T76 Dating and Environmental Interpretation of Lake, Loess and Marine Sediment Sequences using Paleomagnetism and Rock Magnetism

Monday, 23 October 2006
8:00 AM - 12:00 PM

MINERAL MAGNETIC PARAMETERS AS PALEOENVIRONMENTAL PROXIES: A CASE STUDY USING ANNUALLY LAMINATED (VARVED) SEDIMENTS

Paper number: T76-13
Program: Technical Sessions
Time: 11:00 AM – 11:15 AM

Authors

Abstract

Mineral magnetic parameters have been used as indicators of increased soil erosion rates in numerous previous studies. Increased soil erosion may result from either anthropogenic activities (e.g. land clearance,cultivation) ,or naturally occuring paleoenvironmental changes (e.g. increased precipitation). We evaluate low-field susceptibility,ARM,IRM and ratios of these parameters as indicators of soil erosion. We compare stratigraphic profiles of these magnetic parameters to those of other paleoenvironmental proxies (e.g. varve thickness, GRAPE bulk density, CaCO3,and pollen). We find that mineral magnetic parameters are excellent indicators of anthropogenic activities. On the other hand, magnetic parameters need to be carefully calibrated on a site by site basis in order to be useful as indicators of climate induced changes in erosion rate.