Manzhi Chen , Xuexian Li , Xingxing Cao , Wentao Yang , Pan Wu , Haiyang Hao , Zhijun Fei , Yining Gao
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引用次数: 0
Abstract
Heavy metals (HMs) are often abnormally enriched in soils in geologically high background areas, posing a serious threat to the ecosystem and human health. However, the material origin of HMs in overlying soils is unclear. In this paper, we studied the accumulation control and formation process of HMs (Cd, Hg, As, Pb, Cr, Cu, Ni, and Zn) in soils overlying bedrock from different geological periods in a typical anticline structure area in southwest of Guizhou province. The results revealed that the content of HMs in the bedrock were ranked as Carboniferous carbonate rocks < Permian carbonate rocks < Triassic clastic rocks, while the opposite trend was observed for the HMs content in the overlying soil. The slopes of the EF-Q values of HMs in the soils overlying the Carboniferous, Permian, and Triassic rocks were 0.003, 0.007, and 0.83, respectively, which suggests that HMs enrichment or leaching was more complicated in the process of carbonate weathering soil-forming, whereas it was mainly in situ weathering during the process of clastic weathering soil-forming. The soils overlying the bedrock of the three geological periods experienced similar weathering processes and had the same source of soil-forming matrices, as it was observed that their Fe2O3-Al2O3, Hf-Zr, Nb-Ta, Th/Sc-Zr/Sc and Y/Ho-Y contents were significantly correlated (with R2 values of 0.80, 0.94, 0.72, 0.60, and 0.76, respectively) with very similar REE assignment patterns. The results corroborated the causes of the high background geological heterogeneity of HMs in the overlying soils in karst areas and supported the theory of the source of weathering soil-forming materials from carbonate rocks in karst areas.
重金属(HMs)经常在地质本底较高地区的土壤中异常富集,对生态系统和人类健康构成严重威胁。然而,上覆土壤中 HMs 的物质来源尚不清楚。本文研究了贵州省西南部典型反斜构造区不同地质时期基岩上覆土壤中 HMs(镉、汞、砷、铅、铬、铜、镍和锌)的累积控制和形成过程。结果表明,基岩中 HMs 的含量依次为石炭系碳酸盐岩、二叠系碳酸盐岩和三叠系碎屑岩,而上覆土壤中 HMs 的含量则呈相反趋势。石炭系、二叠系和三叠系岩石上覆土壤中 HMs 的 EF-Q 值斜率分别为 0.003、0.007 和 0.83,这表明碳酸盐风化成土过程中 HMs 富集或淋滤较为复杂,而碎屑岩风化成土过程中主要是原位风化。三个地质时期基岩上覆盖的土壤经历了相似的风化过程,成土基质来源相同,其Fe2O3-Al2O3、Hf-Zr、Nb-Ta、Th/Sc-Zr/Sc和Y/Ho-Y含量显著相关(R2值分别为0.80、0.94、0.72、0.60和0.76),REE赋存模式非常相似。结果证实了岩溶地区上覆土壤中 HMs 背景地质异质性较高的原因,支持了岩溶地区碳酸盐岩风化成土物质来源的理论。
期刊介绍:
Journal of Geochemical Exploration is mostly dedicated to publication of original studies in exploration and environmental geochemistry and related topics.
Contributions considered of prevalent interest for the journal include researches based on the application of innovative methods to:
define the genesis and the evolution of mineral deposits including transfer of elements in large-scale mineralized areas.
analyze complex systems at the boundaries between bio-geochemistry, metal transport and mineral accumulation.
evaluate effects of historical mining activities on the surface environment.
trace pollutant sources and define their fate and transport models in the near-surface and surface environments involving solid, fluid and aerial matrices.
assess and quantify natural and technogenic radioactivity in the environment.
determine geochemical anomalies and set baseline reference values using compositional data analysis, multivariate statistics and geo-spatial analysis.
assess the impacts of anthropogenic contamination on ecosystems and human health at local and regional scale to prioritize and classify risks through deterministic and stochastic approaches.
Papers dedicated to the presentation of newly developed methods in analytical geochemistry to be applied in the field or in laboratory are also within the topics of interest for the journal.