Paleoceanographic changes of the Indian Ocean and corresponding tectonic events recorded in the Himalayan Range

Author(s): Nishi, Hiroshi; Sakai, Harutaka
Author Affiliation(s): Primary:
Tohoku University, Institute of Geology and Paleontology, Sendai, Japan
Kyushu University, Japan
Volume Title: Environment changes recorded in the Himalayan Range and Indian Ocean
Source: Environment changes recorded in the Himalayan Range and Indian Ocean. Chishitsugaku Zasshi = Journal of the Geological Society of Japan, 103(3), p.313-327. Publisher: Nippon Chishitsugaku Gakkai, Tokyo, Japan. ISSN: 0016-7630 CODEN: CHTZA5
Note: In Japanese with English summary. 109 refs.Special issue; illus.
Summary: This paper reviews the tectonic and paleoceanographic events based on the investigation of ODP legs 115 to 123 in the Indian Ocean, and discusses the interaction between events which occurred in the Indian Ocean and in the Himalayan Range. ODP Leg 122 and 123 revealed that the incipient Indian Ocean formed at Argo Abyssal Plain, off the northwest Australia after the late Jurassic breakup of eastern Gondwana. Purely pelagic sediments began to be deposited after the Cenomanian/Turonian anoxic event. The terminal events of the Cretaceous/Paleogene and Paleocene/Eocene boundaries were recovered in some cores of Legs 119 to 122. The study of Cenozoic magnetic anomalies in the Indian Ocean confirms that the collision between India and Eurasia began between 53 to 55 Ma (the middle Eocene) and coincides with the initiation of global oceanographic cooling based on paleontological and geochemical data. Sedimentation in the Ganges-Indus submarine fan complexes is controlled by uplift and denudation of the Himalayan Range. The analysis of detrital heavy minerals in the cores of ODP leg 116 indicates two-phase episodic uplift of the Higher Himalayas, dated at 10.9-7.5 Ma and after 0.9 Ma. Monsoonal upwelling in the Indian Ocean started at about 10 Ma, and may represent the appearance of extensive high mountains and plateau. In the Quaternary, the upwelling records of the western Arabian Sea suggest that southwest summer monsoon became strong during interglacial times, and weak during glacial times.
Year of Publication: 1997
Research Program: ODP Ocean Drilling Program
Key Words: 07 Marine Geology and Oceanography; 12 Stratigraphy, Historical Geology and Paleoecology; Asia; C-13/C-12; Carbon; Cenozoic; Climate change; Foraminifera; Geochemistry; Glacial environment; Gondwana; Himalayas; Indian Ocean; Interglacial environment; Invertebrata; Isotope ratios; Isotopes; Magnetic anomalies; Marine sediments; Mesozoic; Metamorphism; Monsoons; O-18/O-16; Ocean Drilling Program; Ocean circulation; Oxygen; Paleo-oceanography; Paleocirculation; Paleoclimatology; Paleoenvironment; Paleogeography; Paleotemperature; Plate collision; Plate tectonics; Protista; Sediments; Stable isotopes; Tectonics
Record ID: 1998032124
Copyright Information: GeoRef, Copyright 2017 American Geosciences Institute.

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