FN Archimer Export Format
PT J
TI New insights into productivity and redox-controlled trace element (Ag, Cd, Re, and Mo) accumulation in a 55 kyr long sediment record from Guaymas Basin, Gulf of California
BT 
AF CHANG, Alice S.
   PICHEVIN, Laetitia
   PEDERSEN, Thomas F.
   GRAY, Victoria
   GANESHRAM, Raja
AS 1:1;2:2;3:1;4:1;5:2;
FF 1:;2:;3:;4:;5:;
C1 Univ Victoria, Sch Earth & Ocean Sci, Victoria, BC, Canada.
   Univ Edinburgh, Grant Inst, Sch Geosci, Edinburgh, Midlothian, Scotland.
C2 UNIV VICTORIA, CANADA
   UNIV EDINBURGH, UK
IF 3.433
TC 9
UR https://archimer.ifremer.fr/doc/00294/40566/39461.pdf
   https://archimer.ifremer.fr/doc/00294/40566/39462.doc
   https://archimer.ifremer.fr/doc/00294/40566/39463.pdf
LA English
DT Article
CR MD 126 / MONA
BO Marion Dufresne
DE ;productivity;redox;trace elements;laminated sediments;Guaymas Basin;northeast Pacific Ocean
AB A high-resolution, 55 kyr long record of chalcophile and redox-sensitive trace element accumulation (Ag, Cd, Re, and Mo) from MD02-2515, western Guaymas Basin, is investigated in conjunction with patterns in stratigraphy and productivity. High opal concentrations (~59 wt. %), representing increased diatom production, coincide with laminated sediments and dilute the concentrations of organic carbon (Corg) and metals. A similarity between opal and normalized Corg, Ag, and Cd concentrations suggests delivery to the sediments by diatom export production, while patterns in normalized Re and Mo accumulation suggest a different emplacement mechanism. Although Mo enrichment in organic-rich, laminated sediments typically represents anoxic conditions at other locations, Mo (and Re) in Guaymas Basin is enriched in nonlaminated and bioturbated sediments that are representative of oxygenated conditions. Adsorption onto Fe- and/or Mn-oxyhydroxide surfaces during oxygenation inadequately explains both the Re and Mo enrichments. Thus, recently published mechanisms invoking direct Re and Mo removal from the water column and bioturbation-assisted irrigation of Re into the sediments are used to explain the counterintuitive observations in Guaymas Basin. The MD02-2515 stratigraphic and proxy records are also different from other records in the northeast Pacific in that there is little correspondence with Greenland Dansgaard-Oeschger interstadials. There is some correlation with Heinrich events, suggesting that ventilation of intermediate waters and/or reduced productivity may be important in controlling stratigraphy and trace element accumulation. The results question whether MD02-2515 records can be compared to northeast Pacific open-margin records, especially before 17 kyr B.P.
PY 2015
PD FEB
SO Paleoceanography
SN 0883-8305
PU Amer Geophysical Union
VL 30
IS 2
UT 000351469300004
BP 77
EP 94
DI 10.1002/2014PA002681
ID 40566
ER

EF