黔西南喀斯特地区红色风化壳的物源及元素迁移特征

南方喀斯特地区广泛分布着大量的红色风化壳,其成因及形成机制目前还存在争议。本文以贵州黔西南布依族苗族自治州泥凼石林的两处红色风化壳剖面(ND和YK)为研究对象,来探讨风化剖面上覆红土的物源问题,并计算其主、微量元素及稀土元素的迁移规律,认为本研究两处风化壳上覆红土为下伏基岩原位风化形成的,而且两剖面土壤均继承各自基岩的地球化学特征,并由于pH、风化强度等因素的影响表现出了元素迁移特征上的差异性。

Material Sources and Element Migration Characteristics of Red Weathering Crusts in Southwestern Guizhou

Guizhou Plateau, the center of Southwest China karst, develops red weathering crusts widely, and the provenance and formation mechanism of these weathering crusts are still controversial. This paper studied migrations of major, trace and rare earth elements in two red soil profiles (ND and YK) over limestone at the muddy celestial forest in the Buyi and Miao Autonomous Prefecture, Southwest Guizhou, and discussed the provenance of the red soils. The results indicated that:(1) the overlying clays were formed by in-situ weathering of the underlying carbonate, (2) soils of the two profiles (ND and YK) showed similar geochemical characteristics of the bedrock, characteristics variation might be resulted from influences of pH and weathering intensity.