Clay-mineral Formation in Soils Developed in the Weathering Zone of Pyrite-Bearing Schists: A Case Study from the Abandoned Pyrite Mine in Wieściszowice, Lower Silesia, SW Poland
Intense mineral transformations that produce acid soils from weathering zones of pyrite-bearing rocks, including alterations of layer silicates, are of critical importance to agricultural and environmental interests in various regions of the world. To date, the transformations of layer silicates in these soils have not been studied in detail. The aim of the present investigation was to examine the weathering pathways controlling processes of clay-mineral formation in acidic soils developed near the abandoned pyrite mine in Wieściszowice (Lower Silesia, SW Poland). A sequence of soils, from weakly developed technogenic soils (located on the mine dumps) to well developed natural soils, was selected. Bulk soil material and separated clay fractions were analyzed using X-ray diffractometry, Fourier-transform infrared spectroscopy, and scanning electron microscopy-energy dispersive spectrometry. The profiles analyzed were developed on pyrite-bearing schists containing trioctahedral Mg, Fe-chlorite and dioctahedral micas (muscovite and paragonite). Because of pyrite weathering, all the soils studied were strongly acidic (pH 2.8 À 4.4). Inherited chlorite and micas (K- and Na-mica) predominated in the clay fractions of soils developed on the mine dumps, whereas clays from natural soils were rich in pedogenic minerals (i.e. smectite, vermiculite, and mixed-layer minerals containing hydrated interlayers). The formation of both vermiculite and smectite at the expense of chlorite was observed in the soils studied. The transformation probably led to smectite formation via intermediate stages of mixed-layer minerals (i.e. chlorite-vermiculite, chlorite-smectite, and/or vermiculite-smectite). The process of chlorite dissolution took place simultaneously with the transformation. Micas were mainly transformed to smectite and mixed-layer mica-smectite. Neoformation of kaolinite occurring in A horizons of the soils investigated was also documented. Metal-hydroxy interlayers in Bw horizons of well developed soils were found. The process of interlayer development appeared to be pH dependent and took place at pH ≥ 4.2. The processes of clay-mineral formation in soils developed in the weathering zone of a pyrite-bearing schist are similar to those occurring in podzols (Spodosols).
No Supplementary Data
No Article Media
Document Type: Research Article
Publication date: December 1, 2011
More about this publication?
- The JOURNAL publishes articles of interest to the international community of clay scientists, including but not limited to areas in mineralogy, crystallography, geology, geochemistry, sedimentology, soil science, agronomy, physical chemistry, colloid chemistry, ceramics, petroleum engineering, foundry engineering, and soil mechanics. Clays and Clay Minerals exists to disseminate to its worldwide readership the most recent developments in all of these aspects of clay materials. Manuscripts are welcome from all countries.
Clays and Clay Minerals is the official publication of The Clay Minerals Society.
The Editor-in-Chief is Professor Joseph W. Stucki [email protected]
- Editorial Board
- Information for Authors
- Membership Information
- Annual Meeting of The Clay Minerals Society
- Ingenta Connect is not responsible for the content or availability of external websites