Quaternary carbonate record of ODP Hole 115-709A
The CaCO3 content in Quaternary deep-sea sediments from Pacific and Atlantic oceans have been suggested to respond differently to glacial/interglacial cycles; CaCO3 contents are highest during glacials in the Pacific but highest during interglacials in the Atlantic Ocean. It is not yet clear as to w...
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ftpangaea:oai:pangaea.de:doi:10.1594/PANGAEA.758731 2024-09-15T18:31:08+00:00 Quaternary carbonate record of ODP Hole 115-709A Naidu, Pothuri Divakar Malmgren, Bjorn LATITUDE: -3.915000 * LONGITUDE: 60.551700 * DATE/TIME START: 1987-06-05T01:30:00 * DATE/TIME END: 1987-06-06T06:30:00 1999 application/zip, 2 datasets https://doi.pangaea.de/10.1594/PANGAEA.758731 https://doi.org/10.1594/PANGAEA.758731 en eng PANGAEA https://doi.pangaea.de/10.1594/PANGAEA.758731 https://doi.org/10.1594/PANGAEA.758731 CC-BY-3.0: Creative Commons Attribution 3.0 Unported Access constraints: unrestricted info:eu-repo/semantics/openAccess Supplement to: Naidu, Pothuri Divakar; Malmgren, Bjorn (1999): Quaternary carbonate record from the equatorial Indian Ocean and its relationship with productivity changes. Marine Geology, 161(1), 49-62, https://doi.org/10.1016/S0025-3227(99)00055-9 115-709A DRILL Drilling/drill rig Joides Resolution Leg115 Ocean Drilling Program ODP South Indian Ridge South Indian Ocean dataset publication series 1999 ftpangaea https://doi.org/10.1594/PANGAEA.75873110.1016/S0025-3227(99)00055-9 2024-07-24T02:31:20Z The CaCO3 content in Quaternary deep-sea sediments from Pacific and Atlantic oceans have been suggested to respond differently to glacial/interglacial cycles; CaCO3 contents are highest during glacials in the Pacific but highest during interglacials in the Atlantic Ocean. It is not yet clear as to whether a Pacific or an Atlantic pattern of CaCO3 fluctuations dominates the Indian Ocean. We have analyzed the Ocean Drilling Program (ODP) Site 709A from the western equatorial Indian Ocean for the last 1370 ka to determine the relationships between percentages and fluxes of CaCO3 and Quaternary paleoclimatic changes. We also analyzed the coarse (>25 µm) and fine (<25 µm) fractions of CaCO3 in an attempt at estimating the influence of differences in productivity of foraminifera and calcareous nannofossils in shaping the CaCO3 record. Carbon isotopes and Ba/Al ratios were used as indices of productivity. Percentages and fluxes of CaCO3 in the total sediment and <25 µm fraction do not show any clear relationships to glacial/interglacial cycles derived from d18O of the planktonic foraminifera Globigerinoides ruber. This indicates that CaCO3 fluctuations at this site do not show either a Pacific or an Atlantic pattern of CaCO3 fluctuations. Fluxes of CaCO3 (0.38 to 2.46 g/cm**2/ ka) in total sediment and Ba/Al ratios (0.58 to 3.93 g/cm**2/ka) show six-fold variability through the last 1370 ka, which points out that productivity changes are significant at this site. Fluxes of the fine CaCO3 component demonstrate a 26-fold change (0.02 to 0.52 g/cm**2/ka), whereas the coarse CaCO3 component exhibit eight-fold change (0.13 to 1.07 g/cm**2/ka). This suggests that productivity variations of calcareous nannofossils are greater in comparison with the foraminifera. On the other hand, mean values of coarse CaCO3 fluxes are higher compared to those of fine CaCO3, which reveals that the foraminifera contribute more to the bulk CaCO3 flux than the calcareous nannofossils in the equatorial Indian Ocean. Other/Unknown Material Planktonic foraminifera PANGAEA - Data Publisher for Earth & Environmental Science ENVELOPE(60.551700,60.551700,-3.915000,-3.915000) |
institution |
Open Polar |
collection |
PANGAEA - Data Publisher for Earth & Environmental Science |
op_collection_id |
ftpangaea |
language |
English |
topic |
115-709A DRILL Drilling/drill rig Joides Resolution Leg115 Ocean Drilling Program ODP South Indian Ridge South Indian Ocean |
spellingShingle |
115-709A DRILL Drilling/drill rig Joides Resolution Leg115 Ocean Drilling Program ODP South Indian Ridge South Indian Ocean Naidu, Pothuri Divakar Malmgren, Bjorn Quaternary carbonate record of ODP Hole 115-709A |
topic_facet |
115-709A DRILL Drilling/drill rig Joides Resolution Leg115 Ocean Drilling Program ODP South Indian Ridge South Indian Ocean |
description |
The CaCO3 content in Quaternary deep-sea sediments from Pacific and Atlantic oceans have been suggested to respond differently to glacial/interglacial cycles; CaCO3 contents are highest during glacials in the Pacific but highest during interglacials in the Atlantic Ocean. It is not yet clear as to whether a Pacific or an Atlantic pattern of CaCO3 fluctuations dominates the Indian Ocean. We have analyzed the Ocean Drilling Program (ODP) Site 709A from the western equatorial Indian Ocean for the last 1370 ka to determine the relationships between percentages and fluxes of CaCO3 and Quaternary paleoclimatic changes. We also analyzed the coarse (>25 µm) and fine (<25 µm) fractions of CaCO3 in an attempt at estimating the influence of differences in productivity of foraminifera and calcareous nannofossils in shaping the CaCO3 record. Carbon isotopes and Ba/Al ratios were used as indices of productivity. Percentages and fluxes of CaCO3 in the total sediment and <25 µm fraction do not show any clear relationships to glacial/interglacial cycles derived from d18O of the planktonic foraminifera Globigerinoides ruber. This indicates that CaCO3 fluctuations at this site do not show either a Pacific or an Atlantic pattern of CaCO3 fluctuations. Fluxes of CaCO3 (0.38 to 2.46 g/cm**2/ ka) in total sediment and Ba/Al ratios (0.58 to 3.93 g/cm**2/ka) show six-fold variability through the last 1370 ka, which points out that productivity changes are significant at this site. Fluxes of the fine CaCO3 component demonstrate a 26-fold change (0.02 to 0.52 g/cm**2/ka), whereas the coarse CaCO3 component exhibit eight-fold change (0.13 to 1.07 g/cm**2/ka). This suggests that productivity variations of calcareous nannofossils are greater in comparison with the foraminifera. On the other hand, mean values of coarse CaCO3 fluxes are higher compared to those of fine CaCO3, which reveals that the foraminifera contribute more to the bulk CaCO3 flux than the calcareous nannofossils in the equatorial Indian Ocean. |
format |
Other/Unknown Material |
author |
Naidu, Pothuri Divakar Malmgren, Bjorn |
author_facet |
Naidu, Pothuri Divakar Malmgren, Bjorn |
author_sort |
Naidu, Pothuri Divakar |
title |
Quaternary carbonate record of ODP Hole 115-709A |
title_short |
Quaternary carbonate record of ODP Hole 115-709A |
title_full |
Quaternary carbonate record of ODP Hole 115-709A |
title_fullStr |
Quaternary carbonate record of ODP Hole 115-709A |
title_full_unstemmed |
Quaternary carbonate record of ODP Hole 115-709A |
title_sort |
quaternary carbonate record of odp hole 115-709a |
publisher |
PANGAEA |
publishDate |
1999 |
url |
https://doi.pangaea.de/10.1594/PANGAEA.758731 https://doi.org/10.1594/PANGAEA.758731 |
op_coverage |
LATITUDE: -3.915000 * LONGITUDE: 60.551700 * DATE/TIME START: 1987-06-05T01:30:00 * DATE/TIME END: 1987-06-06T06:30:00 |
long_lat |
ENVELOPE(60.551700,60.551700,-3.915000,-3.915000) |
genre |
Planktonic foraminifera |
genre_facet |
Planktonic foraminifera |
op_source |
Supplement to: Naidu, Pothuri Divakar; Malmgren, Bjorn (1999): Quaternary carbonate record from the equatorial Indian Ocean and its relationship with productivity changes. Marine Geology, 161(1), 49-62, https://doi.org/10.1016/S0025-3227(99)00055-9 |
op_relation |
https://doi.pangaea.de/10.1594/PANGAEA.758731 https://doi.org/10.1594/PANGAEA.758731 |
op_rights |
CC-BY-3.0: Creative Commons Attribution 3.0 Unported Access constraints: unrestricted info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1594/PANGAEA.75873110.1016/S0025-3227(99)00055-9 |
_version_ |
1810472742360711168 |