The relationship between environmental factors and magnetic susceptibility in the Ili loess, Tianshan Mountains, Central Asia

Abstract

The mechanisms of the magnetic susceptibility (MS) enhancement of loess from Arid Central Asia (ACA) have received much attention recently. Consensus varies about factors controlling the magnetic properties as well as the environmental implications, and much effort needs to be gone into how surface processes affect the MS. In this study, we collected 214 topsoil, near‐surface loess, and fluvial sediment samples covering different elevations, climatic conditions, and vegetation from the Ili Valley in eastern ACA and analysed their magnetic properties and composition to investigate the factors influencing MS. Redundancy analysis (RDA) was employed to assess the relationship between environmental indicators and environmental factors. Our results show that (a) the concentration of pedogenic magnetic particles in the Ili loess and topsoils is limited. χlf is higher in loess but lower in paleosol, mainly attributable to changes in wind intensity; (b) the mean χfd, χfd%, and χlf values of topsoil are lower in the desert steppe and forest–meadow zones, but highest in the montane steppe zone, and are not positively associated with vegetation coverage and the intensity of pedogenic processes; and (c) elevation exerts the most important impact on topsoil χfd and χfd%, while χlf is influenced more by temperature than precipitation. (d) The magnetic enhancement could be mainly attributed to wind velocity; we also should consider elevation and other factors such as local material, climatic conditions, and distance to the dust source when interpreting the paleoclimatic or paleoenvironmental significance of magnetic parameters.

A Combined Rock Magnetic and Meteorological Investigation of the Precipitation Boundary Across the Tibetan Plateau

“…Based on a synthesis of the rock magnetic and meteorological data, we define the relationship between pedogenic magnetite and/or maghemite content and precipitation. In addition, combined with previous research in the northern TP (Jia et al, 2013;Zan et al, 2020;Zeng et al, 2018), our findings provide a comprehensive picture of the spatial distribution of precipitation in the TP and its adjacent regions. The results further demonstrate the possibility of using soil magnetic properties to characterize the precipitation distribution across the TP and its adjacent areas, where no long-term climate records and meteorological stations exist.…”

Magnetic Response of Heavy Metal Pollution in Soil of Urban Street Greenbelts

“…SOFT mainly reveals the low coercivity magnetic particle content of multidomain and single domain boundary ranges, which closely reveals the concentration of magnetite [35]. The soil samples SOFT in the study area ranged from 588.75 ×10 -5 to 3577.86 ×10 -5 Am 2 /kg with average values of 1368.95 × 10 -5 Am 2 /kg.…”

Effect of chemical pretreatments on magnetic susceptibility of loess from Central Asia and the Chinese Loess Plateau

“…The experiments indicate that the process of loess MS enhancement in Central Asia differs from that on the CLP, consistent with other geochemical and magnetism investigations. [19][20][21]35,39,56,57 These results help in understanding the paleoclimatic signicance and paleoenvironmental reconstruction in the Central Asia arid area.…”