Fig 7 - uploaded by Nataliya Evgenievna Savva
Content may be subject to copyright.
Metasomatic changes in the host rocks of the Birkachan deposit. (a) Silicification, late veinlets of quartz; (b) quartz-carbonate alterations; (c) argillization and silicification (secondary quartz is overgrown with quartz lithoclastite; (d-e) contact of argillisites with alunite quartzites; (f) brecciation of vein quartz (quartz-hydromicaceous cement); (g) silicification of breccia with fragments of carbonaceous siltstone; (h) chlorite-carbonate metasomatite with dissemination of late pyrite; and (i) framelamellar texture of vein quartz.
Source publication
The Birkachan deposit in the Middle Paleozoic Kedonsky Volcanic Belt (KVB) is unique in Northeast Russia for its stockwork epithermal Au–Ag ores. The deposit is located in the northeastern part of the Gurnik volcanotectonic depression, in the Kedonsky segment of the KVB. The deposit is localized in the lying side of a large sublatitudinal thrust fa...
Contexts in source publication
Context 1
... zone no. 3 linear zones of argillisites and near-vein neoformations ( Natalenko et al., 2002). Almost all host rocks have undergone regional changes of propylite type: low-temperature carbonate-chlorite facies and, to a lesser extent, medium-temperature epidote-chlorite facies. (Fig. ...
Context 2
... 8a, 8b) form a linear sublatitudinal stockwork, in which ore zones are identified (Fig. 4). Pyrite is constantly present in the wall metasomatites accompanying ore veinlets (1-5%). Often, it has a zonal structure, which emphasizes the variability of the habit of crystals during growth: early, cuboctahedral (see below , Fig. 11i); late, cubic (Fig. 7h). (Table 1). The content of S common is very low (average, 0.16%), which corresponds to the poor sulfide nature of the revealed mineralization (see below), which is typical of epithermal Au-Ag ores of the KVB ( Volkov et al., ...
