CaCO3, organic carbon and mass accumulation rates at DSDP Site 75-532, supplement to: Gardner, James V; Dean, Walter E; Wilson, Christine R (1984): Carbonate and organic-carbon cycles and the history of upwelling at Deep Sea Drilling Project Site 532, Walvis Ridge, South Atlantic Ocean. In: Hay, WW; Sibuet, J-C; et al. (eds.), Initial Reports of the Deep Sea Drilling Project (U.S. Govt. Printing Office), 75, 905-921
Detailed carbonate and organic-carbon stratigraphies were constructed from samples collected every 20 cm in a 250-m hydraulic piston core recovered at DSDP Site 532 on Walvis Ridge. This sampling interval represents about one sample every 5000 yr., based on sediment accumulation rates calculated fro...
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1984
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ftdatacite:10.1594/pangaea.810144 2023-05-15T17:41:47+02:00 CaCO3, organic carbon and mass accumulation rates at DSDP Site 75-532, supplement to: Gardner, James V; Dean, Walter E; Wilson, Christine R (1984): Carbonate and organic-carbon cycles and the history of upwelling at Deep Sea Drilling Project Site 532, Walvis Ridge, South Atlantic Ocean. In: Hay, WW; Sibuet, J-C; et al. (eds.), Initial Reports of the Deep Sea Drilling Project (U.S. Govt. Printing Office), 75, 905-921 Gardner, James V Dean, Walter E Wilson, Christine R 1984 application/zip https://dx.doi.org/10.1594/pangaea.810144 https://doi.pangaea.de/10.1594/PANGAEA.810144 en eng PANGAEA - Data Publisher for Earth & Environmental Science https://dx.doi.org/10.2973/dsdp.proc.75.126.1984 Creative Commons Attribution 3.0 Unported https://creativecommons.org/licenses/by/3.0/legalcode cc-by-3.0 CC-BY Drilling/drill rig Leg75 Glomar Challenger Deep Sea Drilling Project DSDP Collection article Supplementary Collection of Datasets 1984 ftdatacite https://doi.org/10.1594/pangaea.810144 https://doi.org/10.2973/dsdp.proc.75.126.1984 2021-11-05T12:55:41Z Detailed carbonate and organic-carbon stratigraphies were constructed from samples collected every 20 cm in a 250-m hydraulic piston core recovered at DSDP Site 532 on Walvis Ridge. This sampling interval represents about one sample every 5000 yr., based on sediment accumulation rates calculated from nannofossil biostratigraphic zones. All samples were analyzed for percent CaCO3, resulting in a detailed carbonate stratigraphy for the past 5.0 m.y. The samples for the top 110 m of section were also analyzed for organic carbon in order to construct a detailed organiccarbon stratigraphy for the last 2.5 m.y. The recovered section has distinct dark-light color cycles with average periodicities of 55, 58, and 30 k.y. for the Quaternary, upper Pliocene, and lower Pliocene, respectively. Periodicities of carbonate cycles are similar to the color cycles; most carbonate minima correspond to the dark parts of color cycles. The average periodicity for carbonate cycles is about 36 k.y. Darker parts of color cycles usually contain higher concentrations of organic carbon, but the organic- carbon record does not follow the cyclicity of the color cycles in detail, at least for the last 2.5 m.y. Organic-carbon cycles have an average periodicity of about 34 k.y. for the Quaternary and upper Pliocene. The cycles of CaCO3 and color have periodicities similar to those reported from carbonate stratigraphies from the northeast Atlantic, Caribbean, and eastern equatorial Pacific. The carbonate cycles at Site 532 are the result of external forcing, probably related to global climate, that affected fluctuations in both sediment supply from the African continental margin and productivity of siliceous organisms. The organic-carbon cycles have similar periodicities and similar changes in periodicities to those of the CaCO3 cycles. Semiquantitative estimates of diatom abundance from smear slides and concentrations of biogenic SiO2 calculated from chemical analyses suggest that upwelling at Site 532 was minor until about 3 m.y. ago. The Benguela-Current upwelling system either began at that time or, more likely, migrated into the area of Site 532, where it prevailed until some time between about 1.2 and 0.5 m.y. ago. The increase and decline of upwelling in the area of Site 532, however, did not disturb the trend of cyclicities of carbonate and organic carbon. The latest change in conditions at Site 532 was an increase in intensity of bottom currents during the past 0.5 m.y. that winnowed nannofossils, diatoms, and clay and left a lag deposit represented by a foraminifer-rich fades. Article in Journal/Newspaper Northeast Atlantic South Atlantic Ocean DataCite Metadata Store (German National Library of Science and Technology) Gardner ENVELOPE(65.903,65.903,-70.411,-70.411) Pacific |
institution |
Open Polar |
collection |
DataCite Metadata Store (German National Library of Science and Technology) |
op_collection_id |
ftdatacite |
language |
English |
topic |
Drilling/drill rig Leg75 Glomar Challenger Deep Sea Drilling Project DSDP |
spellingShingle |
Drilling/drill rig Leg75 Glomar Challenger Deep Sea Drilling Project DSDP Gardner, James V Dean, Walter E Wilson, Christine R CaCO3, organic carbon and mass accumulation rates at DSDP Site 75-532, supplement to: Gardner, James V; Dean, Walter E; Wilson, Christine R (1984): Carbonate and organic-carbon cycles and the history of upwelling at Deep Sea Drilling Project Site 532, Walvis Ridge, South Atlantic Ocean. In: Hay, WW; Sibuet, J-C; et al. (eds.), Initial Reports of the Deep Sea Drilling Project (U.S. Govt. Printing Office), 75, 905-921 |
topic_facet |
Drilling/drill rig Leg75 Glomar Challenger Deep Sea Drilling Project DSDP |
description |
Detailed carbonate and organic-carbon stratigraphies were constructed from samples collected every 20 cm in a 250-m hydraulic piston core recovered at DSDP Site 532 on Walvis Ridge. This sampling interval represents about one sample every 5000 yr., based on sediment accumulation rates calculated from nannofossil biostratigraphic zones. All samples were analyzed for percent CaCO3, resulting in a detailed carbonate stratigraphy for the past 5.0 m.y. The samples for the top 110 m of section were also analyzed for organic carbon in order to construct a detailed organiccarbon stratigraphy for the last 2.5 m.y. The recovered section has distinct dark-light color cycles with average periodicities of 55, 58, and 30 k.y. for the Quaternary, upper Pliocene, and lower Pliocene, respectively. Periodicities of carbonate cycles are similar to the color cycles; most carbonate minima correspond to the dark parts of color cycles. The average periodicity for carbonate cycles is about 36 k.y. Darker parts of color cycles usually contain higher concentrations of organic carbon, but the organic- carbon record does not follow the cyclicity of the color cycles in detail, at least for the last 2.5 m.y. Organic-carbon cycles have an average periodicity of about 34 k.y. for the Quaternary and upper Pliocene. The cycles of CaCO3 and color have periodicities similar to those reported from carbonate stratigraphies from the northeast Atlantic, Caribbean, and eastern equatorial Pacific. The carbonate cycles at Site 532 are the result of external forcing, probably related to global climate, that affected fluctuations in both sediment supply from the African continental margin and productivity of siliceous organisms. The organic-carbon cycles have similar periodicities and similar changes in periodicities to those of the CaCO3 cycles. Semiquantitative estimates of diatom abundance from smear slides and concentrations of biogenic SiO2 calculated from chemical analyses suggest that upwelling at Site 532 was minor until about 3 m.y. ago. The Benguela-Current upwelling system either began at that time or, more likely, migrated into the area of Site 532, where it prevailed until some time between about 1.2 and 0.5 m.y. ago. The increase and decline of upwelling in the area of Site 532, however, did not disturb the trend of cyclicities of carbonate and organic carbon. The latest change in conditions at Site 532 was an increase in intensity of bottom currents during the past 0.5 m.y. that winnowed nannofossils, diatoms, and clay and left a lag deposit represented by a foraminifer-rich fades. |
format |
Article in Journal/Newspaper |
author |
Gardner, James V Dean, Walter E Wilson, Christine R |
author_facet |
Gardner, James V Dean, Walter E Wilson, Christine R |
author_sort |
Gardner, James V |
title |
CaCO3, organic carbon and mass accumulation rates at DSDP Site 75-532, supplement to: Gardner, James V; Dean, Walter E; Wilson, Christine R (1984): Carbonate and organic-carbon cycles and the history of upwelling at Deep Sea Drilling Project Site 532, Walvis Ridge, South Atlantic Ocean. In: Hay, WW; Sibuet, J-C; et al. (eds.), Initial Reports of the Deep Sea Drilling Project (U.S. Govt. Printing Office), 75, 905-921 |
title_short |
CaCO3, organic carbon and mass accumulation rates at DSDP Site 75-532, supplement to: Gardner, James V; Dean, Walter E; Wilson, Christine R (1984): Carbonate and organic-carbon cycles and the history of upwelling at Deep Sea Drilling Project Site 532, Walvis Ridge, South Atlantic Ocean. In: Hay, WW; Sibuet, J-C; et al. (eds.), Initial Reports of the Deep Sea Drilling Project (U.S. Govt. Printing Office), 75, 905-921 |
title_full |
CaCO3, organic carbon and mass accumulation rates at DSDP Site 75-532, supplement to: Gardner, James V; Dean, Walter E; Wilson, Christine R (1984): Carbonate and organic-carbon cycles and the history of upwelling at Deep Sea Drilling Project Site 532, Walvis Ridge, South Atlantic Ocean. In: Hay, WW; Sibuet, J-C; et al. (eds.), Initial Reports of the Deep Sea Drilling Project (U.S. Govt. Printing Office), 75, 905-921 |
title_fullStr |
CaCO3, organic carbon and mass accumulation rates at DSDP Site 75-532, supplement to: Gardner, James V; Dean, Walter E; Wilson, Christine R (1984): Carbonate and organic-carbon cycles and the history of upwelling at Deep Sea Drilling Project Site 532, Walvis Ridge, South Atlantic Ocean. In: Hay, WW; Sibuet, J-C; et al. (eds.), Initial Reports of the Deep Sea Drilling Project (U.S. Govt. Printing Office), 75, 905-921 |
title_full_unstemmed |
CaCO3, organic carbon and mass accumulation rates at DSDP Site 75-532, supplement to: Gardner, James V; Dean, Walter E; Wilson, Christine R (1984): Carbonate and organic-carbon cycles and the history of upwelling at Deep Sea Drilling Project Site 532, Walvis Ridge, South Atlantic Ocean. In: Hay, WW; Sibuet, J-C; et al. (eds.), Initial Reports of the Deep Sea Drilling Project (U.S. Govt. Printing Office), 75, 905-921 |
title_sort |
caco3, organic carbon and mass accumulation rates at dsdp site 75-532, supplement to: gardner, james v; dean, walter e; wilson, christine r (1984): carbonate and organic-carbon cycles and the history of upwelling at deep sea drilling project site 532, walvis ridge, south atlantic ocean. in: hay, ww; sibuet, j-c; et al. (eds.), initial reports of the deep sea drilling project (u.s. govt. printing office), 75, 905-921 |
publisher |
PANGAEA - Data Publisher for Earth & Environmental Science |
publishDate |
1984 |
url |
https://dx.doi.org/10.1594/pangaea.810144 https://doi.pangaea.de/10.1594/PANGAEA.810144 |
long_lat |
ENVELOPE(65.903,65.903,-70.411,-70.411) |
geographic |
Gardner Pacific |
geographic_facet |
Gardner Pacific |
genre |
Northeast Atlantic South Atlantic Ocean |
genre_facet |
Northeast Atlantic South Atlantic Ocean |
op_relation |
https://dx.doi.org/10.2973/dsdp.proc.75.126.1984 |
op_rights |
Creative Commons Attribution 3.0 Unported https://creativecommons.org/licenses/by/3.0/legalcode cc-by-3.0 |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1594/pangaea.810144 https://doi.org/10.2973/dsdp.proc.75.126.1984 |
_version_ |
1766143540370341888 |