气候变化领域集成服务门户(CCPortal): Driving mechanisms of organic carbon burial in the Early Cretaceous South Atlantic Cape Basin (DSDP Site 361)

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DOI	10.5194/cp-17-469-2021
	Driving mechanisms of organic carbon burial in the Early Cretaceous South Atlantic Cape Basin (DSDP Site 361)
	Dummann W.; Steinig S.; Hofmann P.; Lenz M.; Kusch S.; Flögel S.; Olaf Herrle J.; Hallmann C.; Rethemeyer J.; Uwe Kasper H.; Wagner T.
发表日期	2021
ISSN	1814-9324
起始页码	387
结束页码	407
卷号	17 期号:1
英文摘要	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 enhanced organic carbon burial in the deep Cape Basin. These results suggest that deep marine environments of emerging ocean basins responded sensitively and directly to short-term fluctuations in riverine nutrient fluxes.We explain this relationship using the lack of wide and mature continental shelf seas that could have acted as a barrier or filter for nutrient transfer from the continent into the deep ocean. © Author(s) 2021.
来源期刊	Climate of the Past
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/183603
作者单位	Institute of Geology and Mineralogy, University of Cologne, Cologne, 50674, Germany; Geomar Helmholtz Centre for Ocean Research Kiel, Kiel, 24148, Germany; Institute of Geosciences, Goethe University Frankfurt, Frankfurt am Main, 60438, Germany; Max Planck Institute for Biogeochemistry, Jena, 07745, Germany; Marum, University of Bremen, Bremen, 28359, Germany; Lyell Centre, School of Energy Geoscience Infrastructure and Society, Heriot-Watt University, Edinburgh, EH14 4AS, United Kingdom
推荐引用方式 GB/T 7714	Dummann W.,Steinig S.,Hofmann P.,et al. Driving mechanisms of organic carbon burial in the Early Cretaceous South Atlantic Cape Basin (DSDP Site 361)[J],2021,17(1).
APA	Dummann W..,Steinig S..,Hofmann P..,Lenz M..,Kusch S..,...&Wagner T..(2021).Driving mechanisms of organic carbon burial in the Early Cretaceous South Atlantic Cape Basin (DSDP Site 361).Climate of the Past,17(1).
MLA	Dummann W.,et al."Driving mechanisms of organic carbon burial in the Early Cretaceous South Atlantic Cape Basin (DSDP Site 361)".Climate of the Past 17.1(2021).