Yoo, Chanmin et al. (2004): Late Pleistocene paleoceanographic changes of the west Equatorial Pacific

Leg/Site/Hole:
ODP 138
ODP 138 847
Identifier:
2005-071772
georefid

Creator:
Yoo, Chanmin
Korea Ocean Research and Development Institute, Deep-Sea Resources Research Center, Seoul, South Korea
author

Hyeong, Kiseong
author

Kim, Ki-Hyune
author

Identification:
Late Pleistocene paleoceanographic changes of the west Equatorial Pacific
2004
In: Anonymous, Geological Society of America, 2004 annual meeting
Geological Society of America (GSA), Boulder, CO, United States
36
5
293
To delineate late Pleistocene paleoceanographic change of the West Pacific, we analyzed the oxygen and carbon isotopic ratios of two planktonic foraminifera species (G. sacculifer and N. dutertrei) from a piston core (KODOS-313) taken from the West Equatorial Pacific (02 degrees 00'N, 164 degrees 33'E), and they are compared with the published results of the East Pacific (ODP site 847 and RC 11-210), in terms of relative amounts and mass accumulation rates of CaCO (sub 3) and eolian component, back to marine isotopic stage (MIS) 6. Differences in oxygen and carbon isotope values between two foraminifera species (0.75 permil in delta (super 18) O, 0.05 permil in delta (super 13) C) are less than those of the East Pacific (1.30 permil in delta (super 18) O, 0.14 permil in delta (super 13) C), which indicates smaller vertical contrasts in both temperature and nutrient between mixing-zone and thermocline in the West Pacific. Strong deviation in delta (super 18) O of G. sacculifer from SPECMAP suggests the carbonate fraction of KODOS-313 was subjected to partial dissolution by bottom water under lysocline. Lower accumulation rates of CaCO (sub 3) and eolian component during glacial times are likely due to low sedimentation rate (ave. 0.75cm/1000 yr) combined with carbonate dissolution in KODOS-313 site. However, the high CaCO (sub 3) contents during the glacial periods clearly follow the general pattern of equatorial Pacific Oocean.
English
Coverage:Geographic coordinates:
North:0.1136
West:-95.1914East: -95.1911
South:0.1134

Quaternary geology; Isotope geochemistry; biochemistry; C-13/C-12; calcium carbonate; carbon; Cenozoic; East Pacific; Equatorial Pacific; Foraminifera; glacial environment; Globigerinacea; Globigerinidae; Globigerinoides; Globigerinoides sacculifer; Invertebrata; isotope ratios; isotopes; Leg 138; microfossils; mixing; Neogloboquadrina; Neogloboquadrina dutertrei; nutrients; O-18/O-16; Ocean Drilling Program; ODP Site 847; oxygen; Pacific Ocean; paleo-oceanography; paleotemperature; planktonic taxa; Pleistocene; Protista; Quaternary; Rotaliina; sedimentation; sedimentation rates; solution; stable isotopes; upper Pleistocene;

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