Internal structure and mineral composition of iron-manganese formations of the lake Bol'shoe Miassovo (the Southern Urals)

The internal structure of some ferromanganese formations from the lake Bol‘shoe Miassovo has been characterized. The data on their similarities and differences were given. The ferromanganese formations are were characterized by the presence of zonal structure and the substrate on which the productive part were growing. The main minerals were hydroxides (romanechite, hollandite, todorokite), carbonates (kutnohorite), barite.