Determining the influences of late Quaternary ventilation and productivity variations on Santa Barbara Basin sedimentary oxygenation; a multi-proxy approach

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doi: 10.1016/j.quascirev.2003.06.006
Author(s): Ivanochko, Tara S.; Pedersen, Thomas F.
Author Affiliation(s): Primary:
University of Edinburgh, School of GeoSciences, Edinburgh, United Kingdom
Other:
University of Victoria, Canada
Volume Title: Climate system history and dynamics; a Canadian program in earth system evolution
Volume Author(s): Peltier, W. Richard, editor
Source: Climate system history and dynamics; a Canadian program in earth system evolution, edited by W. Richard Peltier. Quaternary Science Reviews, 23(3-4), p.467-480. Publisher: Pergamon, Oxford, United Kingdom. ISSN: 0277-3791
Note: In English. 57 refs.; illus., incl. sketch map
Summary: A correlation between warm interstadials implied by δ18Oice in the GISP (Greenland) ice core and anoxic events recorded by the sediments drilled at ODP Site 893 in Santa Barbara Basin (SBB), has been used previously to relate variations in bottom water oxygenation to high-frequency changes in the ventilation of the SBB (Nature, 379 (1996) 243). However, an additional control on the oxygen content at depth is the local settling flux of metabolizable organic matter. To assess the impact of oxygen consumption related to this source, Mo, Cd, Re and U concentration data are used here in conjunction with % COrg and δ15N to deduce past redox conditions, variations in the sedimentary redox boundary depth and the impact of local organic flux on the oxygenation of SBB deep waters. Comparisons between ODP Sites 893, 1017 and 1019 allow the differentiation of regional signals, dominated by ventilation changes, from local signals, dominated by vertical organic flux. It is concluded that prior to the Holocene, local productivity changes in the Santa Barbara Basin are not solely the cause of sedimentary anoxia. Episodic injections of low oxygen intermediate water, identified on the regional scale, strongly influenced the oxygen content of the SBB during this time. However, over the last 10,000 years the influence of local productivity has increased and the regional similarity among the three sites is complicated by local signals. Abstract Copyright (2004) Elsevier, B.V.
Year of Publication: 2004
Research Program: ODP Ocean Drilling Program
Key Words: 02 Geochemistry; 24 Surficial Geology, Quaternary Geology; Actinides; Bolling; Cadmium; California; California Current; Cenozoic; East Pacific; Geochemistry; Holocene; Isotope ratios; Isotopes; Leg 146; Leg 167; Manganese; Marine environment; Marine sediments; Metals; Molybdenum; N-15/N-14; Nitrogen; North Pacific; Northeast Pacific; ODP Site 1017; ODP Site 1019; ODP Site 893; Ocean Drilling Program; Organic compounds; Oxygen; Pacific Ocean; Paleoclimatology; Paleoecology; Pleistocene; Productivity; Quaternary; Rhenium; Santa Barbara Basin; Sediments; Stable isotopes; Total organic carbon; United States; Upper Pleistocene; Upper Weichselian; Uranium; Weichselian; Younger Dryas
Coordinates: N414058 N414058 W1245559 W1245559
N341715 N343205 W1200211 W1210625
Record ID: 2005013889
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