Magnetic investigation of Late Quaternary loess deposition, Ili area, China

A Late Quaternary loess section in Ili river valley, Xinjiang, northwest China has been studied magnetically. Samples from two sections exhibit variations in magnetic susceptibility which displays a positive relationship with pedogenesis intensity in S0 and negative in S1 and L1. The detailed magnetic properties investigation reveals that concentration of initial magnetite and maghemite (FM) varies, and may be dominated by wind intensity and source mineralogy. Furthermore, this is the most important magnetic component influencing magnetic properties of loess/paleosol sequences, and controls magnetic properties of loess deposition. In contrast, concentration of pedogenic FM is low and has little influence on magnetic properties of loess. However, it is an ideal magnetic parameter to assess paleoclimate. The magnetic minerals in S1 soil units might be linked to reducing environments, reflected by the enhancement of the coercive force of remanence.