Driving mechanisms of organic carbon burial in the Early Cretaceous South Atlantic Cape Basin (DSDP Site 361)
Extensive black shale deposits formed in the Early Cretaceous South Atlantic, supporting the notion that this emerging ocean basin was a globally important site of organic carbon burial. The magnitude of organic carbon burial in marine basins is known to be controlled by various tectonic, oceanograp...
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ftdoajarticles:oai:doaj.org/article:e0eb3fc706164db1b8a22244046782c4 2023-05-15T18:25:53+02:00 Driving mechanisms of organic carbon burial in the Early Cretaceous South Atlantic Cape Basin (DSDP Site 361) W. Dummann S. Steinig P. Hofmann M. Lenz S. Kusch S. Flögel J. O. Herrle C. Hallmann J. Rethemeyer H. U. Kasper T. Wagner 2021-02-01T00:00:00Z https://doi.org/10.5194/cp-17-469-2021 https://doaj.org/article/e0eb3fc706164db1b8a22244046782c4 EN eng Copernicus Publications https://cp.copernicus.org/articles/17/469/2021/cp-17-469-2021.pdf https://doaj.org/toc/1814-9324 https://doaj.org/toc/1814-9332 doi:10.5194/cp-17-469-2021 1814-9324 1814-9332 https://doaj.org/article/e0eb3fc706164db1b8a22244046782c4 Climate of the Past, Vol 17, Pp 469-490 (2021) Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 article 2021 ftdoajarticles https://doi.org/10.5194/cp-17-469-2021 2022-12-31T09:44:30Z Extensive black shale deposits formed in the Early Cretaceous South Atlantic, supporting the notion that this emerging ocean basin was a globally important site of organic carbon burial. The magnitude of organic carbon burial in marine basins is known to be controlled by various tectonic, oceanographic, hydrological, and climatic processes acting on different temporal and spatial scales, the nature and relative importance of which are poorly understood for the young South Atlantic. Here we present new bulk and molecular geochemical data from an Aptian–Albian sediment record recovered from the deep Cape Basin at Deep Sea Drilling Project (DSDP) Site 361, which we combine with general circulation model results to identify driving mechanisms of organic carbon burial. A multimillion-year decrease (i.e., Early Aptian–Albian) in organic carbon burial, reflected in a lithological succession of black shale, gray shale, and red beds, was caused by increasing bottom water oxygenation due to abating hydrographic restriction via South Atlantic–Southern Ocean gateways. These results emphasize basin evolution and ocean gateway development as a decisive primary control on enhanced organic carbon preservation in the Cape Basin at geological timescales ( > 1 Myr). The Early Aptian black shale sequence comprises alternations of shales with high ( > 6 %) and relatively low ( ∼ 3.5 %) organic carbon content of marine sources, the former being deposited during the global Oceanic Anoxic Event (OAE) 1a, as well as during repetitive intervals before and after OAE 1a. In all cases, these short-term intervals of enhanced organic carbon burial coincided with strong influxes of sediments derived from the proximal African continent, indicating closely coupled climate–land–ocean interactions. Supported by our model results, we show that fluctuations in weathering-derived nutrient input from the southern African continent, linked to changes in orbitally driven humidity and aridity, were the underlying drivers of repetitive episodes of ... Article in Journal/Newspaper Southern Ocean Directory of Open Access Journals: DOAJ Articles Southern Ocean Climate of the Past 17 1 469 490 |
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topic |
Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 |
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Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 W. Dummann S. Steinig P. Hofmann M. Lenz S. Kusch S. Flögel J. O. Herrle C. Hallmann J. Rethemeyer H. U. Kasper T. Wagner Driving mechanisms of organic carbon burial in the Early Cretaceous South Atlantic Cape Basin (DSDP Site 361) |
topic_facet |
Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 |
description |
Extensive black shale deposits formed in the Early Cretaceous South Atlantic, supporting the notion that this emerging ocean basin was a globally important site of organic carbon burial. The magnitude of organic carbon burial in marine basins is known to be controlled by various tectonic, oceanographic, hydrological, and climatic processes acting on different temporal and spatial scales, the nature and relative importance of which are poorly understood for the young South Atlantic. Here we present new bulk and molecular geochemical data from an Aptian–Albian sediment record recovered from the deep Cape Basin at Deep Sea Drilling Project (DSDP) Site 361, which we combine with general circulation model results to identify driving mechanisms of organic carbon burial. A multimillion-year decrease (i.e., Early Aptian–Albian) in organic carbon burial, reflected in a lithological succession of black shale, gray shale, and red beds, was caused by increasing bottom water oxygenation due to abating hydrographic restriction via South Atlantic–Southern Ocean gateways. These results emphasize basin evolution and ocean gateway development as a decisive primary control on enhanced organic carbon preservation in the Cape Basin at geological timescales ( > 1 Myr). The Early Aptian black shale sequence comprises alternations of shales with high ( > 6 %) and relatively low ( ∼ 3.5 %) organic carbon content of marine sources, the former being deposited during the global Oceanic Anoxic Event (OAE) 1a, as well as during repetitive intervals before and after OAE 1a. In all cases, these short-term intervals of enhanced organic carbon burial coincided with strong influxes of sediments derived from the proximal African continent, indicating closely coupled climate–land–ocean interactions. Supported by our model results, we show that fluctuations in weathering-derived nutrient input from the southern African continent, linked to changes in orbitally driven humidity and aridity, were the underlying drivers of repetitive episodes of ... |
format |
Article in Journal/Newspaper |
author |
W. Dummann S. Steinig P. Hofmann M. Lenz S. Kusch S. Flögel J. O. Herrle C. Hallmann J. Rethemeyer H. U. Kasper T. Wagner |
author_facet |
W. Dummann S. Steinig P. Hofmann M. Lenz S. Kusch S. Flögel J. O. Herrle C. Hallmann J. Rethemeyer H. U. Kasper T. Wagner |
author_sort |
W. Dummann |
title |
Driving mechanisms of organic carbon burial in the Early Cretaceous South Atlantic Cape Basin (DSDP Site 361) |
title_short |
Driving mechanisms of organic carbon burial in the Early Cretaceous South Atlantic Cape Basin (DSDP Site 361) |
title_full |
Driving mechanisms of organic carbon burial in the Early Cretaceous South Atlantic Cape Basin (DSDP Site 361) |
title_fullStr |
Driving mechanisms of organic carbon burial in the Early Cretaceous South Atlantic Cape Basin (DSDP Site 361) |
title_full_unstemmed |
Driving mechanisms of organic carbon burial in the Early Cretaceous South Atlantic Cape Basin (DSDP Site 361) |
title_sort |
driving mechanisms of organic carbon burial in the early cretaceous south atlantic cape basin (dsdp site 361) |
publisher |
Copernicus Publications |
publishDate |
2021 |
url |
https://doi.org/10.5194/cp-17-469-2021 https://doaj.org/article/e0eb3fc706164db1b8a22244046782c4 |
geographic |
Southern Ocean |
geographic_facet |
Southern Ocean |
genre |
Southern Ocean |
genre_facet |
Southern Ocean |
op_source |
Climate of the Past, Vol 17, Pp 469-490 (2021) |
op_relation |
https://cp.copernicus.org/articles/17/469/2021/cp-17-469-2021.pdf https://doaj.org/toc/1814-9324 https://doaj.org/toc/1814-9332 doi:10.5194/cp-17-469-2021 1814-9324 1814-9332 https://doaj.org/article/e0eb3fc706164db1b8a22244046782c4 |
op_doi |
https://doi.org/10.5194/cp-17-469-2021 |
container_title |
Climate of the Past |
container_volume |
17 |
container_issue |
1 |
container_start_page |
469 |
op_container_end_page |
490 |
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1766207599928147968 |