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Recent allophane coatings from the karst and pseudokarst caves
Melka, Karel ; Cílek, Václav
Allophane is not often present in karst caves. As example of its occurence the Aragonite Cave near Ochtiná (Slovakia) can be set out. It was found there in an asbolane profile forming white earthy intercalations or is present in asbolane Mn ochre positions as the admixture. Allophane often occurs as coatings on the walls of abandoned ore mines. It can be also found in pseudokarst ice caves of the Podyjí National Park (the Ledové sluje Caves) in Moravia. The local aggregates form microcascades and flowstone-like structures in which allophane layers alternate with dark brown Al-Fe phosphates, sometimes with BaSo4 enriched laminate. Allophanes of these two localities were recognised by means of laboratory methods, especially electron microprobe analysis, X-ray powder diffraction and thermal analysis.
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