Environmental magnetic comparisons between distal and proximal sediments of Huangqihai Lake,Inner Mongolia,China

Spatial variations in lake sediments are a product of their depositional heterogeneities.To better correlate synchronous strata in Huangqihai Lake,two sections were excavated from the lake-center and the lake-shore.The study involved detailed lithology,mineralogy,and rock magnetic analysis.The results show that the frequency-dependent susceptibility,which is related to the content of super-paramagnetic minerals,is relatively easy to contrast between the two sections.However,mass susceptibility and saturation isothermal remanence,which are related to the content of total magnetic minerals,are difficult to contrast.A possible reason for this difference is that small-particle super-paramagnetic minerals are formed mainly during pedogenic processes,which correlates well with climate change and avoids the effects of local factors when corrections are made at the whole-lake scale.Both sections can be divided into three stages,which appear to be well correlated with previous results obtained through other environmental proxies.