TY - JOUR T1 - Sediment Cd and Mo accumulation in the oxygen-minimum zone off western Baja California linked to global climate over the past 52 kyr JF - Paleoceanography Y1 - 2006 A1 - Dean, W. E. A1 - Zheng, Y. A1 - Ortiz, J. D. A1 - van Geen, A. KW - continental-margin KW - enhanced preservation KW - late pleistocene KW - marine-sediments KW - nitrogen isotope KW - northeast pacific waters KW - organic-carbon preservation KW - productivity variations KW - santa-barbara basin KW - suboxic sediments AB - [ 1] Concentrations of organic carbon (orgC), cadmium (Cd), and molybdenum (Mo) were measured in two sediment cores raised from depths of 430 and 700 m within the oxygen-minimum zone (OMZ) off southern Baja California at a temporal resolution of similar to 0.5 kyr over the past 52 kyr. These records are supplemented with diffuse spectral reflectance (DSR) measurements obtained on board ship soon after collection at a resolution of similar to 0.05 kyr. In the core from 700 m depth, a component extracted from the DSR data and the three geochemical proxies generally vary in concert with each other and over a wide range ( 4 - 22% orgC; 1 - 40 mg/kg Cd; 5 120 mg/kg Mo). Intervals of increased orgC, Cd, and Mo accumulation generally correspond to warm periods recorded in the oxygen-isotopic composition of Greenland ice, with the exception of the Bolling/Allerod which is only weakly expressed off Baja California. Concentrations of the biogenic proxies are higher in the core from 430 m depth, but erratic sediment accumulation before 15 ka precludes dating of the older intervals that are laminated and contain elevated orgC, Cd, and Mo concentrations. The new data provide further evidence of an intimate teleconnection between global climate and the intensity of the OMZ and/or productivity along the western margin of North America. On the basis of a comparison with Cd and Mo records collected elsewhere in the region, we conclude that productivity may actually have varied off southern Baja California by no more than a factor of 2 over the past 52 kyr. VL - 21 SN - 0883-8305 IS - 4 N1 - 110idTimes Cited:34 Cited References Count:68 JO - Paleoceanography ER - TY - JOUR T1 - Enhanced marine productivity off western North America during warm climate intervals of the past 52 kyr JF - Geology Y1 - 2004 A1 - Ortiz, J. D. A1 - O'Connell, S. A1 - DelViscio, J. A1 - Dean, W. E. A1 - Carriquiry, J. A1 - Marchitto, T. M. A1 - Zheng, Y. A1 - van Geen, A. VL - 32 IS - 6 N1 - id: 603 ER - TY - JOUR T1 - On the preservation of laminated sediments along the western margin of North America JF - Paleoceanography Y1 - 2003 A1 - van Geen, A. A1 - Zheng, Y. A1 - Bernhard, J. M. A1 - Cannariato, K. G. A1 - Carriquiry, J. A1 - Dean, W. E. A1 - Eakins, B. W. A1 - Ortiz, J. D. A1 - Pike, J. VL - 18 IS - 4 N1 - id: 1128 ER -