Ostracod-based reconstruction of bottom water conditions in the inner sea of the Maldives during the Pleistocene (IODP Site U1467, northern Indian Ocean)

Author(s): Alvarez Zarikian, Carlos A.; Nadiri, Chimnaz; Alonso-Garcia, Montserrat; Petruny, Loren M.; Hernandez, Particia; Kroon, Dick; Wright, James; Eberli, Gregor P.; Betzler, Christian
Author Affiliation(s): Primary:
Texas A&M University, International Ocean Discovery Program, College Station, TX, United States
Other:
Universidade do Algarve, Portugal
Smithsonian Institution National Museum of Natural History, United States
University of Edinburgh, United Kingdom
Rutgers University, United States
University of Miami, United States
University of Hamburg, Germany
Volume Title: Geological Society of America, 2017 annual meeting & exposition
Source: Abstracts with Programs - Geological Society of America, 49(6); Geological Society of America, 2017 annual meeting & exposition, Seattle, WA, Oct. 22-25, 2017. Publisher: Geological Society of America (GSA), Boulder, CO, United States. ISSN: 0016-7592 CODEN: GAAPBC
Note: In English
Summary: The Maldives carbonate archipelago has been shaped by sea level change, ocean currents, and the onset and intensification of the South Asian Monsoon (SAM). The SAM is an intense climatic phenomenon that provides ample precipitation to southern Asia and is linked to a seasonal reversing wind pattern that controls the modern ocean circulation and productivity in the north and central Indian Ocean, as well as the development of the oxygen minimum zone (OMZ) in the water column. International Ocean Discovery Program (IODP) Expedition 359 drilled eight sites (U1465-U1472) in the carbonate edifice across the Maldives to reconstruct changes in sea level and ocean circulation, as well as monsoon evolution in this mostly unread archive of the Indian Ocean. Site U1467 was cored to 630 m below the sea floor in the Inner Sea at a water depth of 487 m. Because of its location in the center of The Maldives, the Inner Sea is a natural sediment trap. Cores recovered at this site yielded a continuous Miocene to Holocene sedimentary sequence with abundant and well-preserved calcareous microfossils, including ostracods. The focus of this study is to reconstruct glacial/interglacial changes in bottom water ventilation and circulation, and changes in the OMZ related to Monsoon dynamics throughout the Pleistocene by analyzing the deep-sea ostracod record at Site U1467. Ostracods will be compared and discussed within a multiproxy dataset including benthic foraminifera, alkenones, stable isotopes, sediment physical properties, and X-ray fluorescence spectrometry. Results show that ostracod variability reflects Pleistocene changes in sea-level, bottom water ventilation, and monsoon intensification in the northern Indian Ocean.
Year of Publication: 2017
Research Program: IODP Integrated Ocean Drilling Program
IODP2 International Ocean Discovery Program
Key Words: 02 Geochemistry; 24 Surficial Geology, Quaternary Geology; Alkenones; Arthropoda; Assemblages; Cenozoic; Crustacea; Expedition 359; Foraminifera; IODP Site U1467; Indian Ocean; Indian Ocean Islands; International Ocean Discovery Program; Isotopes; Ketones; Maldive Islands; Mandibulata; Marine environment; Microfossils; Organic compounds; Ostracoda; Paleo-oceanography; Paleoclimatology; Paleoenvironment; Pleistocene; Quaternary; Spectra; Stable isotopes; X-ray fluorescence spectra
Coordinates: N045101 N045103 E0731702 E0731701
Record ID: 2018059097
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data supplied by the Geological Society of America, Boulder, CO, United States