Sedimentary exhalative (Sedex) zinc-lead-silver deposit model. Mineral deposit models for resource assessment / Модель осадочно-испарительного месторождения (Sedex) цинк-свинец-серебро. Модели месторождений полезных ископаемых для оценки ресурсов

Sedimentary exhalative (sedex) deposits account for more than 50 percent of the world’s zinc (Zn) and lead (Pb) reserves (Tikkanen, 1986) and furnish more than 25 percent of the world’s current production of these two metals and a significant amount of silver (Ag) (Goodfellow and Lydon, 2007). More than 129 deposits of this type have been recognized in sedimentary basins around the world (Leach and others, 2005b; Goodfellow and Lydon, 2007). A compilation by Taylor and others (2009) shows that deposits occur in 25 sedimentary basins, 7 of which contain more than 10 million metric tons (Mt) of combined Pb+Zn (figs. 1, 2). In order of decreasing endowment, these basins are the Mt. IsaMcArthur basins, Australia (7 deposits containing 112 Mt of Zn+Pb metal); Selwyn basin, Canada (17 deposits, 55 Mt); Brooks Range, Alaska, United States (3 deposits, 40 Mt); Kholodninskoye deposit, Russia (1 deposit, 23 Mt); Rajasthan basin, India (5 deposits, 20 Mt); Belt-Purcell basin, United States and Canada (1 deposit, 19 Mt); and Rhenish basin, Germany (2 deposits, 11 Mt) (fig. 1). <...>