Geochronological studies in Santa Barbara Basin: ⁵⁵Fe as a unique tracer for particulate settling

Abstract

Sediments accumulate in the Santa Barbara Basin relatively rapidly: about 3-4 mm yr^-1 based on the analysis of varves. These deposits are ideal for studying the applicability of nuclear geochronological techniques in a natural situation. Studies of the depth distribution of several radionuclides, manmade ⁵⁵Fe and naturally occurring ²¹⁰Pb and Th isotopes, in recent Santa Barbara sediment layers permit an evaluation of the geochemical behavior of Fe, Pb, and Th in coastal waters and have established the usefulness of ⁵⁵Fe and ²¹⁰Pb for dating coastial or near coastal sediments deposited during the last decade and half-century respectively.