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

developed under a joint venture agreement between the Kinross Gold Corporation of Canada and a consortium of Russian firms
under the Omolon Mining Company. The joint venture is the first Western and Russian mining venture to succeed in the Russian
Federation.
Alkalic gabbro
Korbin Formation, Coaly shale
(Lower Carboniferous)
Kubaka Sequence, trachy mj basaltic tuff, and trachyandesite
(Lower Carboniferous)
-1 Trachydacite
1 Rhyolite
-=.--
Tuffaceous sandstone ,
Rhyolite ignimbrite and tuff
(Devonian)
Biotite-amphibolite gneiss
(Archean)
Ore bodies
Fault
Thrust fault
Contact
10 Strike and dip of bedding
%
Figure 21. Kubaka Au-Ag epitherrnal vein deposit, Kedon rnetallogenic belt, Russian Northeast. Schematic geologic map and
oblique view cross sections. Adapted from I.N.Kotlyar and N.E. Sawa (written cornrn. 1994) and Sidorov and Goryachev (1994).
The stratified volcanic rocks and subvolcanic caldera rocks yield Rb-Sr isochron ages of are 332-344 Ma. Post-ore alkalic
basalt dikes exhibit K-Ar isotopic ages of 124- 155 Ma. Adularia from ore vein samples exhibit Ar-Ar ages which range from 110
to 175 Ma, with plateau ages ranging from 110-130 Ma. Cretaceous rhyolite and alkalic basalt dikes occur within and beyond the
mineralized tectonic block. Basalt dikes cross the mineralized veins and are themselves cut by later, Au-poor quartz-carbonate
veins and veinlets. The age of mineralization is interpreted as Late Devonian to Early Carboniferous because fragments of Au-
bearing calcedonic quartz occur in the adjacent conglomerates which contain Early-Middle Carboniferous fossils.
Olcha Au-Ag Epithermal Vein Deposit
The Olcha Au-Ag epithermal vein deposit (Zagruzina and Pokazaniev, 1975; Pokazaniev, 1976a, b; I.N. Kotlar, written
commun., 1984) consists of steeply dipping quartz, carbonate-quartz, and adularia-quartz veins and stockwork zones ranging from