Paleoceanography of the Late Cretaceous northwestern Tethys Ocean: Seasonal upwelling or steady thermocline?
In this study we attempted to assess whether seasonal upwelling or a steady thermocline persisted at the western margin of the Tethys Ocean during the late Turonian–early Coniacian interval. For this scope, we employed novel and published stable oxygen isotope (δ(18)O) data of various organisms (biv...
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ftpubmed:oai:pubmedcentral.nih.gov:7451568 2023-05-15T17:35:47+02:00 Paleoceanography of the Late Cretaceous northwestern Tethys Ocean: Seasonal upwelling or steady thermocline? Walliser, Eric Otto Schöne, Bernd R. 2020-08-27 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7451568/ http://www.ncbi.nlm.nih.gov/pubmed/32853273 https://doi.org/10.1371/journal.pone.0238040 en eng Public Library of Science http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7451568/ http://www.ncbi.nlm.nih.gov/pubmed/32853273 http://dx.doi.org/10.1371/journal.pone.0238040 © 2020 Walliser, Schöne http://creativecommons.org/licenses/by/4.0/ This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. CC-BY PLoS One Research Article Text 2020 ftpubmed https://doi.org/10.1371/journal.pone.0238040 2020-09-06T00:41:57Z In this study we attempted to assess whether seasonal upwelling or a steady thermocline persisted at the western margin of the Tethys Ocean during the late Turonian–early Coniacian interval. For this scope, we employed novel and published stable oxygen isotope (δ(18)O) data of various organisms (bivalves, bivalves, brachiopods, fish and belemnites). New seasonally resolved temperature estimates were based on the δ(18)O record of sequentially sampled inoceramid (Inoceramus sp.) and rudist (Hippurites resectus) shells from the Scaglia Rossa and Gosau deposits of northern Italy and western Austria, respectively. Diagenetic screening was performed using reflected light, cathodoluminescence (CL), scanning electron microscopy (SEM) and stable isotope analysis. Originally preserved δ(13)C and δ(18)O values were used to characterize the lifestyle of the bivalves and detect vital effects that could have biased oxygen isotope-based temperature reconstructions. Inoceramid δ(18)O values provide–for the first time–information on temperatures of Tethyan benthic waters, which were, on average, 14.4 ± 0.6 °C and fluctuated seasonally within a range of less than 2 °C. Such a thermal regime is in line with the temperatures postulated for late Turonian boreal water masses and support the existence of a cold water supply from the North Atlantic to the Tethyan bottom. Bottom cooling, however, did not affect the shallow water environment. In fact, the rudist-based temperature estimates for shallow water environment revealed a mean annual range of 11 °C, between 24 and 35 °C (assuming a seasonally constant δ18O(w) = 1.0 ‰), which are among the warmest temperatures recorded over the entire Late Cretaceous. Our findings, thus, suggest a strong thermal and food web decoupling between the two environments. The absence of a seasonal vertical homogenization of different water bodies suggests the existence of a steady thermocline and, therefore, contrasts with the presence of an active coastal upwelling in the region as hypothesized by ... Text North Atlantic PubMed Central (PMC) Rossa ENVELOPE(-65.233,-65.233,-65.960,-65.960) PLOS ONE 15 8 e0238040 |
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English |
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Research Article |
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Research Article Walliser, Eric Otto Schöne, Bernd R. Paleoceanography of the Late Cretaceous northwestern Tethys Ocean: Seasonal upwelling or steady thermocline? |
topic_facet |
Research Article |
description |
In this study we attempted to assess whether seasonal upwelling or a steady thermocline persisted at the western margin of the Tethys Ocean during the late Turonian–early Coniacian interval. For this scope, we employed novel and published stable oxygen isotope (δ(18)O) data of various organisms (bivalves, bivalves, brachiopods, fish and belemnites). New seasonally resolved temperature estimates were based on the δ(18)O record of sequentially sampled inoceramid (Inoceramus sp.) and rudist (Hippurites resectus) shells from the Scaglia Rossa and Gosau deposits of northern Italy and western Austria, respectively. Diagenetic screening was performed using reflected light, cathodoluminescence (CL), scanning electron microscopy (SEM) and stable isotope analysis. Originally preserved δ(13)C and δ(18)O values were used to characterize the lifestyle of the bivalves and detect vital effects that could have biased oxygen isotope-based temperature reconstructions. Inoceramid δ(18)O values provide–for the first time–information on temperatures of Tethyan benthic waters, which were, on average, 14.4 ± 0.6 °C and fluctuated seasonally within a range of less than 2 °C. Such a thermal regime is in line with the temperatures postulated for late Turonian boreal water masses and support the existence of a cold water supply from the North Atlantic to the Tethyan bottom. Bottom cooling, however, did not affect the shallow water environment. In fact, the rudist-based temperature estimates for shallow water environment revealed a mean annual range of 11 °C, between 24 and 35 °C (assuming a seasonally constant δ18O(w) = 1.0 ‰), which are among the warmest temperatures recorded over the entire Late Cretaceous. Our findings, thus, suggest a strong thermal and food web decoupling between the two environments. The absence of a seasonal vertical homogenization of different water bodies suggests the existence of a steady thermocline and, therefore, contrasts with the presence of an active coastal upwelling in the region as hypothesized by ... |
format |
Text |
author |
Walliser, Eric Otto Schöne, Bernd R. |
author_facet |
Walliser, Eric Otto Schöne, Bernd R. |
author_sort |
Walliser, Eric Otto |
title |
Paleoceanography of the Late Cretaceous northwestern Tethys Ocean: Seasonal upwelling or steady thermocline? |
title_short |
Paleoceanography of the Late Cretaceous northwestern Tethys Ocean: Seasonal upwelling or steady thermocline? |
title_full |
Paleoceanography of the Late Cretaceous northwestern Tethys Ocean: Seasonal upwelling or steady thermocline? |
title_fullStr |
Paleoceanography of the Late Cretaceous northwestern Tethys Ocean: Seasonal upwelling or steady thermocline? |
title_full_unstemmed |
Paleoceanography of the Late Cretaceous northwestern Tethys Ocean: Seasonal upwelling or steady thermocline? |
title_sort |
paleoceanography of the late cretaceous northwestern tethys ocean: seasonal upwelling or steady thermocline? |
publisher |
Public Library of Science |
publishDate |
2020 |
url |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7451568/ http://www.ncbi.nlm.nih.gov/pubmed/32853273 https://doi.org/10.1371/journal.pone.0238040 |
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ENVELOPE(-65.233,-65.233,-65.960,-65.960) |
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Rossa |
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North Atlantic |
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North Atlantic |
op_source |
PLoS One |
op_relation |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7451568/ http://www.ncbi.nlm.nih.gov/pubmed/32853273 http://dx.doi.org/10.1371/journal.pone.0238040 |
op_rights |
© 2020 Walliser, Schöne http://creativecommons.org/licenses/by/4.0/ This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. |
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CC-BY |
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https://doi.org/10.1371/journal.pone.0238040 |
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