Climate induced changes in the circulation and dispersal patterns of the fluvial sources during late Quaternary in the middle Bengal Fan
IR@NIO: CSIR-National Institute Of Oceanography, Goa
View Archive Info| Field | Value | |
| Creator |
Chauhan, O.S.
Vogelsang, E. |
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| Date |
2006-06-30T05:16:10Z
2006-06-30T05:16:10Z 2006 |
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| Identifier |
Journal of Earth System Science, vol. 115(3), 379–386p.
http://drs.nio.org/drs/handle/2264/176 |
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| Description |
From a transact along 15˚N latitude in the middle Bengal Fan, temporal and spatial variations in the granulometric parameters and clay minerals in 14C dated box cores from the eastern, the central and the western regions were studied to determine climate induced changes in the hydrography. Clay assemblages have spatial and temporal changes and are markedly di?erent in the eastern and the western bay. From a high abundance of the clay smectite, which has its major source in the Deccan Basalt in peninsular India, it is inferred that the western bay is predominantly a depocenter of ‘peninsular sources’. The eastern and the central regions of the bay, however, mostly receive sediments of the ‘Himalayan source’. Related to unstable climate, the reported dominant illite–chlorite (I + C) assemblage in the eastern region of the bay (I + C > 60% smectite <15%), between 18 and 12.6 ka BP, points to a predominant supply from the Himalayan sources through equatorwards dispersal by the winter hydrography. Higher smectite, and reduced clays of the Himalayan sources (smectite >25%; I + C > 45%) are reported also after 12.5 ka BP from the eastern bay. These are interpreted as evidences of an intensi?ed SW monsoon and associated change in the dispersal pattern by stronger summer monsoon hydrography which supports across bay dispersal by anticyclonic gyre. The in?uence of climate on hydrographic changes is consistent during the short events of arid climate (weak NE monsoon) in Holocene in core 31/1(western bay), in which the enhanced contents of the clays of the Himalayan sources are observed (smectite <40% I + C > 50%). These ?ndings have implications for climate regulated influence of fluvial processes over the areas, hitherto, considered unaffected by the Indian peninsular fluvial sources.
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820154 bytes
application/pdf |
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| Language |
en
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| Publisher |
Indian Academy of Sciences
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| Subject |
Himalayan sources
Bengal Fan dispersal patterns clay minerals |
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| Title |
Climate induced changes in the circulation and dispersal patterns of the fluvial sources during late Quaternary in the middle Bengal Fan
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| Type |
Article
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