The application of high resolution IRM acquisition to the discrimination of remanence carriers in Chinese loess

Summary High resolution isothermal remanent magnetisation (IRM) acquisition was performed on forty-one Chinese loess samples with the aim of investigating the effects of weathering on the remanence carrying mineralogy. Magnetic susceptibility was taken as a measure of the degree of weathering. This is a valid assumption based on previous studies which have demonstrated a close relationship between climate and magnetic susceptibility in the Chinese loess. Detailed analysis, based on fitting accumulative log-gaussian curves to IRM acquisition data, reveals up to four distinct coercivity components. The remanences of the two harder coercivity components are found to be almost independent of magnetic susceptibility. On the other hand, the remanences of the two softer coercivity components are found to be positively correlated with magnetic susceptibility. Most probably the two harder components are associated with detrital iron-oxides in the primary dustfall, whereas the softer components were created during pedogenesis.