USGS Professional Paper 1697 - Alaska Resources Library

collision and regional thrusting, these rock units underwent
greenschist facies regional metamorphism with late-stage
formation of Au quartz vein deposits. Local higher-grade
metamorphism occurred in metamorphic domes.
Stanovoy Metallogenic Belt of Granitoid-Related
Au Deposits (Belt ST) Northern Part of the
Russian Southeast
The Stanovoy belt of granitoid-related Au deposits (fig.
61; tables 3, 4) occurs in northern part of the Russian Southeast
in the Stanovoy block of the North Asian Craton (unit
NSS) in the northwestern part of the Russian Southeast. The
granitoid-hosted Au deposits generally consist of quartz and
quartz-carbonate veins that are spatially associated with Jurassic
to Early Cretaceous granite and granodiorite that are generally
interpreted as forming in a collisional setting (Parfenov,
1995a,b; Nokleberg and others, 2001). The single, large
granitoid-related Au deposit in the belt is at Kirovskoe, a small
Au quartz vein deposit is at Zolotaya Gora, and Au-Ag epithermal
vein deposits are at Bamskoe and Burindinskoe (table 4)
(Nokleberg and others 1997a,b, 1998). Also occurring in the
area are numerous placer Au mines, as at Dzhalinda, Yannan,
and Ingagli Rivers, which constitute some of the largest placer
Au mines in the west-central part of the Russian Far East.
Kirovskoe Granitoid-Related Au Deposit
The Kirovskoe granitoid-related Au deposit (Gurov,
1969; G.P. Kovtonyuk, written commun., 1990) consists
northwest-striking Au-quartz-sulfide veins hosted in an Early
Cretaceous granodiorite stock. The veins occur mainly along
the contacts of diabase porphyry dikes that cut the granodiorite.
The contacts of veins are generally sharp, although host
rocks are hydrothermally altered. The veins are 0.5 to 1.0 m
thick, and the surrounding altered rock range from 5.0 to 9.0
m thick. The altered rocks consist mainly of quartz (40 to 95
percent), and albite, sericite, and hydromica. The main sulfide
minerals are pyrrhotite, arsenopyrite, and chalcopyrite along
with common galena, sphalerite, bismuthite, and tennantitetetrahedrite.
Fineness of gold ranges from 844 to 977. The
deposit is small, was mined until 1961, and about 10 tonnes
Au were produced.
Zolotaya Gora Au Quartz Vein Deposit
The Zolotaya Gora Au quartz vein deposit (Mel’nikov,
1984) consists of quartz veins and zones of hydrothermally
altered metamorphic rocks that occur conformably to host
rock layering. Alteration is predominantly sericite-quartz and
chlorite-amphibole-quartz. The main mineral assemblage is
sulfides-biotite-quartz, sulfide-sericite-quartz and biotitequartz-amphibole-chlorite.
Less common are amphibolequartz-feldspar
mineral assemblages. Four successive stages
of mineralization are identified—(1) magnetite-chalcopyritepyrrhotite-quartz,
(2) Au-carbonate-sulfide, (3) zeolite, and
Early Cretaceous Metallogenic Belts (144 to 120 Ma; figs. 61, 62) 145
(4) supergene. Gold occurs both in early and late quartz, and
in hydrothermally-altered rocks. Gold generally forms films
and fine plates in fractures and is concentrated in selvages of
quartz and quartz-pyrite veins. Gold fineness is high (985).
The deposit is small, has an average grade of grade 52 g/t Au,
and was intermittently mined from 1917 to 1948, and about
2.5 tonnes Au were produced. The deposit is hosted in gneissic
granite, granulite, calcareous shale, and quartzite of the Stanovoi
block of the North Asian Craton.
Burindinskoe Au-Ag Epithermal Vein Deposit
The Burindinskoe Au-Ag epithermal vein deposit (V.A.
Taranenko, written commun., 1991; G.P. Kovtonyuk, written
commun., 1993) occurs in steeply dipping quartz and quartzcarbonate
gold-bearing veins. The veins range as much as 200
m length, with an average thickness of about 10 m, and are
hosted in an Early Cretaceous volcanic sequence overlying the
Gonzhinsky terrane of the Burea-Khanka superterrane. The
deposit is small with an average grade of 9.5 g/t Au, 42.6 g/t
Ag. Ore reserves are about 827,400 tonnes with inferred 6,230
kg Au and 38,200 kg silver.
Origin of and Tectonic Controls for Stanovoy
Metallogenic Belt
The largest number of granitoid-related Au deposits and
related large placer deposits occur in the southern part of the
metallogenic belt, near a major fault between Precambrian
gneisses of the Stanovoy block to the north with the Paleozoic
rocks of the Tukuringra-Dzhagdi subduction-zone terrane
to the south (fig. 61). The latter is metamorphosed to greenschist
facies. The Paleozoic rocks contain beds of Au-bearing,
pyritized graphitic shale (V.I. Sukhov and others, written
commun., 1979). Because of these relations, the placer Au
mines and the associated granitoid-related Au deposits, mainly
Au-bearing veins and veinlets in collisional granitic intrusions
and adjacent metamorphic rocks (Gurov, 1978), are herein
interpreted as forming during the Late Jurassic and Early Cretaceous(?)
accretion of the Bureya superterrane to the south
with the North Asian Craton to the north and closure of the
Mongol-Okhotsk ocean (Nokleberg and others, 2000).
Metallogenic Belts Formed During Late
Mesozoic Accretion of Kolyma-Omolon
Superterrane in Russian Northeast
Kular Metallogenic Belt of Au Quartz Vein,
Granitoid-Related Au, and Sn Quartz Vein Deposits
(Belt KV), Northern Part of Eastern Siberia
The Kular metallogenic belt of Au quartz vein, granitoidrelated
Au, and Sn-W quartz vein deposits (fig. 61; tables 3,
4) occurs in the northern part of eastern Siberia. The belt may
extend under extensive Cenozoic deposits of the Primorskaya