Some aspects on the variations in depositional flux of excess Thorium-230 in the central Indian basin during Late Quaternary
DRS at CSIR-National Institute of Oceanography
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Title |
Some aspects on the variations in depositional flux of excess Thorium-230 in the central Indian basin during Late Quaternary
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Creator |
Sukumaran, N.P.
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Subject |
Oceanography and Limnology
thorium isotopes depositional features seasonal variations Quaternary ISW, Central Indian Ocean |
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Description |
Examined in this paper is the tentative history of the depositional flux of @u230@@Th@dxs@@ (the unsupported fraction of @u230@@Th scavenged from the overlying water column), for the Late Quaternary period from a sediment core of the Central Indian Basin (CIB). The measured depositional flux of @u230@@Th@dxs is found substantially higher than that of the possible theoretical flux from the overlying water column. Historical records, reconstructed from the @u230@@Th@dxs@@ chronology suggests that the depositional flux has varied considerably with time, reflecting an enhanced scavenging during the Holocene and the preceding interglacial periods whereas, comparatively lower flux than the predicted one occurred during the Last Glacial Maximum (LGM) period. The average ratio of the measured depositional flux to that of the predicted flux from the overlying water column, indicates that the core site acts as a sink for @u230@@Th@dxs@@ and based on the existence of bottom current activity; the @u230@@Th@dxs could be the result of focusing of younger sediments. The depositional index (Di) has also been calculated to quantify the extent of lateral supply throughout the core with time. The estimated (Di) suggests that bottom focusing and feeble deposition and/or winnowing processes had occurred and that the former was most prevalent during the Holocene and the preceding interglacials, whereas the latter was observed at the LGM period
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Date |
1995-05-04T10:06:30Z
2017-09-30T01:56:27Z 1995-05-04T10:06:30Z 2017-09-30T01:56:27Z 1994 |
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Type |
Journal Article
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Identifier |
Proceedings of the Indian Academy of Sciences (Earth and Planetary Sciences), vol.103(4); 1994; 489-497
0253-4126 http://drs.nio.org/drs/handle/2264/7435 |
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Language |
en
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Relation |
P Indian As-Earth
SCI |
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Publisher |
Indian Academy of Sciences, Bangalore
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