Manganese oxide accumulations associated with some soil structural pores .II. Composite coatings and translocation

The morphology and composition of some composite coatings-containing manganese oxide coatings and impregnations-that were associated with the structural pores in a black earth (Typic Pellustert) subsoil layer were examined using light microscopy, electron microscopy, and electron micro-analytical techniques. Detailed examination of composite coatings indicates, firstly, that subsurface coatings and impregnations of manganese oxides had been formed by the burial of surface accumulations of manganese oxides with coatings of other soil components, and secondly, that fine-textured soil material had been translocated and deposited in a form which was virtually indistinguishable from that of the soil matrix.

Manganese oxide accumulations associated with some soil structural pores .I. Morphology, composition and genesis

The morphology and composition of manganese oxide accumulations associated with the structural pores in a black earth (Typic Pellustert) subsoil layer were examined using light microscopy, electron microscopy, X-ray diffraction and electron micro-analytical techniques. Birnessite was identified as the crystalline manganese oxide phase. There were significant positive correlations between cobalt, calcium and manganese and a significant negative correlation between iron and manganese. It was most probable that both microbial oxidation and auto-oxidation of Mn2+ contributed to the formation of the manganese oxide accumulations in this soil.