L. B. MAKAR’EV, YU. B. MIRONOV, E. A. KUKHARENKO, L. N. SHARPENOK (VSEGEI)

Breccias formation in Mesozoic ultrapotassic alkaline rocks of the Murunsky magmatic cluster (Northern Transbaikal)

Detailed mineralogical-petrographic and geochemical studies of breccias in Mesozoic ultrapotassic alkaline rocks of the Murunsky magmatic cluster (Malomurunsky Massif) evidenced the existence of at least three groups of breccias, which corresponded to different stages of brecciation. The breccias are in general characterized by pronounced gold-polymetallic specialization; furthermore, there is sequential Au, Ag, Cu, Pb, Zn, Bi, Sb, Mo concentration from earlier to later derivatives with maximum accumulation (up to ore concentrations) in hydrothermal explosive breccias. The Malomurunskaya breccia pipe is promising for the detection of gold and complex mineralization and is assumed to be a mineralization environment that is non-traditional for the area.

Keywords: gold, base metals, breccias, ultrapotassic alkaline and calc-silicate syenites, Malomurunsky Massif