SPECIFIC FEATURES OF GEOLOGIC STRUCTURE IN THE ERGELYAKH RARE-METAL,GOLD-ORE DEPOSIT

The Ergelyakh gold and rare-metal deposit is located somewhat aside of the gold-bearing belt of the Soviet Northeast and is distinguished from other deposits by many specific geological features. It lies near the northern boundary of a geoanticlinal structural unit, the Okhotsk residual massif, and is overlain by thin, calm-water deposits of the Verkhoyansk geosynclinal complex. The Ergelyakh deposit is confined to plutonic granitoid rocks, which are younger than the granitoid intrusions of the Upper Jurassic complex.

A combination of wolframite, scheelite, cobalt and nickel arsenides, younger gold-bearing bismuth tellurides and subordinate finely-dispersed native gold (low standard) is characteristic of the ore vein of this deposit and this is the most essential difference from the ore veins common for Soviet Northeast gold-quartz deposits. Search for deposits of the Ergelyakh deposit type is difficult since they are not accompanied by alluvial native-gold halos.—Auth. English summ.