International Ocean Discovery Program, Expedition 354 Scientific Prospectus; Bengal Fan; Neogene and late Paleogene record of Himalayan Orogeny and climate; a transect across the middle Bengal Fan

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doi: 10.14379/iodp.sp.354.2014
Author(s): France-Lanord, Christian; Schwenk, Tilmann; Klaus, Adam
Author Affiliation(s): Primary:
Université de Lorraine, Centre de Recherches Pétrographiques et Géochimique, Vandoeuvre les Nancy, France
University of Bremen, Germany
Texas A&M University, United States
Source: Scientific Prospectus (International Ocean Discovery Program), Vol.354, 51p. Publisher: International Ocean Discovery Program, College Station, TX, United States. ISSN: 2332-1385
Note: In English. 73 refs.
Summary: Expedition 354 will drill a transect of holes in the Bay of Bengal to address interactions among the growth of the Himalaya and Tibet, the development of the Asian monsoon, and processes affecting the carbon cycle and global climate. Because sedimentation in the Bengal Fan responds to both climate and tectonic processes, its terrigenous sediment records the past evolution of both the Himalaya and regional climate. The histories of the Himalayan/ Tibetan system and the Asian monsoon require sampling different periods of time with different levels of precision. Accordingly, we propose a transect of six holes in the fan at 8°N with two complementary objectives. (1) We will study the early stages of Himalayan erosion, which will bear on the India-Eurasia collision and the development of the Himalaya and Tibet as topographic features. We will drill a deep site (MBF-3A to ∼1500 m) in the west flank of the Ninetyeast Ridge where a reflector interpreted as a Paleocene-Eocene unconformity could be reached at a reasonable depth. (2) We will study the Neogene development of the Asian monsoon and its impact on sediment supply and flux. Our east- west transect of drill sites at 8°N will include Site MBF-3A and two other 900 m penetration sites (MBF-1A and MBF-2A) to reach sediment at least as old as 10-12 m.y. Records from the Arabian Sea and the Indian subcontinent suggest that at ∼7-8 Ma the intensity of the monsoon increased and C4 plants expanded. Moreover, these changes appear to be linked to changes in the erosional regime as recorded by Ocean Drilling Program Leg 116 and possibly to the tectonic evolution of southeast Asia. This transect will allow study of the extent to which a strengthening of the monsoon encompassed the Bay of Bengal, where increased rainfall, not strengthened wind, characterizes the monsoon, and will allow quantitative studies of the interrelations of climate change and sediment accumulation. In addition, three sites (MBF-4A, MBF- 5A, and MBF-6A) will document how the depocenter migrated across this transect during the Pleistocene and will provide the most complete record of channel-derived terrigenous material through this time interval.
Year of Publication: 2014
Research Program: IODP Integrated Ocean Drilling Program
IODP2 International Ocean Discovery Program
Key Words: 12 Stratigraphy, Historical Geology and Paleoecology; 20 Geophysics, Applied; Asia; Bay of Bengal; Bengal Fan; Boreholes; Cenozoic; Drilling; Expedition 354; Geophysical methods; Geophysical profiles; Geophysical surveys; Himalayan Orogeny; Indian Ocean; Integrated Ocean Drilling Program; International Ocean Discovery Program; Lithostratigraphy; Marine drilling; Marine sediments; Neogene; Paleoclimatology; Planning; Quaternary; Sediments; Seismic methods; Seismic profiles; Southern Asia; Surveys; Tectonics; Tertiary; Vertical seismic profiles
Coordinates: N080025 N080025 E0884400 E0861700
Record ID: 2014018612
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