Rock-magnetic investigation of Siberia loess and its implication

Multiple-rock magnetic investigations conducted on the loess-paleosol seque nces at Kurtak in Southwestern Siberia reveal that the mass-normalized low- field magnetic susceptibility profiles reflect changes in lithology between relatively unweathered primary loess of glacial periods and the interglaci al paleosols. Maxima in susceptibility values correspond with the least-wea thered loess horizons, and minima with the humic horizons of soils. Frequen cy-dependent susceptibility of the loess-paleosol sequences at Kurtak is ve ry low and practically uniform, indicating the dominance of non-SP ferrimag netic minerals and negligible pedogenesis. The history of temperature-depen dence of susceptibility (TDS) and stepwise acquisition of the isothermal re manent magnetization (SIRM) have confirmed that magnetite is predominant ma gnetic mineral, and only few maghemite and probably hematite are present wi thin the studied section. Anisotropy of the magnetic susceptibility (AMS) c an be used to monitor tilt and disturbance of the sedimentary layers, and a lso to provide information about the paleo-transport direction for Siberia loess.