本研究调查了岩溶沟湿地中沉积物束缚的磁性和微量元素水平,草海国家级自然保护区,贵州省,中国。使用低频质量磁化率(χLF)对沉积物结合的磁信号进行定量,无磁滞剩磁磁化率(χARM),饱和等温剩余磁化强度(SIRM),和频率依赖性易感性百分比(χfd%)。Cd的浓度,Cr,使用电感耦合等离子体质谱法测定Sb和Zn。沉积物χLF,χARM,SIRM,χfd%高于基岩,主要受成岩过程影响。估计的χfd%范围为6.15%至14.62%,并且反映了磁性晶粒尺寸主要集中在超顺磁性粒子的范围内。沉积物结合的Cd浓度升高,Cr,Sb,锌和锌支持了人为源在喀斯特沟湿地中的重要贡献。磁信号与所选微量元素之间的弱关系(p<0.05)表明,与所选微量元素相关的沉积物结合的含铁矿物很少。这些结果表明,人为来源的某些微量元素对岩溶沟湿地中升高的沉积物磁信号的贡献很小。
This study investigated sediment-bound magnetic properties and selected trace elements level in the karst ditch wetland, Caohai National Nature Reserve, Guizhou Province, China. Sediment-bound magnetic signals were quantified using low-frequency mass magnetic susceptibility (χLF), anhysteretic remanent magnetization susceptibility (χARM), saturation isothermal remanent magnetization (SIRM), and percentage frequency-dependent susceptibility (χfd%). Concentrations of Cd, Cr, Sb and Zn were determined using inductively coupled plasma mass spectrometry. Sediment χLF, χARM, SIRM, and χfd% were higher than those of bedrocks and mainly altered by the pedogenic processes. The estimated χfd% ranged from 6.15 % to 14.62 % and reflected the magnetic grain sizes were largely concentrated in the range of superparamagnetic particles. The elevated concentrations of sediment-bound Cd, Cr, Sb, and Zn supported the significant contribution of the anthropogenic sources in the karst ditch wetlands. The weak relationship between magnetic signals and selected trace elements (p < 0.05) suggested the occurrence of few sediment-bound iron-containing minerals associated with selected trace elements. These results indicated that a minor contribution of anthropogenic sources of selected trace elements to the elevated sediment magnetic signals in the karst ditch wetlands.