USGS Professional Paper 1697 - Alaska Resources Library

192 Metallogenesis and Tectonics of the Russian Far East, Alaska, and the Canadian Cordillera
assemblage rich with galena, sphalerite, and chalcopyrite.
The host igneous rocks are spatially related to volcanic vents
of Paleocene age with K-Ar isotopic ages of about 65 Ma.
The deposit is small. Average grades are 0.1 to 2.17 percent
Cu, 0.03 to 1.02 percent Pb, 7.3 percent Sn, and 0.7 to 2.22
percent Zn.
Also in the same area are younger, generally uneconomic
Sn greisen occurrences with K-Ar isotopic ages of 60
to 50 Ma. In addition to Sn deposits, the northern part of the
Luzhkinsky metallogenic belt includes sparse small porphyry
Cu deposits, as at Verkhnezolotoe, which are associated with
Senomanian and Turonian monzodiorite in the northwestern
part of the belt near the Samarka accretionary-wedge terrane,
which contains abundant oceanic lithologies. The porphyry
Cu deposits are coeval with the Sn deposits of the Luzhkinsky
metallogenic belt, but presumably reflect the anomalous Curich
characteristics of the oceanic Samarka terrane.
Flysch deposits
(Early Cretaceous)
Conglomerate
Rhyolite breccia pipe
(Late Cretaceous)
Granite porphyry dike
(Late Cretaceous)
Basalt and rhyolite
dike (Paleocene)
0 100 200 300 m
Sn vein
Fault
Breccia
zone
Paleocaldera
boundary
Contact
Figure 92. Arsenyevskoe Sn silicate-sulfide vein deposit,
Luzhkinsky metallogenic belt, Russian Southeast. Schematic
geologic map. Adapted from Ratkin (1995). See figure 79 and
table 4 for location.
Origin of and Tectonic Controls for Luzhkinsky
Metallogenic Belt
The Luzhkinsky metallogenic belt hosts the Kavalerovo
ore district that has produced about 30 percent of the tin mined
in the former USSR (Gonevchuk and Kokorin, 1998). The
belt is interpreted as forming in the back-arc part of the East
Sikhote-Alin volcanic plutonic belt, which forms a major
continental-margin arc in the Russian Southeast.
The Cretaceous granitoid rocks hosting the Luzhkinsky
metallogenic belt are part of the East Sikhote-Alin volcanicplutonic
belt (fig. 79) of Late Cretaceous and early Tertiary
age (Gonevchuk and Kokorin, 1998) that is described in the
above section the origin of the Taukha metallogenic belt.
Other related, coeval metallogenic belts hosted in the East-
Sikhote-Aline volcanic belt are the Kema (KM), Lower Amur,
Sergeevka (SG), and Taukha (TK) belts (fig. 79; table 3). The
differences between the coeval metallogenic belts are interpreted
as the result the igneous rocks that host these metallogenic
belts intruding different bedrock. In contrast, to the
nearby Kema metallogenic belt, the Luzhkinsky metallogenic
belt occurs in the part of the East Sikhote-Alin igneous belt
that intrudes the southern part of the Zuravlevksk-Tumnin
turbidite basin terrane (fig. 79) (Nokleberg and others, 1994c,
1997c). Additional possible controls for the Luzhkinsky
metallogenic belt are (1) the turbidite deposits in the Zuravlevksk-Tumnin
terrane, which are enriched in Sn, and (2) the
Luzhinsky belt, which occurs in the back-arc part of the East
Sikhote-Alin igneous belt in that magnetite-series granitoid
rocks predominate.
Lower Amur Metallogenic Belt of Au-Ag Epithermal
Vein, Porphyry Cu, and Sn Greisen Deposits
(Belt LA), Northern Part of Russian Southeast
The Lower Amur metallogenic belt of Au-Ag epithermal
vein, porphyry Cu, and Sn Greisen deposits (fig. 79; tables 3,
4) occurs in the northern part of the Russian Southeast. The
deposits in the metallogenic belt are hosted in or near mid- and
Late Cretaceous and early Tertiary granitoid igneous rocks of
the East Sikhote-Alin volcanic-plutonic belt that intrude or
overlie the Amur River and Kiselyovka-Manoma accretionarywedge
terranes. The major Au-Ag epithermal vein deposits
are at Belaya Gora, Bukhtyanskoe, and Mnogovershinnoe; a
porphyry Cu deposit is at Tyrskoe, and a Sn greisen deposit is
at Bichinskoe (table 4) (Nokleberg and others 1997a,b, 1998).
The Au-Ag epithermal vein deposits, as at Mnogovershinnoe,
range from medium to large size and are generally
hosted in Paleocene alkaline granitoid rocks that are closely
associated with coeval andesite to dacite volcanic rocks.
Some Au-Ag epithermal vein deposits are associated with
Eocene and Oligocene volcanism (Khomich and others, 1989).
The Au-Ag epithermal vein deposits, as at Belaya Gora and
Bukhtyanskoe, are closely associated with rhyolite and trachyrhyolite
flows and vent rocks that are commonly hydro-