Deglacial climatic oscillations in the Gulf of California

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doi: 10.1029/PA005i006p01009
Author(s): Keigwin, L. D.; Jones, Glenn A.
Author Affiliation(s): Primary:
Woods Hole Oceanogr. Inst., Woods Hole, MA, United States
Volume Title: Special section; the Younger Dryas event
Volume Author(s): Kennett, J. P., editor
Source: Paleoceanography, 5(6), p.1009-1023; American Geophysical Union, 1989 fall meeting, symposium on the Younger Dryas event, San Francisco, CA, Dec. 4-8, 1989, edited by J. P. Kennett. Publisher: American Geophysical Union, Washington, DC, United States. ISSN: 0883-8305 CODEN: POCGEP
Note: In English. 67 refs.; illus. incl. 2 tables, sketch map
Summary: A high-resolution, accelerator radiocarbon dated climate record of the interval 8,000-18,000 years B.P. from Deep Sea Drilling Project site 480 (Guaymas Basin, Gulf of California) shows geochemical and lithological oscillations of oceanographic and climatic significance during deglaciation. Nonlaminated sediments are associated with cooler climatic conditions during the late glacial (up to 13,000 years B.P.), and from 10,300 to 10,800 years B.P., equivalent to the Younger Dryas event of the North Atlantic region. We propose that the changes from laminated (varved) to nonlaminated sediments resulted from increased oxygen content in Pacific intermediate waters during the glacial and the Younger Dryas episodes, and that the forcing for the latter event was global in scope. Prominent events of low δ18O are recorded in benthic foraminifera from 8,000 to 10,000 and at 12,000 years B.P.; evidence for an earlier event between 13,500 and 15,000 years B.P. is weaker. Maximum δ18O is found to have occurred 10,500, 13,500, and 15,000 years ago (and beyond). Oxygen isotopic variability most likely reflects changing temperature and salinity characteristics of Pacific waters of intermediate depth during deglaciation or environmental changes within the Gulf of California region. Several lines of evidence suggest that during deglaciation the climate of the American southwest was marked by increased precipitation that could have lowered salinity in the Gulf of California. Recent modelling studies show that cooling of the Gulf of Mexico due to glacial meltwater injection, which is believed to have occurred at least twice during deglaciation, would have resulted in increased precipitation with respect to evaporation in the American southwest during summertime. The timing of deglacial events in the Gulf of Mexico and the Gulf of California supports such an atmospheric teleconnection.
Year of Publication: 1990
Research Program: DSDP Deep Sea Drilling Project
IPOD International Phase of Ocean Drilling
Key Words: 03 Geochronology; 24 Surficial Geology, Quaternary Geology; Absolute age; Accelerator mass spectroscopy; Benthic taxa; Biochemistry; C-13/C-12; C-14; Carbon; Cenozoic; Cycles; DSDP Site 480; Dates; Deep Sea Drilling Project; Deglaciation; East Pacific; Foraminifera; Geochronology; Glacial geology; Glaciation; Globigerina; Globigerina bulloides; Globigerinacea; Globigerinidae; Guaymas Basin; Gulf of California; Holocene; IPOD; Invertebrata; Isotopes; Leg 64; Lower Holocene; Marine sediments; Mass spectroscopy; Microfossils; Neogloboquadrina; Neogloboquadrina dutertrei; North American Pacific; North Pacific; Northeast Pacific; O-18/O-16; Oxygen; Pacific Ocean; Paleo-oceanography; Paleoclimatology; Paleoecology; Planktonic taxa; Pleistocene; Protista; Quaternary; Radioactive isotopes; Rotaliina; Sedimentation rates; Sediments; Spectroscopy; Stable isotopes; Upper Pleistocene; Upper Weichselian; Weichselian; Younger Dryas
Coordinates: N275406 N275406 W1103921 W1103921
Record ID: 1991009270
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