Gupta, Anil K. and Das, Moumita (2007): Occurrence of the biogenic bloom in the oligotrophic southeastern Indian Ocean; evidence from late Neogene deep-sea benthic Foraminifera (ODP Hole 752A)
Leg/Site/Hole:
Related Expeditions:
ODP 121 ODP 121 752
Identifier:
ID:
2008-000566
Type:
georefid
Creator:
Name:
Gupta, Anil K.
Affiliation:
Indian Institute of Technology, Department of Geology and Geophysics, Kharagpur, India
Role:
author
Name:
Das, Moumita
Affiliation:
Role:
author
Identification:
Title:
Occurrence of the biogenic bloom in the oligotrophic southeastern Indian Ocean; evidence from late Neogene deep-sea benthic Foraminifera (ODP Hole 752A)
Year:
2007
Source:
Journal of the Geological Society of India
Publisher:
Geological Society of India, Bangalore, India
Volume:
69
Issue:
2
Pages:
331-343
Abstract:
We produced a 12.9 Ma census data of deep-sea benthic foraminifera from subtropical Ocean Drilling Program (ODP) Hole 752A, Broken Ridge, southeastern Indian Ocean to understand paleoceanographic and paleoclimatic changes and their relation to Southern Ocean climate variability as well as latitudinal shifts in the Subtropical Convergence Zone (SCZ). We employed knowledge of the ecology of Recent deep-sea benthic foraminifera from different ocean basins for environmental interpretations at Hole 752A. Benthic faunal data suggest a major transition in deep-sea environments of the southeastern Indian Ocean across 5.5-4.5 Ma roughly coinciding with the end of the Indo-Pacific "biogenic bloom". The benthic biofacies suggest well-oxygenated and nutrient poor deep waters from 12.9 to 10 Ma with variable flux of organic matter. The interval 10-5.5 Ma is marked by high and sustained flux of organic matter at the time when productivity increased many fold throughout the Indian and Pacific Oceans during which time the biogenic bloom peaked and the Indian summer monsoon intensified. Antarctic ice volume significantly increased and southern component deep-water formation enhanced during this time. This southern cooling in the late middle to late Miocene probably pushed the SCZ towards north above Hole 752A. Since 4.5 Ma, the organic flux was low to intermediate and pulsed.
Language:
English
Genre:
Serial
Rights:
URL:
Coverage: Geographic coordinates: North:-30.5328 West:93.3439 East:
93.3440 South:-30.5329
Keywords: Stratigraphy; algae; algal blooms; assemblages; benthic taxa; biofacies; Broken Ridge; Bulimina; Buliminacea; Cenozoic; climate change; Foraminifera; Indian Ocean; Invertebrata; Leg 121; Melonis; microfossils; monsoons; Neogene; nutrients; Ocean Drilling Program; ODP Site 752; paleo-oceanography; paleoclimatology; paleoenvironment; paleogeography; Plantae; Protista; Rotaliina; Tertiary; upper Neogene;
.