Platinum-group minerals in the O'Toole (Ni-Cu-Co) deposit, Brazil

SOBOLEVSKITE, TAIMYRITE, AND Pt2CuFe (TULAMEENITE?) IN COMPLEX MASSIVE TALNAKHITE ORE, NORIL'SK OREFIELD, RUSSIA

“…Polarite [Pd(Bi,Pb)] (Genkin et al 1969 Rudashevsky et al 1992], yet the extent of solid solution toward Pt end-members is unknown. In addition, evidence of a solid solution between Pd(Te,Bi) toward NiTe, in an undetermined crystal system, also has been presented (e.g., Cabri & Laflamme 1976, Marchetto 1990). …”

Sulfur Isotopes in Komatiite-Hosted Ni-Cu Sulfide Deposits from the Morro do Ferro Greenstone Belt, Southeastern Brazil

“…The nickel-copper-cobalt sulfide occurrence of the Morro do Ferro greenstone belt, called the O'Toole deposit in the recent literature (Brenner et al, 1990), consists of massive ore, disseminated ore, matrix ore, breccia, and stringer ores. Details of these ore types and their mineralogy have been described pre viously (Marchetto, 1990): the main sulfides are pyrrhotite (65%), pentlandite (30%), and chalcopyrite (5%).…”

“…The nickel orebody occurs at the base of the fourth cycle, at the contact of serpentinite with the underlying BIF; the lower three cycles are barren. The sulfide ore minerals are, in order of abundance, principally pyr rhotite, pentlandite, and chalcopyrite; plati num-group elements (PGE) associated with these sulfides have been recognized by Marchetto (1990). Silicate phases that occur with the pyrrhotite-pentlandite-chalcopyritemagnetite assemblage of the ores are tremolite, anthophyllite, cummingtonite, chlorite, late talc substituting for amphiboles, and occasional serpentine.…”

“…After a good many stud ies of greenstone belts in Brazil, attention was focused on the Morro do Ferro greenstone belt, and over the years investigators from univer sities as well as mining companies have been drawn to this region (Teixeira and Danni, 1979;Schmidt, 1983;Teixeira et al, 1986;Brenner et al, 1990). In addition, the occurrence of plati num-group elements proved to be of consider able interest, not only for their economic importance, but also for an understanding of the genesis of this type of ore deposit (Marchetto, 1990). Although there have been many studies of greenstone belts in Brazil (often related to mesothermal lode gold deposits), only a few have investigated the ori gin of sulfide ores.…”

Memória da mineralogia brasileira

“…O nome pseudo-rutilo (1966) (196s), feüohalotriquita (1969), coutinita (1980), coutinhira (1981), neodimita (1980, 1981) e heitorita (1991) foram int¡oduzidos sem justificação adequada e também sem aprovação pela CNMNM-IMA. Coutinita" coutinhita e neodimita foram oficialmente desacreditados (1999 (Jedwab 1995, Jedwab & cassedanne 1998 (55,4,54,5;41,4,40,5 7o)400nn¡ (55,7 ,54,5;42,0,40,55 þ42}ma (56,0,54,6;42,8,40,6 Vù1.åûnnt,(56,5,54,8;43,45,40'7 %)460nn¡ (56,8,54,9;43,8,40,8 7o) Hussak (1902Hussak ( , 1903Hussak ( ' 1906c Marchetto (1986Marchetto ( , 1990 A (53,2, 55,1: 40,6, 42,35 %)s60na 64,4, 56,4; 41'8, 43 '6 Vù580nm" (54,9, 56,8: 42,4, 44,2 %)589nm, (55,4, 57,3; 42,8, M'7 Vo)600twt (5 6,4, 58,1 ; 43,9, 4 5,6 o...…”