THE CONCEPTUAL MODEL OF THE FORMATION OF THE UNIQUE SUKHOI LOG GOLD DEPOSIT BASED ON THE RESULTS OF A DETAILED GEOLOGICAL AND STRUCTURAL ANALYSIS
V.A. Vanin1,2, A.M. Mazukabzov1, A.E. Budyak2,3
1Institute of the Earth's Crust SB RAS, Irkutsk, Russia
2Irkutsk National Research Technical University, Irkutsk, Russia
3Vinogradov Institute of Geochemistry, Russian Academy of Science, Siberian Branch, Irkutsk, Russia
Keywords: Sukhoi Log deposit, layering, axial-plane cleavage, foliation, linearity, buckling fold, laminar current
Abstract
The article presents several published opposing points of view on the ore-controlling stage of the large (⁓ 2,000 t) Sukhoi Log gold deposit, as well as data from a detailed geological and structural analysis obtained by the authors. The deposit is located in the southern framing of the Siberian Craton in the black shale deposits of the Khomolkhin suite (610-600 Ma) on the territory of the Baikal-Patom folded belt. The complex regional structure of the Baikal-Patom belt formed as a result of the addition of the Baikal-Muya belt to the Siberian craton is demonstrated. The formation of industrial ores of the Sukhoi Log deposit and ore-controlling folding occurred in the Late Ordovician – Early Silurian (~ 450–420 Ma). The second stage of formation of weakly gold-bearing ores occurred in the early Carboniferous (340‒330 Ma). As a result of the conducted study, the absence of an ore-controlling fault zone of the syn-folded stage (450‒420 Ma) was established. It is shown that the internal structure of the gold ore zone is represented by intensively deformed rocks in the anticline core, where gold-quartz-pyrite veins occur in layers. It is concluded that the Sukhoi Log deposit is a classic example of disharmonious crumpling of plastic rocks in the core of an anticline, where signs of two stages of structure formation are combined: the longitudinal bending of a rock mass with the flow of matter and its (matter) laminar flow. Geological and structural studies of the deposit, together with previously published data, allow us to classify the deposit as an orogenic type, with a metamorphogenic-metasomatic of the redistribution of ore matter.
|
