Geochemical features of native gold of the Lower Myakit ore-placer node (Northeast of Russia). I.S. LITVINENKO, L.A. SHILINA

Abstract

Geochemical features of native gold of the Lower Myakit ore-placer node (Northeast of Russia). I.S. LITVINENKO (N.A. Shilo North-East Interdisciplinary Scientific Research Institute, FEB RAS, Magadan), L.A. SHILINA (Magadan Regional Museum of Local Lore, Magadan).

The article presents the results of X-ray spectral microanalyses of native gold from ore occurrences and associated placers in the Lower Myakit ore-placer node located in the eastern part of the Yana-Kolyma ore-bearing belt. In terms of the frequency of occurrence of impurity elements, the native gold is bismuth-cuprous-mercury-telluric gold. In terms of the concentration level, the determining typomorphic impurities are Bi, Te and Hg. In the bismuth-sulfotelluride type of ores, high fineness native gold separations prevail, with Fe, Cu and Bi impurities playing an indicator role. Characteristic for the sulfide-sulfoarsenide ore type are moderately lower fineness and medium fineness formations with higher grades of Pb, Se and Te. Lower and extremely lower fineness gold of the silver-polysulfide type of mineralization contains higher concentrations of Te, Sb, As and Zn. With distance from the ore-generating granite intrusion, bismuth and iron contents tend to lessen while silver, antimony, mercury, and tellurium grades in the ore native gold, tend to increase.