Data report; 87Sr/86Sr in pore fluids from Expedition 362

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doi: 10.14379/iodp.proc.362.201.2019
Author(s): McCarthy, Morgan; Zirkle, Breeanna; Torres, Marta E.; Haley, Brian A.
International Ocean Discovery Program, Expedition 326 Scientists, College Station, TX
Author Affiliation(s): Primary:
Oregon State University, College of Earth, Ocean and Atmospheric Sciences, Covallis, OR, United States
Volume Title: Proceedings of the International Ocean Discovery Program; Sumatra subduction zone; Expedition 362 of the riserless drilling platform, Colombo, Sri Lanka, to Singapore; Sites U1480-U1481, 6 August-6 October 2016
Volume Author(s): McNeill, Lisa C.; Dugan, Brandon; Petronotis, Katerina E.; Backman, Jan; Bourlange, Sylvain; Chemale, Farid, Jr.; Chen Wenhuang; Colson, Tobias A.; Frederik, Marina C. G.; Guérin, Gilles; Hamahashi, Mari; Pouderoux, Hugo F. A.; Shan Yehua; Song, Insun; Torres, Marta E.; Vannucchi Paola; Vrolijk, Peter J.; Yang Tao; Zhao, Xixi
Source: Proceedings of the International Ocean Discovery Program; Sumatra subduction zone; Expedition 362 of the riserless drilling platform, Colombo, Sri Lanka, to Singapore; Sites U1480-U1481, 6 August-6 October 2016, Lisa C. McNeill, Brandon Dugan, Katerina E. Petronotis, Jan Backman, Sylvain Bourlange, Farid Chemale, Jr., Chen Wenhuang, Tobias A. Colson, Marina C. G. Frederik, Gilles Guérin, Mari Hamahashi, Hugo F. A. Pouderoux, Shan Yehua, Insun Song, Marta E. Torres, Vannucchi Paola, Peter J. Vrolijk, Yang Tao and Xixi Zhao; International Ocean Discovery Program, Expedition 326 Scientists, College Station, TX. Proceedings of the International Ocean Discovery Program, Expedition Reports, Vol.362, 5p. Publisher: International Ocean Discovery Program, Washington, DC, United States. ISSN: 2377-3189 CODEN: IDSDA6
Note: In English. 17 refs.; illus., incl. sects., sketch map
Summary: We report on the Sr isotopic composition of pore fluids recovered from Sites U1480 and U1481 drilled during International Ocean Discovery Program Expedition 362, which sampled the incoming sedimentary section of North Sumatra to investigate the causes of shallow seismogenesis in the Sumatra-Andaman margin. Sr isotope data are valuable in identifying diagenetic alteration of the incoming sequence, which can alter mechanical properties of the sedimentary wedge and subsequently affect its seismogenic behavior. Site U1480 recovered input sediment to ∼1420 meters below seafloor (mbsf), and sediment was sampled from 1150 to 1500 mbsf at Site U1481. To determine the Sr isotopic composition, acidified pore fluid samples recovered at sea were loaded directly onto columns containing EICHROM Sr-Spec resin and followed by analyses using a NU multicollector inductively coupled plasma-mass spectrometer (MC-ICPMS). We observed a marked increase in 87Sr/86Sr ratios to 0.71376 in the Sr contribution from alteration of terrigenous material from the Bengal-Nicobar Fan. This trend is reversed in the deeper sequence, where 87Sr/86Sr ratios decrease to 0.70820 in the deepest sample analyzed (1300 mbsf). Only the deepest sediment was recovered at Site U1481, and the pore fluids also show a decrease in 87Sr/86Sr ratios from 0.71296 at 1172 mbsf to 0.70913 at 1495 mbsf.
Year of Publication: 2019
Research Program: IODP Integrated Ocean Drilling Program
IODP2 International Ocean Discovery Program
Key Words: 02 Geochemistry; 12 Stratigraphy, Historical Geology and Paleoecology; Alkaline earth metals; Cenozoic; Chemostratigraphy; Cores; Cretaceous; Expedition 362; Geochemistry; Hydrochemistry; IODP Site U1480; IODP Site U1481; Indian Ocean; International Ocean Discovery Program; Isotope ratios; Isotopes; Marine sediments; Mesozoic; Metals; Pleistocene; Pore water; Quaternary; Sediments; Sr-87/Sr-86; Stable isotopes; Strontium; Tertiary; Upper Cretaceous
Coordinates: N030203 N030203 E0913621 E0913621
N024516 N024516 E0914535 E0914535
Record ID: 2019016931
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute.