PROVENANCE OF SAND DEPOSITED IN THE SANTA BARBARA BASIN AT SITE 893 DURING THE LAST 155,000 YEARS

Kathleen M. Marsaglia, Karl C. Rimkus, and Richard J. Behl

ABSTRACT

Sand layers recovered at Ocean Drilling Program Site 893 in the Santa Barbara Basin were sampled and petrographically analyzed to determine their provenance. Sand deposited at this site is quartzo-feldspathic with a minor lithic component. Plagioclase feldspar dominates over potassium feldspar, and sedimentary and metamorphic lithic fragments are more common than volcanic lithic fragments. Sand detrital modes are consistent with a source along the eastern flank of the Santa Barbara Basin, most probably a combination of the Santa Clara and Ventura rivers. Compositional trends observed within the thickest subunit (1C) can be explained in part by the lengthening of the Santa Clara River channel and the merging of the Santa Clara and Ventura river drainages with falling sea level.

Date of initial receipt: 1 September 1994
Date of acceptance: 19 January 1995


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