The Kis-Kuel Fe-Cu-Au±(Ag, Mo, Bi) deposit, Eastern Yakutia (Russia) – a link between Iron Oxide Copper-Gold and Intrusion Related Gold systems

Abstract

The Iron Oxide Copper-Gold (IOCG) deposit class includes a number of loosely related deposits with a pool of common characteristics. The Kis-Kuel intrusion-related IOCG deposit in Eastern Yakutia (Russia) with a wide range of mineral styles has a direct genetic link with a cooling intrusion during its formation. The IOCG and the Kis-Kuel have common features for this style - the abundance of iron oxides and low of sulfides. Magmatic contribution to the Kis-Kuel deposit is significant. Intrusive rocks range from diorite to granodiorite in composition. Rare-earth geochemical system of igneous rocks of the Kis-Kuel intrusive is characterized by behavior close to the CHArge-and-RAdius-Controlled CHARAC-system (26<Zr/Hf<46 и 24<Y/Ho<34) in which the Н/Ho – Zr/Hf ratios of the pair show a distribution close to chondrite (Zr/Hf – 36.6 and Y/Ho – 27.7). Minor deviations of the Kis-Kuel rocks from the CHARAC intervals indicate a unevolved magmatic system. Mineralization was discovered at the top of small Kis-Kuel pluton and includes several types of ore. Iron Oxide Copper-Gold and Cu-Au-porphyry ore breccia in hornfelsed aureole of intrusive grades FeOX – 13.58-63.24%; Cu – 0-3.57%; Au – 12.93-64.48 g/t; Ag – 2.7-830 g/t. Associated with IOCG, quartz-hematite-galena veins grade Ag – 22.4-3680 g/t; Cu – 0.014-0.534%; Pb – 0.1-81.63%. Arrays of sheeted auriferous quartz veins with arsenopyrite, native gold and bismuth and Ag-Bi sulphosalts grade: Au – 0.15-4.6 g/t; Ag – 20.6-196 g/t; Cu – 0.048-0.24%; Pb – 0.3-3.73%. This paper is devoted to a Kis-Kuel diorite-granodiorite related deposit in the Eastern Yakutia (Russia). It is regarded as Intrusion Related Gold Deposit (IRGD) with a main IOCG and minor Cu-Au-porphyry component of mineralization.