Features of placer gold indicating primary sources of the Au-Ag ore formation

Kazhenkina A. G., Nikiforova Z. S.

Zapiski RMO (Proceedings of the Russian Mineralogical Society). 2015. V. 144. N 3. P. 82-89

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Language: Russian

Abstract

Studied placer gold is represented mainly by the fraction >0.25—1.0—2.0 mm (60 %), laminated and clumpy shaped; flake-like particles 0.1—0.25 mm in size make another 40 %. Native gold has the medium or low fineness (from 500 to 870 ‰) with high admixture of Ag (up to 47.7 %) and Hg (up to 1.46 %). Internal structure of particles is mainly monocrystalline, with high-fineness inter-grain veinlets. Gold contains microinclusions of quartz, adularia, calcite, strontium barite, arsenopyrite and pyrite. In general, complex of features indicates that placer gold from the Lena-Viluy interfluve area (Kempendyai dislocation zone) is connected with the near-surface gold-silver ore mineralization linked paragenetically with andesite-dacite volcanism.

Key words: placer gold, indicating features, mineralogical-geochemical features, primary sources, gold-silver formation, Lena-Viluy interfluve area, Siberian platform