Isotope Correlations In Rocks And Ores Of Major Intrusions In The Norilsk District

He, Ar, S, and Cu isotope characteristics of the Norilsk-1, Talnakh, and Kharaelakh ore-rich intrusions have been found to diverge. The intrusions' isotope characteristics form regression lines with the Kharaelakh intrusion having the highest atmospheric contribution of Ar and the Norilsk-1-the least one: this correspond to a degree of interaction with the host-rock, believed to be a source of atmospheric Ar, though may relate to the intrusions occurrence depth. delta S-34 has been found to decrease at growth of m (He-3/He-4) with the highest proportion of mantle S and He revealed in the Norilsk-1 intrusion. delta S-34 versus delta Cu-65 demonstrates negative correlation suggesting probable Cu income from different sources rather than its isotope fractionation: in this instance the Kharaelakh ores are dominated by the crustal Cu, Ni isotopic compositions vary narrowly, displaying no pronounced correlation with He, Ar, S, and Cu isotopes, implying: (1) a single mantle source of Ni and its minute fractionation; (2) contamination of ore system and its fluids by S, Cu and noble gases from the host-rocks; (3) the revealed isotopic variations may be accounted for two or three sources of matter.