Paleoceanographic evolution of the Northeastern Indian Ocean during the Miocene: evidence from deep-sea benthic foraminifera (DSDP Hole 216A)

• Main Authors: Bhaumik, Ajoy K., Gupta, Anil K., Sundar Raj, M., Mohan, K., De, Soma, Sarkar, Sudipta
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: National Institute of Science Communication and Information Resources 2007
• Subjects: QE Geology; Indian; Antarc*; Antarctica
• Online Access: http://repository.ias.ac.in/63273/; http://www.niscair.res.in/sciencecommunication/researchjournals/rejour/ijms/ijms2k7/ijms_dec07.asp#p6

Statistical analyses (factor and cluster) were performed on 30 highest ranked deep-sea benthic foraminifer species from > 149 µm size fraction from Deep Sea Drilling Project Hole 216A to understand Miocene (~20.5 to ~7 Ma) paleoceanographic evolution of the northeastern Indian Ocean. Factor and cluster analyses enabled us to identify five biofacies defining five clusters. Known ecological preferences of benthic foraminifera were used for environmental interpretations. The faunal data documents a shift in deep-sea ventilation and productivity at 15-14 Ma, coinciding with the abrupt cooling in the middle Miocene. This coincides with the beginning of permanent ice sheets in Antarctica during the middle Miocene.