Mineralogical features of ore diagenites in the urals massive sulfide deposits, Russia
Maslennikov, VV and Ayupova, NR and Safina, NP and Tseluyko, AS and Melekestseva, IY and Large, RR and Herrington, RJ and Kotlyarov, VA and Blinov, IA and Maslennikova, SP and RR, Large, Mineralogical features of ore diagenites in the urals massive sulfide deposits, Russia, Minerals, 9, (3) pp. 1-38. ISSN 2075-163X (2019) [Refereed Article]
In weakly metamorphosed massive sulfide deposits of the Urals (Dergamysh, Yubileynoe, Yaman-Kasy, Molodezhnoe, Valentorskoe, Aleksandrinskoe, Saf'yanovskoe), banded sulfides (ore diagenites) are recognized as the products of seafloor supergene alteration (halmyrolysis) of fine-clastic sulfide sediments and further diagenesis leading to the formation of authigenic mineralization. The ore diagenites are subdivided into pyrrhotite-, chalcopyrite-, bornite-, sphalerite-, barite- and hematite-rich types. The relative contents of sphalerite-, bornite- and barite-rich facies increases in the progression from ultramafic (=Atlantic) to bimodal mafic (=Uralian) and bimodal felsic (=Baymak and Rudny Altay) types of massive sulfide deposits. The ore diagenites have lost primary features within the ore clasts and dominantly exhibit replacement and neo-formed nodular microtextures. The evolution of the mineralogy is dependent on the original primary composition, sizes and proportions of the hydrothermal ore clasts mixed with lithic serpentinite and hyaloclastic volcanic fragments together with carbonaceous and calcareous fragments. Each type of ore diagenite is characterized by specific rare mineral assemblages: Cu-Co-Ni sulfides are common in pyrrhotite-rich diagenites; tellurides and selenides in chalcopyrite-rich diagenites; minerals of the germanite group and Cu-Ag and Cu-Sn sulfides in bornite-rich diagenites; abundant galena and sulfosalts in barite- and sphalerite-rich diagenites and diverse tellurides characterize hematite-rich diagenites. Native gold in variable amounts is typical of all types of diagenites.
halmyrolysis, ore diagenite, enrichment, leaching, seafloor alteration and oxidation, rare mineral assemblages, massive sulfide deposits, the Urals