Paleoenvironmental implications of the magnetic characteristics of sediments from Deep Sea Drilling Project Site 514, Southeast Argentine Basin.

Abstract

Demonstrates the stratigraphic application of measurements of magnetic susceptibility and related parameters to the sediment record at Site 514. The work identifies two periods characterized by pronounced fluctuations in magnetic mineral concentration and in magnetic hardness: from 0-approx 0.75Ma (0-approx 10m sub-bottom) and from approx 2.6-3.0Ma (approx 60-90m sub-bottom). The fluctuations are tentatively ascribed to changes in current paleovelocity effecting periods of relative concentration of magnetic minerals. An attempt is made to express the susceptibility data in terms of an accumulation rate using the age-depth data available for the site. Changes in the intensity of Natural Remanent Magnetization (NRM) at the site are clearly shown to be controlled by changes in magnetic concentration and mineralogy rather than by changes in the intensity of the geomagnetic field.-from Author