCHEMICAL EVIDENCE
title_full THE EARLY TOARCIAN (JURASSIC) ANOXIC EVENT - STRATIGRAPHIC, SEDIMENTARY, AND GEOCHEMICAL EVIDENCE
title_fullStr THE EARLY TOARCIAN (JURASSIC) ANOXIC EVENT - STRATIGRAPHIC, SEDIMENTARY, AND GEOCHEMICAL EVIDENCE
title_full_unstemmed THE EARLY TOARCIAN (JURASSIC) ANOXIC EVENT - STRATIGRAPHIC, SEDIMENTARY, AND GEOCHEMICAL EVIDENCE
title_short THE EARLY TOARCIAN (JURASSIC) ANOXIC EVENT - STRATIGRAPHIC, SEDIMENTARY, AND GEOCHEMICAL EVIDENCE
title_sort early toarcian jurassic anoxic event stratigraphic sedimentary and geochemical evidence
work_keys_str_mv AT jenkynsh theearlytoarcianjurassicanoxiceventstratigraphicsedimentaryandgeochemicalevidence
AT jenkynsh earlytoarcianjurassicanoxiceventstratigraphicsedimentaryandgeochemicalevidence