Postsedimentation Alteration of Glauconite in Southeast Yakutia Riphean Beds

Gospodarka Surowcami Mineralnymi - Mineral Resources Management

“…The process of glauconite pyritization observed to the same extent in grains from the sand and sandstone, demonstrates that reduction conditions prevailed during sedimentation and diagenesis of the sediments, thus the environment of their formation was quite stable. Ivanovskaya et al (2010) pointed out that pyritization of glauconite was more intensive in the case of larger individuals (> 0.4 mm), which was also confirmed by the analyses performed (see fig. 4C).…”

“…These and the results of the studies of subsequent researchers (e.g. Hower 1961;Triplehorn 1966;foster 1951, 1969McRae 1972;Odin and Matter 1981;Odin and fullagar 1988;Amorosi et al 2007;Ospitali et al 2008;franus 2010;yakhontova 2010;Smaill 2015) showed that the individual glauconite grains differ with regard to the degree of crystallinity and structural maturity as well as to the composition of the swelling layers, and thus have a varied chemical composition.…”

“…In the initial stage of the transformations (glauconitization), the resulting folidoid is light green in color and its crystallinity increases with its maturity. It becomes richer in potassium and iron, which over time achieve significant dominance over aluminum and the color eventually becomes dark green (Shively and weyl 1951;warshaw 1957;yakhontova 2010). The exchange reactions lead to substitution in the tetrahedral layer of aluminum for silicon, and in the octahedral layer of iron and magnesium in place of aluminum.…”