Composition of manganese nodules and manganese carbonates from Loch Fyne, Scotland

Occurrence and geochemical nature of phosphatic rocks and Mn-rich carbonate rocks in the Toyoman Series, Kitakami Mountains, Northeastern Japan.

“…The rocks with P205 content exceeding 7.8% (about 20% of modal apatite) are described as phosphatic by Cressman and Swanson (1964), whereas those containing one or two orders of magnitude of P205 content greater than normal sediments are called phosphatic by most writers (Pettijo hn, 1975 Fig. 3B-2).…”

“…On the other hand, manganoan carbonates are also formed in shallow and lacustrine sediments, where they are associated with ferromanganese oxides (Calvert and Price, 1970 ;Pederson and Price, 1982). These Mn-rich carbonates contain various amounts of Ca, Mg and Fe, and may be the products of precipitation under anoxic condition.…”

Petrographic and electron microprobe investigation of some deep- and shallow-water manganese nodules

“…This shows a marked depletion of Co, Ni, Cu, Mo, and Pb and a high Mn/Fe ratio compared with the Carlsberg Ridge nodule. A fuller account of the geochemistry oJ nodules from this region has been reported by Calvert & Price (1970).…”

Subsea mineral resources

“…Birnessite Na4Mn14O27 -H2O (Fleischer, 1980) apparently has somewhat similar properties (Burns and Burns, 1977). It is the nodules rich in todorokite and birnessite that are rich in nickel and copper and the other minor metals previously described as most abundant in the > 1-percent Ni+Cu type (Burns and Fuerstenau, 1966;Barnes, 1967;Cronan and Tooms, 1969;Tooms and others, 1969;Margolis and Burns, 1976;Piper and Williamson, 1977;Calvert and Price, 1977;Halbach and Ozkara, 1979;Usui, 1979;Piper and others, 1979;Cronan, 1980;Bischoff and others, 1981). It is also the todorokite-rich nodules that have a manganese-iron ratio greater than 1.5 (Margolis and Burns, 1976;Piper and Williamson, 1977;Calvert and Price, 1977;Halbach and Ozkara, 1979).…”

“…It is the nodules rich in todorokite and birnessite that are rich in nickel and copper and the other minor metals previously described as most abundant in the > 1-percent Ni+Cu type (Burns and Fuerstenau, 1966;Barnes, 1967;Cronan and Tooms, 1969;Tooms and others, 1969;Margolis and Burns, 1976;Piper and Williamson, 1977;Calvert and Price, 1977;Halbach and Ozkara, 1979;Usui, 1979;Piper and others, 1979;Cronan, 1980;Bischoff and others, 1981). It is also the todorokite-rich nodules that have a manganese-iron ratio greater than 1.5 (Margolis and Burns, 1976;Piper and Williamson, 1977;Calvert and Price, 1977;Halbach and Ozkara, 1979). On the basis of microprobe analyses of individual layers of todorokite and the AMnO2 (vernadite) phase (including the amorphous iron) in nodules from the north-central Pacific, Usui (1979) found several of the elements that he examined to be parti-tioned between the two phases by grade, such that concentrations of manganese greater than 30 percent, of both copper and nickel greater than 0.8 percent, of magnesium greater than 0.8 percent, of potassium greater than 0.6 percent, and of sodium greater than 0.5 percent are in the todorokite phase and concentrations below those values are mostly, if not entirely, in the vernadite phase.…”