Минералогия (Dec 2018)
MINERAL COMPOSITION OF ORE CLASTS OF THE NOVY SHEMUR MASSIVE SULFIDE DEPOSIT, NORTH URALS
Abstract
The features of mineral composition are considered for clastic ores composing the main part of rich Cu-Zn ores of the Novy Shemur massive sulfide deposit, North Urals. Most abundant ore types include sulfide breccias, which are composed of pyrite and sphalerite clasts in chalcopyritesphalerite-pyrite matrix, and sulfide turbidites with rhythmic alternation of sphalerite and pyrite layers. The amount of newly formed pyrite, sphalerite and magnetite increases and the amount of clasts of primary ores decreases in a range from breccias to sandstones. In the same direction, the Zn, Cd, Ag, Pb and Ga contents increase, while the Cu, Au, As, Co, and Mn contents decrease. Index accessory minerals of sulfide breccias are electrum, utenbogaardite, tennantite (up to 3.52 wt. % Ag), Ag- and Se-galena (up to 1.7 wt. % Se) and enargite. The sulfide turbidites contain Ag-rich galena, magnetite, arsenopyrite, tetrahedrite, and cassiterite included in newly formed sulfides. The matrix of clastic ores is characterized by the presence of Ga-bearing chlorite, mica, epidote and albite (Ga2 O3 from 1.24 to 4.88 wt. %). Our data reflect the peculiarities of mineral composition of rich Cu-Zn ores of the deposit and explain their high and higher contents of elements.
