Discussion on sedimentomorphic characteristics, material sources and their relationship with the environment based on the composition of soil in Xiong’an New Area

This paper is the result of environmental geological survey engineering.

Objective This paper aims to investigate the distribution characteristics, the contents and distribution of soil elements in different sedimentary geomorphic units of Quaternary, the control factors and the sources of sediment materials in Xiong’an New area, and to provide geochemical bases for the study of regional palaeogeographic evolution and epigenetic geochemical environments.

Methods Based on the surface element content data obtained from the geochemical survey and monitoring of land quality in Xiong’an New Area, this study employs multivariate statistical methods(such as elemental content analysis and ratio tracing) to reveal the relationship between regional elemental geochemical distribution patterns and the epigenetic environment.

Results The soil in the alluvial−lacustrine plain subregion has the characteristics of low value of SiO₂ and Na₂O, and high value of Al₂O₃、Fe₂O₃、MgO、CaO、K₂O and Na/Rb. The soil in the alluvial−diluvial plain subregion is characterized by high SiO₂ and Na₂O, and low Al₂O₃、Fe₂O₃ and Ca/Ba. The distribution of soil geochemical major elements is primarily controlled by chemical weathering intensity of source sediments, while epigenetic environment also influences the depletion and enrichment of major elements. The source area is currently in the stage of moderate chemical weathering dominated by plagioclase weathering, with no evidence of potassium metasomatism in weathering products. The soil parent materials in each sedimentary geomorphic unit are mainly derived from the mature continental quartz source of Taihang uplift on the west side of Xiong’an new district. Additionally, in the subregion of alluvial plain, parent materials of a small proportion of samples are from mafic volcanic and neutral igneous rocks.

Conclusions Geochemical indicators such as soil element contents, element ratios and element combinations (Rb−U−Ga, Fe−Mg−Ni−V) can effectively differentiate sedimentary geomorphic environments in the study area and serve as reliable tracers for soil parent material properties.