Magnetic characteristics of sediments from a radial sand ridge field in the South Yellow Sea, eastern China, and environmental implications during the mid- to late-Holocene

Indian summer monsoon variability over last 2000 years inferred from sediment magnetic characteristics in Lugu Lake, southwest China

“…Although the values of TOC (total organic carbon) and TN (total nitrogen) are lower between 1950 and 2012 CE, showing the increase in human activities decrease significantly. The previous studies have shown that the causes of heavy metal pollution were mainly from atmospheric metal deposition from anthropogenic sources (Lin et al, 2018;Wang et al, 2018aWang et al, , 2018b. We estimated that increase of magnetic mineral contents between 1950 and 2012 CE was caused by the atmospheric metal deposition rather than the local mining wastewater (Fig.…”

“…Based on the relationships of χ vs. χ fd % and χ vs. χ ARM /χ, the samples can be divided into three parts. The samples deposited between 1950 and 2012 CE were influenced by heavy metal pollution, which was caused by modern industrial activities (Lin et al, 2018;Wang et al, 2018aWang et al, , 2018b. Although the values of TOC (total organic carbon) and TN (total nitrogen) are lower between 1950 and 2012 CE, showing the increase in human activities decrease significantly.…”

“…Lugu Lake is fed hydrologically by rainfall, seasonal inflow, and surface runoff. The Gaizu River, which is the only outlet of Lugu Lake, is connected with the lake by the Caohai wetland (Wang et al, 2018a(Wang et al, , 2018b. The basin bedrock is mainly composed of sandstone, limestone, and mudstone.…”

“…Two components are separated: component 1 represents soft magnetic minerals (magnetite), while component 2 represents hard magnetic minerals (hematite). minerals (Ma et al, 2014;Wang et al, 2018aWang et al, , 2018b. Based on the relationships of χ vs. χ fd % and χ vs. χ ARM /χ, the samples can be divided into three parts.…”

“…The lakes in this area are tectonic lakes with fragile ecosystems, and can respond to environmental changes on scales from decades to millions of years (Chen et al, 2014;Wang et al, 2019). Magnetic measurement is a rapid, intensive, and non-destructive method to characterize high-resolution mineralogical changes, and is widely used in marine sequence comparison, paleoclimate, and provenance research (Peters et al, 2010;Chang et al, 2016;Wang et al, 2018aWang et al, , 2018b on lacustrine (Hu et al, 2015;Xu et al, 2020) and aeolian sediments (Gao et al, 2018). Magnetic mineralogy has become one of the most important proxies in paleoenvironmental and paleoclimatic reconstruction (Su et al, 2013;Lise-Pronovost et al, 2014).…”