Evaluation of the CaCO3 dissolution proxies in sediment cores from above the lysocline
DRS at CSIR-National Institute of Oceanography
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Title |
Evaluation of the CaCO3 dissolution proxies in sediment cores from above the lysocline
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Creator |
Naik, S.S.
Naidu, P.D. |
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Subject |
Calcium carbonate analyses
sediment cores Indian Ocean foraminifera |
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Description |
Calcium carbonate analyses were carried out from two size fractions (less than 63 mu m and more than 63 mu m) from the Ocean Drilling Program Sites 752 and 715 collected from above the lysocline depth in the Indian Ocean, to evaluate the calcium carbonate size index as paleocarbonate ion proxy in these cores. Size index values varied from 69 to 81 at Site 752 and showed a similar pattern with that of total carbonate content at this site. High values of size index and the location of this site, far from any landmass, suggest that only changes in productivity of overlying waters are responsible for the observed variations. Low values of size index at Site 715 suggest supralysoclinal dissolution, the inverse relation between size index variations and the total CaCO sub(3) content shows that the total carbonate variations are controlled by the finer fraction composed of juvenile foraminifera, foraminifera fragments and coccolithophores. This further confirms the observed variations of CaCO sub(3) content of the less than 63 mm fraction, which follows the trend of total CaCO sub(3) content. This study demonstrates that apart from factors such as breakup of shells after burial due to organic matter respiration and dilution due to terrigenous material, changes in surface water productivity and coccolithophores might be a constraint to use size index as a paleocarbonate ion proxy for sediments from above the lysocline.
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Date |
2010-03-09T11:43:36Z
2010-03-09T11:43:36Z 2010 |
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Type |
Journal Article
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Identifier |
Quaternary International, vol.213(1-2); 69-73
http://drs.nio.org/drs/handle/2264/3565 |
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Language |
en
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Rights |
An edited version of this paper was published by Elsevier. Copyright [2010] Elsevier
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Publisher |
Elsevier
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