Ar-40/Ar-39 geochronology of magmatic and metasomatic events in the Sora porphyry Cu-Mo ore cluster (Kuznetsk Alatau)

Ar-40/Ar-39 dating (23 determinations) has been carried out for magmatic an d ore-metasomatic processes in the Sera copper-molybdenum ore region. Forma tion of the large Sera porphyry Cu-Mo deposit related to the evolution of a n ore-bearing porphyry complex was preceded by long formation of multipulse granitoid magmatism, separate pulses of which were accompanied by the occu rrence of Cu-Mo-skarn mineralization and K-feldspathic metasomatites with d ispersed chalcopyrite and molybdenite. The total age range of endogenic eve nts in the regions is 481-356 Ma. The evolution of the ore-bearing porphyry complex and related ore-metasomatic processes proceeded in several stages. The major industrial porphyry Cu-Mo mineralization of the Sera deposit is related to the first porphyry stage (389-388 Ma BP). The occurrence of ore- bearing porphyries and ore-metasomatic formations was preceded by intrusion of pre-ore dikes (405-402 Ma BP). The same geochemical profile (Cu, Mo) of ore mineralizations formed at different stages of multipulse magmatism and the similar petrogeochemical compositions and low (Sr-87/Sr-86)(0) values of magmatites evidence their genesis in the same zone of magma formation.