Sediment pathways and emergence of Himalayan source material in the Bay of Bengal
DRS at CSIR-National Institute of Oceanography
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Title |
Sediment pathways and emergence of Himalayan source material in the Bay of Bengal
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Creator |
Krishna, K.S.
Ismaiel, M. Srinivas, K. Gopala Rao, D. Mishra, J. Saha, D. |
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Subject |
GEOLOGY AND GEOPHYSICS
GEOLOGY AND GEOPHYSICS GEOLOGY AND GEOPHYSICS GEOLOGY AND GEOPHYSICS |
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Description |
The sediment succession in the Bay of Bengal (BoB) records the signatures corresponding to India–Asia collision, regional climate change, and erosional proc- esses of both the Himalayan orogen and Indian subcontinent. The Bengal Fan – the world’s largest submarine fan – has long been studied to understand the link between the Himalayan tectonics and Asian monsoon. But, lack of detailed information on corre- sponding signals hampered the understanding of related processes of tectonics, climate and erosion. The pre- sent study of long-streamer seismic reflection profile data and information from deep drill well logs in the western BoB has revealed two different phases of sediment deposition. In the first phase, until Oligo- cene–Miocene (~23 Ma), Indian peninsular rivers dis-charged sediments to the BoB which accumulated at a rate ~20 m/m.y. with an aberration of two fairly enhanced sediment pulses during the periods from 65 to 54 Ma and 34 to 23 Ma. In the second phase, since 23 Ma, the Ganges and Brahmaputra rivers added huge volumes of sediments to the bay at variable rates ranging from 40 to >1000 m/m.y. A distinct increase in sediment discharge (~140 m/m.y.) during the Oligo- cene–Miocene (~23 Ma) together with the develop- ment of regional onlap unconformity and the start of turbidity system provide an important age marker corresponding to rapid exhumation of the Himalaya, which intensified the erosional process and com- mencement of Bengal Fan sedimentation. Further rise in the rate of sedimentation during the period 6.8– 0.8 Ma is coincident with the change in monsoon in- tensity, but surprisingly not in agreement with the de- crease in sediment rate reported at ODP Leg 116 sites in the distal Bengal Fan. Here we provide well- constrained ages for the commencement and growth of the Bengal Fan, which can serve as benchmark in- formation for understanding the interaction between the Himalayan exhumation and Asian climate
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Date |
2016-03-09T08:52:19Z
2016-03-09T08:52:19Z 2016 |
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Type |
Journal Article
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Identifier |
Current Science, vol.110(3); 2016; 363-372
http://drs.nio.org/drs/handle/2264/4921 |
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Language |
en
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Rights |
Copyright [2016]. All efforts have been made to respect the copyright to the best of our knowledge. Inadvertent omissions, if brought to our notice, stand for correction and withdrawal of document from this repository
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Publisher |
Current Science Association
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