“…The chemical composition of FM crusts from Lake Shotozero is as follows: iron zones (%): Fe (37-58), Mn (0-6), Ba (0), O (28-39), P (0.5-2), and total (72-100); manganese zones (%): Fe (0-3), Mn (33-55), Ba (1)(2)(3)(4)(5)(6)(7)(8), O (30)(31)(32)(33)(34)(35)(36)(37)(38)(39)(40)(41)(42), P (0), and total (56-99). The chemical composition of FM nodules from Lake Shotozero is as follows: granular zones (%): Fe (33-51), Mn (0-2), Ba (0), O (28-39), P (0.5-1), and total (61-96); manganese zones (%): Fe (0-20), Mn (33-56), Ba (1)(2)(3)(4)(5)(6)(7)(8), O (26)(27)(28)(29)(30)(31)(32)(33)(34)(35)(36), P (0), and total (60-99). Quite often, in the chemical composition of the FMC, the presence of Si, Al, Na, and Ca is determined in contents from 0.2% to 6%.…”