Fluorine and Chlorine Distribution in Sulphide and Low-Sulphide Platinum Ore Types of the Norilsk Deposits

There are two types of the Norilsk deposits platinum ores - sulphide and low-sulphide. The first are located at the bottom of layered intrusions and are presented by disseminated sulphides in picritic and lower taxitic gabbro-dolerites or massive sulphide ores. The second are situated at the intrusions top and are connected with horizon of upper taxitic gabbro-dolerites and leucogabbro. Both types of platinum ores are accompanied by increased amounts of biotite, calcium amphibole and apatite. It`s segregations gravitate to ore minerals. Middle concentrations of fluorine and chlorine (mas. %) in biotite are: in picritic gabbro-dolerites 0,7 and 0,13; in lower taxitic gabbro-dolerites 0,92 and 0,23; in upper taxitic gabbrodolerites 1,64 and 0,42; in leucogabbro 1,17 and 0,93. The micas of low-sulphide platinum ores have extreme concentrations (mas.%) fluorine - 5,23 and chlorine - 5,21. There are large oscillations of halogenes concentrations in apatites in limit one type of ores. Value fluorine and chlorine (mas. %) in apatite is: in picritic gabbro-dolerites 0,03 and 6,59; in lower taxitic gabbro-dolerites 0,03-2,45 and 0,34-6,88; in gabbro-dolerites relics of massive sulphide ores 2,2-2,5 and 0,06-2,02, in upper taxitic gabbro-dolerites 1,42 and 3,62; in graphitic leucogabbro 3,38 and 0,42. Graphite from leucogabbro is 9,45-10,35 mas.% of fluorine. Magnesian scarns apatite of platinum low-sulphide ores conteins (mas.%) fluorine - 2,22 and chlorine - 0,68. Concentrations of fluorine and chlorine (mas.%) in amphibole are composed: in picritic gabbro-dolerites - 0,24 and 0,18; in upper taxitic gabbro-dolerites - 0,24 and 0,17. Values of these components in chlorites from leocogabbro correspond to: 0,92 and 0,06 in brunsvigite; 1,15 and 1,19 in diabantite. The distribution of halogenes in biotites from sulphide and lowsulphide platinum ores in the series of rocks: picritic gabbro-dolerites - lower taxitic gabbro-dolerites – upper taxitic gabbro-dolerites - leucogabbro, points to that on

the measure of reducing a sulfur concentration in the ore forming fluids amount of F and Cl is increasing (accordingly 0,83-1,15-2,06-2,1 mas.%). It is accompanied with reducing part of F and increasing part of Cl. The change of F/Cl relation in specified number of rocks as 5,3-4,0-3,9-1,25 are indicated on this fact. The relation F/Cl from coexisting in one rock biotite-amphibole-apatite assotiations corresponds to 4,4-2,0- 3,4 in sulphide platinum ores and corresponds to 5,4-4,3-1,3 in low-sulphide platinum ores.