We analyzed selected minor and trace element contents to examine the sources and transport paths of sediments deposited at Ocean Drilling Program Site 1017 during the last 25 k.y. Elements are subsequently classified as being of diagenetic, biogenic, and/or terrigenous origins. Re, U, Mo, and As are diagenetically enriched within sediments, reflecting millennial-scale variability in bottom-water oxygenation and/or the sedimentary redox boundary depth. Sr variation is largely controlled by the input of biogenic carbonate. Using Q-mode factor analysis, variations in the 12 elements of detrital origin that remain can be explained by three factors (end-members) attributable to sand- and silt-sized detritus (Factor 2), and fine fractions with mafic (Factor 3) and felsic (Factor 1) characteristics. Elimination of the influence of grain size, temporal variations in the relative contribution from mafic materials shows that more detritus from the mafic Franciscan Complex was transported to the site during marine isotope Stage 2 than during the Holocene. This was probably due to enhanced southward littoral transport of detritus along the California margin during the latest Pleistocene.
1Lyle, M., Koizumi, I., Richter, C., and Moore, T.C., Jr. (Eds.), 2000. Proc. ODP, Sci. Results, 167 [Online]. Available from World Wide Web: <http://www-odp.tamu.edu/publications/167_SR/167sr.htm>. [Cited YYYY-MM-DD]
2Department of Earth and Planetary Sciences, Hokkaido University, Kita-10, Nishi-8, Kita-ku, Sapporo, 060-0810, Japan. (Present address: Marine Geology Department, Geological Survey of Japan,1-1-3 Higashi, Tsukuba, 305-8567, Japan. irino@gsj.go.jp)
3Oceanography, Earth and Ocean Sciences, University of British Columbia, 6270 University Boulevard, Vancouver, B.C. V6T 1Z4, Canada.
Date of
initial receipt: 21 October 1998
Date of acceptance: 10 May 1999
Ms 167SR-209