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

Origin of and Tectonic Controls for
Khamna River Metallogenic Belt
The carbonatites and alkalic igneous rocks of the Khamna River metallogenic belt intrude Late Proterozoic and early
Paleozoic sedimentary deposits of the folded margin of the North Asian Craton Margin (Shpikemn, 1998; Verkhoyansk fold
belt, unit NSV). U-Pb isotopic studies of the carbonatites and ores yield an age of 417 to 240 Ma, and K-Ar isotopic studies yield
an age of 350 to 280 Ma (Elyanov and Moralev, 1973). Because coeval, rift-relaled basaltic rocks formed in adjacent areas
neighboring areas, the Khamna River metallogenic belt is interpreted as forming during rifting of the North Asian Craton during
the Late Devonian to Early Mississippian. The sedimentary rocks of the Verkhoyansk fold belt are apparently tectonically
detached from crystalline basement of craton.. The fold belt is separated hm the Siberian platfm di a Late ~retacmusi west
verging thrust belt.
Sette-Daban Range Metallogenlc Belt of
Southeast Missouri Pb-Zn, Sediment-Hosted Cu,
and Basaltic Cu Deposits (Belt SD)
Southern Part of Eastern Siberia
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The Sette-Daban Range metallogenic belt of Southeast Missouri Pb-Zn, sediment-hosted Cu, and basaltic Cu &posits
(fig. 16; tables 3,4) occurs In the southern part of eastern Siberia (Nokleberg and others, IWc, 1997%; Shpikaman, 1998) in the
North Asian Craton Margin (Verkhoyansk fold belt, unit NSV). The metallogenic belt trends south to north for more than 700 km
along the Sette-Daban Mountain Range. The deposits, of Late Proterozoic to Early Carbonifmow age, occur at different
stratigraphic levels of the North Asian Craton Margin (Verkhoymsk fold belt, unit NSV). The major Southeast Missouri Pb-Zn
deposits are at Lugun, Sakyryr,, Segenyakh, and Urui; the major sediment-hosted Cu deposit is at Kurpn* and the major
basaltic Cu deposit is at Dzhalkan (table 4) (Nokleberg and others 3997a, b, 1998). The Southeast Missouri fb-Zn deposits are the
dominate deposit type in the metallogenic belt. The Southeast Missouri Pb-Zn deposits at Urui and Lugun occur in Vendian
dolomite of the Udom Formation and the Southeast Missouri Pb-Zn-fluorite occurrences at Segennyak and Sakyryr are hosted by
Late Silurian dolomite of the Oron Formation. The sediment-hosted Cu deposits are associated with basaltic Cu deposits which
usually occur at the same or nearby sh-atigraphic levels. The sediment-hosted Cu deposits are hosted in Late Devonian and Early
Carboniferous sandstone and shale.
Sardana Missouri Pb-Zn Deposit
The Sardana Missouri Pb-Zn deposit (ftg. 26) (Kuwetsov and Yanshin, 1979; Ruchkin and others, 1979; Kutyrev and
others, 1989) consists of disseminated, banded, massive, and breccia and ore and stringers which occur within and adjacent to a
dolomite bioherm which ranges from 50-80 m thick. The biahenn is hosted in the Late Proterozoic (Late Ymdian) dolomite of the
Yudom Formation. The ore bodies are lenticular, ribbon-like, and cylindrical in form, and are mostly conlhed to the overturned
limb of a syncline. The limb dips eastward at 75-85". The ore bodies range up to 40 m thick and are 200 to 300 m long at depth.
Drilling indicates additional ore bodies occur at a depth of 200 to 300 m. Most of the ore is associated with inetasomatic, sugar-
textured dolomite and zebra (brown and white striped) dolomite. The main ore minerals are sphalerite, galena, calcite, and
dolomite, and subordinate ore minerals are pyrite, marcasite, arsenopyrite, quartz, and anthraxolite. Oxidized ore minerals include
smithsonite, cerussite, anglesite, goethite, hydrogoethite, md aragonite. Low-grade disseminations m in Late Proterozoic (Late
Vendian) dolomite for many kilometers in both limbs, and in the axis of a north-south-trending synsline which b 3 km wide and
more than 10 km long. The deposit is medium to large with reserves of more than 1.0 million tomes PWZn, md a Pb:Zn ratio of
1 :3-4. The dolomite of Yudom Formation is 200 m thick and transgressively overlies Late Proterozoic (hte Riphean) quartz and
quartz-feldspar sandstone and siltstone which in turn is conformably overlain by Early Cambrian variegated clay and carbonate
rocks. The deposit intruded by sparse diabase and dolerite dikes.
Urui Southeast Missouri Pb-Zn Deposit
The Urui Southeast Missouri Pb-Zn deposit (Rucbkin and others, 1977; Volkodav and others. 1979; 8sgovh and others,
1979; N.D. Kobtseva and T.G. Devyatkina, written comrnun., 1988) consists of slralified ribbon-like @mi#, fPam 2-3 to 40 m
thick and 0.5 to 1.2 km long, which occur in metamorphosed Late Proterozoic (Vendian) doiomite. The ore bodies are
conformable to host rocks and strike 30-45"NW; and commonly wedge out at a depth of 3040 rn. The deposits vary from
massive, pocket-stringer-disseminated, to banded. Galena and sphalerite are the m ain ore minerals; pyrite, marcasite, menopyrite
are secondary; and pynhotite, chalcopyrite, and electrum are scarce. Calcite, quartz, and anthraxolite also occur. The deposit is
medium to large with an average grade of 9.9-25.6 Pb; 6.4-21.3% Zn; 6.8-200 glt Ag; up to I0 glt Oe. The deposit is associated
with a significant recrystallization of dolomite and formation of peculiar zebra dolomite rocks. The general struchlral pattern of
deposit controlled by monoclinal strike of sedimentary rocks to the west and by numerous postare faults which trend roughly
east-west and strike northwest. Local Paleozoic diabase dikes in area.
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