TY  - JOUR
A1  - Ehlert, C.
A1  - Frank, M.
A1  - Haley, B. A.
A1  - Boeniger, Urs
A1  - De Deckker, P.
A1  - Gingele, F. X.
T1  - Current transport versus continental inputs in the eastern Indian Ocean  Radiogenic isotope signatures of clay size sediments
JF  - Geochemistry, geophysics, geosystems
N2  - Analyses of radiogenic neodymium (Nd), strontium (Sr), and lead (Pb) isotope compositions of clay-sized detrital sediments allow detailed tracing of source areas of sediment supply and present and past transport of particles by water masses in the eastern Indian Ocean. Isotope signatures in surface sediments range from -21.5 (epsilon Nd), 0.8299 ((87)Sr/(86S)r), and 19.89 ((206)Pb/(204)Pb) off northwest Australia to + 0.7 (epsilon Nd), 0.7069 ((87)Sr/(86)Sr), and 17.44 ((206)Pb/(204)Pb) southwest of Java. The radiogenic isotope signatures primarily reflect petrographic characteristics of the surrounding continental bedrocks but are also influenced by weathering-induced grain size effects of Pb and Sr isotope systems with superimposed features that are caused by current transport of clay-sized particles, as evidenced off Australia where a peculiar isotopic signature characterizes sediments underlying the southward flowing Leeuwin Current and the northward flowing West Australian Current (WAC). Gravity core FR10/95-GC17 off west Australia recorded a major isotopic change from Last Glacial Maximum values of -10 (epsilon Nd), 0.745 ((87S)r/(86)Sr), and 18.8 ((206)Pb/(204)Pb) to Holocene values of -22 (epsilon Nd), 0.8 ((87)Sr/(86)Sr), and 19.3 ((206)Pb/(204)Pb), which documents major climatically driven changes of the WAC and in local riverine particle supply from Australia during the past 20 kyr. In contrast, gravity core FR10/95-GC5 located below the present-day pathway of the Indonesian throughflow (ITF) shows a much smaller isotopic variability, indicating a relatively stable ITF hydrography over most of the past 92 kyr. Only the surface sediments differ significantly in their isotopic composition, indicating substantial changes in erosional sources attributed to a change of the current regime during the past 5 kyr.
KW  - Indonesian throughflow
KW  - Leeuwin Current
KW  - clay sediments
KW  - past circulation
KW  - radiogenic isotopes
KW  - weathering inputs
Y1  - 2011
U6  - https://doi.org/10.1029/2011GC003544
SN  - 1525-2027
VL  - 12
IS  - 12
PB  - American Geophysical Union
CY  - Washington
ER  -