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

Altinskoe, Aragochan, Dalnee, Dokhsun, and Verkhne-Naanchan, are associated with granitoid plutons. Isotopic studies indicate
the deposits and associated granitoid rocks formed from about 130-1 10 Ma (Nenashev, 1979; Goryachev, 1998.2003; Parfenov,
1995; Parfenov and others, 1999).
Polyarnoe Sn greisen and Vein Deposit
The Polyarnoe Sn greisen and vein deposit (Nekrasov, 1962; O.G. Epov and G.S. Sonin, written commun., 1964; Flerov,
1974) consists of quartz and quartz-topaz veins which dip gently to moderately (5-40') near and within a stock of apogranite at the
top of the major Cretaceous Omchikandin leucogranite batholith. The veins range from 0.1 to 3.5 m thick, are up to 300 m long,
and extend up to 260 m down-dip. The main minerals are quartz, topaz. fluorite, muscovite, zinnwaldite, wolframite. cassiterite,
arsenopyrite, molybdenite, tourmaline, sphalerite, galena, pyrite, chalcopyrite, stibnite, bismuth, bismuthine, and bismuth
sulfosalts. No size or grade data are available. The deposit is associated with quartz-topaz greisen.
Kandidatskoe Au Skarn Deposit
The Kandidatskoe Au skam deposit (Nekrasov, 1962; Bakharev and others, 1988) consists of zones of garnet-pyroxene,
pyroxene-wollastonite, pyroxene, and epidote-pyroxene skarn which range up to 100 to 150 m long and up to 50 m thick. The
skarn zones occur in a block of Devonian carbonate and Permian clastic rocks located between granodiorite of the Early
Cretaceous Ulakhan-Tass pluton and monzonite of the mid-Cretaceous Kandidatsky stock. The main (No. 1) ore body occurs as a
steeply-plunging, funnel-shaped pipe of massive and disseminated ore with an outcrop area of 150 m long and up to 20 m wide.
The main minerals are arsenopyrite, lollingite, pyrrhotite, molybdenite, glaucodot, cobaltite. gold, bismuth, bismuthine, maldonite,
hedleyite, and A and B joseite. The gold is fine-grained (98% less than 0.08 mm) and has a fineness of 650-1,000. At the adit level
(50 m), the thickness of the ore body is half of which at surface. The deposit contains up to 55 g/t Au, 3% Co, 20% As, 0.5% Bi,
3% Zn, 0.5%Ni, 0. 1% Te.
Chistoe Granitoid-Related Au Deposit
The Chistoe granitoid-related Au deposit (Bakharev and others, 1988) consists of a set of quartz veins which range from
10 to 50 m long and from 0.1 to 0.5 m thick. The veins occur in two steep-lying northeast-striking shear zones which range up to
500 m long and are hosted in contact metamorphosed Late Jurassic sandstone and in Early Cretaceous granodiorite stocks. The
main minerals are muscovite, quartz, tourmaline, arsenopyrite, cobaltite, calcite, wolframite, native bismuth, native gold (fineness
500-1000), bismuthine, joseite (A, B, M. L types), and maldonite. The veins are associated with greisen zones which range up to 1
to 2 m wide. The deposit contains up to 20 g/t Au, 0.9% W, 0.5% Bi, and 1% As.
Ilin-Tas Sn Silicate-Sulfide Vein Deposit
The Ilin-Tas Sn silicate-sulfide vein deposit (Shur and Flerov, 1979; T.N. Spomior and others, written commun., 1985)
consists of complex veins and less common shear zones and stringers which occur in contact metamorphosed Late Triassic
sandstone and siltstone adjacent to the Bezymyanny granitoid pluton. Granodiorite of the early magmatic phase has an Rb-Sr
isotopic age of 170 Ma with an initial Sr isotopic age of 0.7035, and fine-grained granite of the second phase has a Rb-Sr isotopic
age of 143 Ma with an initial Sr ratio of 0.0761 (Nenashev and others, 1985). The ore bodies dip steeply, range from 0.01 to 6 m
thick. and are about 100 m long. The veins are most dense at a distance of 500-1.000 m from the intrusive contact. The major
minerals are quartz, tourmaline, cassiterite, stannite, wolframite (ferberite), pyrrhotite, pyrite, arsenopyrite, and chalcopyrite. Also
occumng are Bi and Te minerals. The deposit is major with an average grade of 0.7-2.5% Sn; 0.3-1.0% WO,; up to 10 g/t Au.
Origin of and Tectonic Controls for
Yana-Polousnen Metallogenic Belt
The lode deposits of the Yana-Polousnen metallogenic belt are related mainly to the Early Cretaceous collisional
(anatectic) granitoid rocks of the Northern part of the Verkhoyansk granite belt (unit vk) (Nokleberg and others, 1994c, 1997c;
Goryachev, 1995, 1998,2003). The Northern part of this granite belt, which extends for about 600 km along northwestern margin
of the Kolyma-Omolon superterrane, consists of inclined sheet-like plutons, up to 200 km long, which are generally conformable
with major folds. Major lithologies are granodiorite, granite, and, less commonly, leucogranite. These granitoid rocks are
interpreted as forming immediately after the final, Early Cretaceous stage of accretion of the Kolyma-Omolon superterrane to the
North Asian Craton (Nokleberg and others, 2000).
Darpir Metallogenic Belt of Sn and
Associated Felsic-Magmatism Deposits
(Belt DP) Western Part of Russian Northeast
The Darpir metallogenic belt of Sn and associated felsic-magmatism-related deposits (fig. 61; tables 3,4) occurs in the
western part of the Russian Northeast. The belt is hosted in a zone of Early Cretaceous granitic intrusions which trends northwest