Placer-forming properties of gold mineralization of the “Verny” site of the Degdekan deposits in the black-shale strata (Magadan Oblast)

Abstract

The placer-forming properties of vein-disseminated gold-sulfide-quartz mineralization in carbonaceous-terrigenous rocks of the North-East of Russia are considered on the example of the “Verny” site of the Degdekanskoe deposit, localized in the Permian black shale strata of the Ayan-Yuryakh antiktinorium of the Verkhoyansk-Chukotka folded region. According to the results of studies of the conditions for the presence of native gold in sample material crushed to 1 mm, it was established that the degree of release grains of gold in fractions of 0.1–0.25 and more than 0.25 mm from this type of ores with the given parameters of their physical destruction averages 33 and 75 %, respectively. This determines the relatively high placer-forming capacity of this type of primary sources. Calculation of the balance of native gold during the formation of a segment of placer Degdekan Creek, closely associated with the ore zones of the Verny site, showed its enormous placer-forming capabilities even under conditions of periglacial lithogenesis.