Gupta, Anil K. et al. (2004): Indian Ocean high-productivity event (10-8 Ma); linked to global cooling or to the initiation of the Indian monsoons?

Leg/Site/Hole:
ODP 121
DSDP 22
DSDP 22 214
DSDP 22 216
ODP 121 752
ODP 121 757
ODP 121 758
Identifier:
2004-070961
georefid

10.1130/G20662.1
doi

Creator:
Gupta, Anil K.
Indian Institute of Technology, Department of Geology and Geophysics, Kharagpur, India
author

Singh, Raj K.
Wesleyan University, United States
author

Joseph, Sudheer
author

Thomas, Ellen
author

Identification:
Indian Ocean high-productivity event (10-8 Ma); linked to global cooling or to the initiation of the Indian monsoons?
2004
Geology (Boulder)
Geological Society of America (GSA), Boulder, CO, United States
32
9
753-756
Uplift of the Himalayas and Tibetan Plateau (ca. 10-8 Ma) has been said to be the main cause of the origin or intensification of the Indian monsoon system, because mountains modulate the land-sea thermal contrast. The intensification of the monsoons, in turn, is seen as the cause of major changes in fauna and flora on land (as a result of changing precipitation patterns) as well as in the Indian Ocean, where the monsoons drive increased upwelling and thus increased productivity. We argue that the interactions between the elevation of the Himalayas and Tibetan Plateau, the onset of the monsoons, and their effects on the Indian Ocean biota remain uncertain. The timing of these events (uplift, monsoons, and biotic change) is not well constrained. Neogene deep-sea benthic foraminiferal faunal and isotope records of the Ninetyeast Ridge combined with published data show that a major increase in biogenic productivity occurred at 10-8 Ma throughout the Indian Ocean, the equatorial Pacific, and southern Atlantic. We suggest that this Indian Ocean high-productivity event was not simply the result of monsoon-induced upwelling or nutrient delivery from the weathering of newly uplifted mountains, but may have been caused by strengthened wind regimes resulting from global cooling and the increase in volume of the Antarctic ice sheets.
English
Serial
Coverage:Geographic coordinates:
North:5.2303
West:88.1048East: 93.3440
South:-30.5329

Quaternary geology; Antarctic ice sheet; Antarctica; Asia; benthic taxa; biofacies; C-13/C-12; carbon; Cenozoic; cluster analysis; cooling; cores; Deep Sea Drilling Project; deep-sea environment; DSDP Site 214; DSDP Site 216; factor analysis; Foraminifera; geochemistry; glacial environment; glacial geology; glaciomarine environment; Holocene; ice sheets; India; Indian Ocean; Indian Peninsula; Invertebrata; isotope ratios; isotopes; Leg 121; Leg 22; marine environment; marine sediments; microfossils; monsoons; Neogene; Ninetyeast Ridge; O-18/O-16; Ocean Drilling Program; ODP Site 752; ODP Site 757; ODP Site 758; oxygen; paleo-oceanography; paleoclimatology; productivity; Protista; Quaternary; sediments; stable isotopes; statistical analysis; Tertiary;

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