Metallogenesis and Tectonics of the Russian Far East, Alaska, and ...

which would be hosted in the early and middle Mesozoic Kmy-Mugal island-arc terrane. Additional isotopic mdka me needed.
The deposit is CI ~rrently being developed by Bslmo Gold Corpmriw and other parbwm.
F-4- VVV
mimm
Quartz-sulfide
cemented
75Q M
Figure 94. Karamken AU-Ag epithml veln deposrt, 0-k zone, Essm AsiaArciic metall- Wt, Russian Northeast.
Schematic cross sectlon showing genmliz8d geotogy of An'naMya volcanic stfuctwrre. Adapted by N.A. Shilyaeya, using
materials of R.B. Umitbaev, RA. Enamin, G.P. Dmin, and AA. Krmil'nikw, and from Sidorov and Gayachev and others (1M).
Agat Au-Ag Epitheml Yedn
The Agat Au-Ag +thermal vein c@dd (V.I. Nabrodin, wri#en coimaun., 1971,1977) cxm&a of m-1 tew, 8f
quartz, carbonate-quartz, and sulfidmprtz veins a ch wur in idwets of pmpylitically-altered Cretaceous andesite. The veins
are generally simple and an controlled by northwt- to north-south-trending fhurs. Tbe ore bodies usually range from tens to
hundreds of meters long, but somethes are up to 2 %m lung; tbcy av- from 0.2 to 1 m thick but are 50 m thick. The veins are
usually altered to hydromica, chlorite, and silicrr; however lcsg eroded veins -lay wed adularia alteration. The veins generally
display a symmetrical crustification-bding and m qdex &formation mctures. Thc main ore mhm& are galena, sphalerite,
chalcopyrite, marcasite, and pyrite. LocaIly present are wenopyrite, pynhotite, tetrahedrite-tennantite, tellurides, Ag-suLfosalts,
and other minerals. The main gangue mind are quartz and carhtes, kiuding calcite, doIomite, siderite, Mn-rich siderite,
rhodochrosite, and kutnahoritc. Barite, chaldony, and -1 occur mar ibe periphery of the deposit. Gold occurs as electnun. Tbe
veins average 5 to 10% sulfide, but locally ranges up to 20 to 30% sulfide. A gold-sphakitegalena-quartz assemblage is the most
productive, and is present in most vek. This assemblage elm cuntaiw Clmlwpyib, tetdakite-temmb, Au-und Ag-
590
260
0