A 420,000-year record of cyclicity in oceanic and atmospheric processes from the eastern Equatorial Pacific

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doi: 10.1029/PA001i004p00577
Author(s): Rea, David K.; Chambers, Lucy W.; Chuey, John M.; Janecek, Thomas R.; Leinen, Margaret; Pisias, Nicklas G.
Author Affiliation(s): Primary:
Univ. Mich., Oceanogr. Program, Ann Arbor, MI, United States
Other:
Univ. Calif., Santa Cruz, United States
Lamont-Doherty Geol. Obs., United States
Univ. R.I., United States
Oreg. State Univ., United States
Volume Title: Special section; Milankovitch cycles through geologic time
Volume Author(s): Arthur, Michael A., editor; Garrison, Robert E.
Source: Paleoceanography, 1(4), p.577-586; Cyclic and periodic events in stratigraphy, evolution and the geologic record, Princeton, NJ, May 1985, edited by Michael A. Arthur and Robert E. Garrison. Publisher: American Geophysical Union, Washington, DC, United States. ISSN: 0883-8305 CODEN: POCGEP
Note: In English. 47 refs.; 4 tables, charts, sketch map
Summary: Samples from the upper portion of a cyclic pelagic carbonate sediment sequence in Deep-Sea Drilling Project (DSDP) hole 503B (4.0°N, 95.6°W) are the first group to be analyzed for paleoceanographic and paleoclimatic proxy-indicators of ice volume, deep ocean and surface water circulation, and atmospheric circulation in order to resolve the complex origin of the cyclicity. Temporal resolution is taken from the δ18O time scale, most other parameters are calculated in terms of their mass flux to the seafloor. CaCO3 percent in the sediments fluctuates in the well-known Pacific pattern and is higher during glacial times. The fluxes of opal and organic carbon have patterns similar to each other and show a variability of a factor of 2.5 to 4. The longer organic carbon record shows flux maxima during both glacial and interglacial times. The accumulation patterns of both opal and organic carbon suggest that the variability in surface water productivity and/or seafloor preservation of those materials is not simply correlated to glacial or interglacial periods. Eolian dust fluxes are greater during interglacial periods by factors of 2 to 5, indicating that eolian source regions in central and northern South America were more arid during interglacial periods. The record of eolian grain size provides a semiquantitative estimation of the intensity of the transporting winds. The eolian data suggest more intense atmospheric circulation during interglacial periods, opposite to the anticipated results. We interpret this observation as recording the southerly shift of the intertropical convergence zone to the latitude of hole 503B during glaciations.
Year of Publication: 1986
Research Program: DSDP Deep Sea Drilling Project
IPOD International Phase of Ocean Drilling
Key Words: 07 Marine Geology and Oceanography; 24 Surficial Geology, Quaternary Geology; Carbonate sediments; Cenozoic; Cycles; Cyclic processes; DSDP Site 503; Deep Sea Drilling Project; Distribution; East Pacific; East Pacific Rise; Environmental analysis; Equatorial Pacific; Grain size; IPOD; Isotopes; Leg 68; Marine environment; Marine sedimentation; Marine sediments; Milankovitch theory; O-18/O-16; Organic compounds; Organic materials; Oxygen; Pacific Ocean; Paleo-oceanography; Paleoatmosphere; Paleoclimatology; Pelagic environment; Quaternary; Sedimentation; Sediments; Stable isotopes; Stratigraphy; Textures; Upper Quaternary; Wind transport
Coordinates: N040303 N040303 W0953813 W0953813
Record ID: 1987037309
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