Paleoenvironmental changes across the Mid Cenomanian Event in the tropical Atlantic Ocean (Demerara Rise, ODP Leg 207) inferred from benthic foraminiferal assemblages
This study is based on Cenomanian sediments of Ocean Drilling Program (ODP) Sites 1258 and 1260 from Demerara Rise (Leg 207, western tropical Atlantic, off Suriname, ~1000 and ~500 m paleo-water depth, respectively). Studied sediments consist of laminated black shales with TOC values between 3 and 1...
Published in: | Marine Micropaleontology |
---|---|
Main Authors: | , , , , |
Format: | Article in Journal/Newspaper |
Language: | unknown |
Published: |
2009
|
Subjects: | |
Online Access: | https://eprints.soton.ac.uk/65029/ |
id |
ftsouthampton:oai:eprints.soton.ac.uk:65029 |
---|---|
record_format |
openpolar |
spelling |
ftsouthampton:oai:eprints.soton.ac.uk:65029 2024-02-11T10:06:44+01:00 Paleoenvironmental changes across the Mid Cenomanian Event in the tropical Atlantic Ocean (Demerara Rise, ODP Leg 207) inferred from benthic foraminiferal assemblages Friedrich, Oliver Erbacher, Jochen Wilson, Paul A. Moriya, Kazuyoshi Mutterlose, Jörg 2009-04 https://eprints.soton.ac.uk/65029/ unknown Friedrich, Oliver, Erbacher, Jochen, Wilson, Paul A., Moriya, Kazuyoshi and Mutterlose, Jörg (2009) Paleoenvironmental changes across the Mid Cenomanian Event in the tropical Atlantic Ocean (Demerara Rise, ODP Leg 207) inferred from benthic foraminiferal assemblages. Marine Micropaleontology, 71 (1-2), 28-40. (doi:10.1016/j.marmicro.2009.01.002 <http://dx.doi.org/10.1016/j.marmicro.2009.01.002>). Article PeerReviewed 2009 ftsouthampton https://doi.org/10.1016/j.marmicro.2009.01.002 2024-01-25T23:18:55Z This study is based on Cenomanian sediments of Ocean Drilling Program (ODP) Sites 1258 and 1260 from Demerara Rise (Leg 207, western tropical Atlantic, off Suriname, ~1000 and ~500 m paleo-water depth, respectively). Studied sediments consist of laminated black shales with TOC values between 3 and 18 % and include the Mid Cenomanian Event (MCE), a positive carbon isotope excursion predating the well-known Oceanic Anoxic Event 2 (OAE 2). Benthic foraminiferal assemblages of the continuously eutrophic environment at Demerara Rise are characterized by low diversities (? 9 species per sample) and large fluctuations in abundances, indicating oxygen depletion and varying organic matter fluxes. Dominant species at both sites are Bolivina anambra, Gabonita levis, Gavelinella dakotensis, Neobulimina albertensis, Praebulimina prolixa, and Tappanina cf. laciniosa. Benthic foraminiferal assemblages across the MCE show a threefold pattern: (1) stable ecological conditions below the MCE interval indicated by relatively high oxygenation and fluctuating organic matter flux, (2) decreasing oxygenation and/or higher organic matter flux during the MCE with decreasing benthic foraminiferal numbers and diversities (Site 1258) and a dominance of opportunistic species (Site 1260), and (3) anoxic to slightly dysoxic bottom-water conditions above the MCE as indicated by very low diversities and abundances or even the absence of benthic foraminifera. Slightly dysoxic conditions prevailed until OAE 2 at Demerara Rise. A comparison with other Atlantic Ocean and Tethyan sections indicates that the MCE reflects a paleoceanographic turning point towards lower bottom-water oxygenation, at least in the proto-North Atlantic Ocean and in the Tethyan and Boreal Realms. This general trend towards lower oxygenation of bottom waters across the MCE is accompanied by ongoing climate warming in combination with rising sea-level and the development of vast shallow epicontinental seas during the Middle and Late Cenomanian. These changes are proposed to ... Article in Journal/Newspaper North Atlantic University of Southampton: e-Prints Soton Marine Micropaleontology 71 1-2 28 40 |
institution |
Open Polar |
collection |
University of Southampton: e-Prints Soton |
op_collection_id |
ftsouthampton |
language |
unknown |
description |
This study is based on Cenomanian sediments of Ocean Drilling Program (ODP) Sites 1258 and 1260 from Demerara Rise (Leg 207, western tropical Atlantic, off Suriname, ~1000 and ~500 m paleo-water depth, respectively). Studied sediments consist of laminated black shales with TOC values between 3 and 18 % and include the Mid Cenomanian Event (MCE), a positive carbon isotope excursion predating the well-known Oceanic Anoxic Event 2 (OAE 2). Benthic foraminiferal assemblages of the continuously eutrophic environment at Demerara Rise are characterized by low diversities (? 9 species per sample) and large fluctuations in abundances, indicating oxygen depletion and varying organic matter fluxes. Dominant species at both sites are Bolivina anambra, Gabonita levis, Gavelinella dakotensis, Neobulimina albertensis, Praebulimina prolixa, and Tappanina cf. laciniosa. Benthic foraminiferal assemblages across the MCE show a threefold pattern: (1) stable ecological conditions below the MCE interval indicated by relatively high oxygenation and fluctuating organic matter flux, (2) decreasing oxygenation and/or higher organic matter flux during the MCE with decreasing benthic foraminiferal numbers and diversities (Site 1258) and a dominance of opportunistic species (Site 1260), and (3) anoxic to slightly dysoxic bottom-water conditions above the MCE as indicated by very low diversities and abundances or even the absence of benthic foraminifera. Slightly dysoxic conditions prevailed until OAE 2 at Demerara Rise. A comparison with other Atlantic Ocean and Tethyan sections indicates that the MCE reflects a paleoceanographic turning point towards lower bottom-water oxygenation, at least in the proto-North Atlantic Ocean and in the Tethyan and Boreal Realms. This general trend towards lower oxygenation of bottom waters across the MCE is accompanied by ongoing climate warming in combination with rising sea-level and the development of vast shallow epicontinental seas during the Middle and Late Cenomanian. These changes are proposed to ... |
format |
Article in Journal/Newspaper |
author |
Friedrich, Oliver Erbacher, Jochen Wilson, Paul A. Moriya, Kazuyoshi Mutterlose, Jörg |
spellingShingle |
Friedrich, Oliver Erbacher, Jochen Wilson, Paul A. Moriya, Kazuyoshi Mutterlose, Jörg Paleoenvironmental changes across the Mid Cenomanian Event in the tropical Atlantic Ocean (Demerara Rise, ODP Leg 207) inferred from benthic foraminiferal assemblages |
author_facet |
Friedrich, Oliver Erbacher, Jochen Wilson, Paul A. Moriya, Kazuyoshi Mutterlose, Jörg |
author_sort |
Friedrich, Oliver |
title |
Paleoenvironmental changes across the Mid Cenomanian Event in the tropical Atlantic Ocean (Demerara Rise, ODP Leg 207) inferred from benthic foraminiferal assemblages |
title_short |
Paleoenvironmental changes across the Mid Cenomanian Event in the tropical Atlantic Ocean (Demerara Rise, ODP Leg 207) inferred from benthic foraminiferal assemblages |
title_full |
Paleoenvironmental changes across the Mid Cenomanian Event in the tropical Atlantic Ocean (Demerara Rise, ODP Leg 207) inferred from benthic foraminiferal assemblages |
title_fullStr |
Paleoenvironmental changes across the Mid Cenomanian Event in the tropical Atlantic Ocean (Demerara Rise, ODP Leg 207) inferred from benthic foraminiferal assemblages |
title_full_unstemmed |
Paleoenvironmental changes across the Mid Cenomanian Event in the tropical Atlantic Ocean (Demerara Rise, ODP Leg 207) inferred from benthic foraminiferal assemblages |
title_sort |
paleoenvironmental changes across the mid cenomanian event in the tropical atlantic ocean (demerara rise, odp leg 207) inferred from benthic foraminiferal assemblages |
publishDate |
2009 |
url |
https://eprints.soton.ac.uk/65029/ |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_relation |
Friedrich, Oliver, Erbacher, Jochen, Wilson, Paul A., Moriya, Kazuyoshi and Mutterlose, Jörg (2009) Paleoenvironmental changes across the Mid Cenomanian Event in the tropical Atlantic Ocean (Demerara Rise, ODP Leg 207) inferred from benthic foraminiferal assemblages. Marine Micropaleontology, 71 (1-2), 28-40. (doi:10.1016/j.marmicro.2009.01.002 <http://dx.doi.org/10.1016/j.marmicro.2009.01.002>). |
op_doi |
https://doi.org/10.1016/j.marmicro.2009.01.002 |
container_title |
Marine Micropaleontology |
container_volume |
71 |
container_issue |
1-2 |
container_start_page |
28 |
op_container_end_page |
40 |
_version_ |
1790604633791528960 |