Expedition 355 summary

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doi: 101.2016
Author(s): Pandey, Dhananjai K.; Clift, Peter D.; Kulhanek, Denise K.; Ando, Sergio; Bendle, James A. P.; Bratenkov, Sophia; Griffith, Elizabeth M.; Gurumurthy, Gundiga P.; Hahn, Annette; Iwai, Masao; Khim, Boo-Keun; Kumar, Anil; Kumar, A. Ganesh; Liddy, Hannah M.; Lu Huaya; Lyle, Mitchell W.; Mishra, Ravi; Radhakrishna, Tallavajhala; Routledge, Claire M.; Saraswat, Rajeev; Saxena, Rakesh; Scardia, Giancarlo; Sharma, Girish K.; Singh, Arun D.; Steinke, Stephan; Suzuki, Kenta; Tauxe, Lisa; Tiwari, Manish; Xu Zhaokai; Yu, Zhaojie
International Ocean Discovery Program, Expedition 355 Scientists, College Station, TX
Author Affiliation(s): Primary:
National Centre for Antarctic and Ocean, Department of Marine Geophysics, Gao, India
Other:
Louisiana State Uniersity, United States
Texas A&M University, United States
University of Milan Bicocca, Italy
University of Birmingham, United Kingdom
Macquarie University, Australia
University of Texas at Arlington, United States
Manipal University, India
University of Bremen, Germany
Volume Title: Proceedings of the International Ocean Discovery Program; Arabian Sea monsoon; Expedition 355 of the riserless drilling program Colombo, Sri Lanka, to Mumbai, India; Sites U1456-U1457, 31 March - 31 May 2015
Volume Author(s): Pandey, Dhananjai K.; Clift, Peter D.; Kulhanek, Denise K.; Ando, Sergio; Bendle, James A. P.; Bratenkov, Sophia; Griffith, Elizabeth M.; Gurumurthy, Gundiga P.; Hahn, Annette; Iwai, Masao; Khim, Boo-Keun; Kumar, Anil; Kumar, A. Ganesh; Liddy, Hannah M.; Lu Huayu; Lyle, Mitchell W.; Mishra, Ravi; Radhakrishna, Tallavajhala; Routledge, Claire M.; Saraswat, Rajeev; Saxena, Rakesh; Scardia, Giancarlo; Sharma, Girish K.; Singh, Arun D.; Steinke, Stephan; Suzuki, Kenta; Tauxe, Lisa; Tiwari, Manish; Xu Zhaokai; Yu Zhaojie
Source: Proceedings of the International Ocean Discovery Program; Arabian Sea monsoon; Expedition 355 of the riserless drilling program Colombo, Sri Lanka, to Mumbai, India; Sites U1456-U1457, 31 March - 31 May 2015, Dhananjai K. Pandey, Peter D. Clift, Denise K. Kulhanek, Sergio Ando, James A. P. Bendle, Sophia Bratenkov, Elizabeth M. Griffith, Gundiga P. Gurumurthy, Annette Hahn, Masao Iwai, Boo-Keun Khim, Anil Kumar, A. Ganesh Kumar, Hannah M. Liddy, Lu Huayu, Mitchell W. Lyle, Ravi Mishra, Tallavajhala Radhakrishna, Claire M. Routledge, Rajeev Saraswat, Rakesh Saxena, Giancarlo Scardia, Girish K. Sharma, Arun D. Singh, Stephan Steinke, Kenta Suzuki, Lisa Tauxe, Manish Tiwari, Xu Zhaokai and Yu Zhaojie; International Ocean Discovery Program, Expedition 355 Scientists, College Station, TX. Proceedings of the International Ocean Discovery Program, Expedition Reports, Vol.355, 32p. Publisher: International Ocean Discovery Program, Washington, DC, United States. ISSN: 2377-3189 CODEN: IDSDA6
Note: In English. 163 refs.; illus., incl. sects., 1 table, sketch map
Summary: The Indian (southwest) summer monsoon is one of the most intense climatic phenomena on Earth, with its long-term development possibly linked to the growth of high topography in South and Central Asia. The Indian continental margin, adjoining the Arabian Sea, offers a unique opportunity to investigate tectonic-climatic interactions and the net impact of these processes on weathering and erosion of the western Himalaya. During International Ocean Discovery Program Expedition 355, two sites (U1456 and U1457) were drilled in Laxmi Basin in the eastern Arabian Sea to document the coevolution of mountain building, weathering, erosion, and climate over a range of timescales. In addition, recovering basement from the eastern Arabian Sea provides constraints on the early rifting history of the western continental margin of India with special emphasis on continental breakup between India and the Seychelles and its relationship to the plume-related volcanism of the Deccan Plateau. Drilling and coring operations during Expedition 355 recovered sediment from Sites U1456 and U1457 in Laxmi Basin, penetrating 1109.4 and 1108.6 m below seafloor (mbsf), respectively. Drilling reached sediment dated to 13.5 - 17.7 Ma (late early to early middle Miocene) at Site U1456, although with a large hiatus between the lowermost sediment and overlying deposits dated at <10.9 Ma. At Site U1457, a much longer hiatus occurs near the base of the cored section, spanning from ∼10.9 to ∼62 Ma. At both sites, hiatuses span ∼8.2-9.2 and ∼3.6-5.6 Ma with a possible condensed section spanning ∼2.0-2.6 Ma, although the total duration for each hiatus is slightly different between the two sites. A major submarine fan probably draining the western Himalaya and Karakoram must have been supplying sediment to the eastern Arabian Sea since at least ∼17 Ma. Sand mineral assemblages indicate that the Greater Himalayan Crystalline Sequence was fully exposed to the surface by this time. Most of the recovered sediment appears to be derived from the Indus River and includes minerals that are unique to the Indus Suture Zone, in particular glaucophane and hypersthene, most likely originating from the structural base of the Kohistan arc (i.e., within the Indus Suture Zone). Pliocene sandy intervals at Site U1456 were deposited in lower fan "sheet lobe" settings, with intervals of basin-plain turbidites separated by hemipelagic muddy sections deposited during the Miocene. Site U1457 is more distal in facies, reflecting its more marginal setting. No major active lobe appears to have affected Laxmi Basin since the late early Pleistocene (∼1.2-1.5 Ma). We succeeded in recovering sections spanning the 8 Ma climatic transition, when monsoon intensity is believed to have changed strongly, although the nature of this change awaits postcruise analysis. We also recovered sediment from large mass transport deposits measuring ∼330 and ∼190 m thick at Sites U1456 and U1457, respectively. These sections include an upper sequence of slumpfolded muddy and silty rocks, as well as underlying calcarenites and limestone breccias, together with smaller amounts of volcanic clasts, all of which are likely derived from the western Indian continental shelf. Identification of similar facies on the regional seismic lines in Laxmi Basin suggests that these deposits form parts of one of the world's largest mass transport deposits. Coring of igneous basement was achieved at Site U1457. Recovery of massive basalt and associated volcaniclastic sediment at this site should address the key questions related to rifting and volcanism associated with formation of Laxmi Basin. Geochemical analysis indicates that these are low-K, high-Mg subalkaline tholeiitic basalts and do not represent a typical mid-ocean-ridge basalt. Other observations made at the two sites during Expedition 355 provide vital constraints on the rift history of this margin. Heat flow measurements at the two drill sites were calculated to be ∼57 and ∼60 mW/m2. Such heat flow values are compatible with those observed in average oceanic crust of 63-84 Ma age, as well as with the presence of highly extended continental crust. Postcruise analyses of the more than ∼1722 m of core will provide further information about the nature of tectonic-climatic interactions in this global type area for such studies.
Year of Publication: 2016
Research Program: IODP Integrated Ocean Drilling Program
IODP2 International Ocean Discovery Program
Key Words: 12 Stratigraphy, Historical Geology and Paleoecology; Algae; Arabian Sea; Biostratigraphy; Cenozoic; Climate change; Cores; Diatoms; Expedition 355; Foraminifera; Geophysical methods; Geophysical profiles; Geophysical surveys; Heavy minerals; IODP Site U1456; IODP Site U1457; Indian Ocean; International Ocean Discovery Program; Invertebrata; Laxmi Basin; Lithofacies; Lithostratigraphy; Mass movements; Microfossils; Mineral assemblages; Monsoons; Nannofossils; Paleoclimatology; Plantae; Protista; Provenance; Quaternary; Radiolaria; Sediment transport; Seismic methods; Seismic profiles; Seismic stratigraphy; Surveys; Tertiary; Transport; Well logs
Coordinates: N163717 N163717 E0685021 E0685021
N170957 N170957 E0675548 E0675548
Record ID: 2016081492
Copyright Information: GeoRef, Copyright 2018 American Geosciences Institute.
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