Formation model and prospects of the northern flank of the Mindyak deposit for gold-sulfide mineralization (Southern Urals)
As a result of detailed lithofacies, structural, tectonophysical, petrophysical and isotopic-geochemical investigations, a genetic model is suggested for the gold-sulfide Mindyak deposit located within the zone of the Main Uralian Fault in the northern Magnitogorsk Megazone. Indicating characteristics of this model that can be used for prediction purposes are as follows: 1) regional structural control : occurrence in an extensional strike-slip duplex and, within its limits, at a junction of a N-E-trending imbricate thrust with a submeridional tectonic zone; 2) local structural control: localization of mineralization in secondary shears and oblique faults of a dextral strike-slip zone formed in place of a thrust slice; 3) lithological control: concentration of gold mineralization in a slice of polymictic olistostrome with carbonaceous cherty shale cement enriched with syngenetic sulfide mineralization (pyrite concretions and globular pyrite dissemination), and also within of the olistostrome: in olistoliths and olistoplaques of diabases and basaltic breccias; 4) sources of ore material: magmatogenic (ore-forming fluids) and primarily metamorphic (ore components associated with the regeneration of syngenetic pyrite mineralization). A promising area for gold-sulfide mineralization has been selected in the northern flank of the deposit near the village of Amangildino. This area represents a junction of collision-stage faults: a N-E-trending thrust slice with a younger submeridional fault zone. The thrust slice is composed of polymictic olistostrome that consists of olistoliths and olistoplaques of diabases, limestones, serpentinites and carbonaceous cherty shale cement. The Sredny Log gold-sulfide ore occurrence is located in the structural junction.