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

Like the Kema and Luzhkinsky metallogenic belts, the coeval Taukha metallogenic belt is hosted by East Sikhote-Alin
volcanic-plutonic belt of Late Cretaceous and early Tertiary age (fig. 79) which 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,
Luzhkinsky, Lower Amur, and Sergeevka (SG) belts (fig. 79; table 3). The differences between the coeval metallogenic belts are
interpreted as due to the host igneous rocks intruding different bedrock. The Taukha metallogenic belt contains mainly B skarn,
Pb-Zn skarn, and Pb-Zn polymetallic vein deposits, and is hosted in or near igneous rocks of the East Sikhote-Alin belt which
intrude the Taukha accretionary-wedge terrane which contains a complex assemblage of abundant Paleozoic and early Mesozoic
oceanic rocks and lesser Jurassic and Early Cretaceous turbidite deposits. In contrast, the Luzhkinsky metallogenic belt contains
mainly Sn greisen and Sn polymetallic vein, and porphyry Sn deposits, and is hosted in or near granitoid rocks of the East
Sikhote-Alin belt which intrude the Zuravlevksk-Tumnin turbidite basin terrane which contains mainly Late Jurassic and Early
Cretaceous turbidite deposits.
Kema Metallogenic Belt of
Ag-AU Epithermal Vein, and
Porphyry Cu-Mo Deposits (Belt KM)
Eastern Part of Russian Southeast
The Kema metallogenic belt of Ag-Au epithermal vein and porphyry Cu-Mo deposits (fig. 79; tables 3,4) occurs in the
eastern part of the Russian Southeast. The deposits in the metallogenic belt are hosted in or near Late Cretaceous and early
Tertiary granitoid rocks of the East Sikhote-Alin volcanic-plutonic belt which intrude or overlie the Kema island-arc terrane
(Nokleberg and others, 1994c, 1997~).
The major Au-Ag epithermal vein deposits in the Kema metallogenic belt are at Burmatovskoe, Glinyanoe, Salyut,
Sukhoe, Tayozhnoe, Verkhnezolotoe, and Yagodnoe (table 4) (Nokleberg and others 1997a, b, 1998). Porphyry Cu deposits are at
Nesterovskoe and Nochnoe, porphyry Cu-Mo deposits are at Sukhoi Creek, and a porphyry Mo deposit is at Moinskoe. The Ag
epithermal vein deposits, as at Tayoznoe, also occur in Early Cretaceous clastic and volcaniclastic rocks and in overlying Late
Cretaceous and Paleogene, subalkalic, postaccretionary volcanic rocks of the East Sikhote-Alin igneous belt. Ag sulfosalt minerals
predominate in the deposits. Concentrations of Ag are much greater than Au, and Ag/Au ratios generally are greater than 25 to 30.
Rare Pb-Zn polymetallic vein deposits occur in the metallogenic belt, but are not economic (P.1. Logvenchev, O.L. Sveshnikova,
and V.A. Pakhomova, written commun., 1994; Pakhomova and others, 1997). However, these deposits are generally of little
commercial value at the present. The epithermal vein deposits generally occur mostly in or near Danian (early Paleocene) and
Paleocene volcanic rocks; however, a few occur in granodiorite plutons (Khomich and others, 1989).
Porphyry Cu-Mo deposits in the Kema metallogenic belt occur mainly in the northern part of the belt at Moinskoe,
Nochnoe, and Sukhoi Creek. These deposits generally consist of disseminations and veinlets in and near the intrusive rocks and
coeval volcanic rocks which often contain notable amounts of Pb, Zn, W, Au, and Ag in addition to Cu and Mo. The deposits
occur in Late Cretaceous to Paleogene granitic and diorite intrusions. A porphyry Cu deposit occurs in the southern part of the belt
at Nesterovskoe. In the western part of the belt, in the eastern part of the adjacent Luzhkinsky terrane, are porphyry Sn deposits, as
at Mopau.
Glinyanoe Ag Epithermal Vein Deposit
The rich Glinyanoe Ag epithermal vein deposit (A.N. Rodionov, written commun., 1986) consists of adularia-quartz,
sericite-chlorite-quartz, and carbonate-chlorite-quartz mineralized veins and zones which contain pyrite, arsenopyrite, galena,
sphalerite, chalcopyrite, argentite, acanthite, Ag-tellurides, and native gold and silver. The veins and zones occur in altered,
silicified volcanic rocks which overlie Late Cretaceous (Santonian) felsic volcanic rocks. The deposit is interpreted to have
occurred in four stages: (1) gold-pyrite-quartz; (2) quartz-hydromica and quartz-carbonate; (3) gold-silver; and (4) quartz-chlorite-
adularia with Ag-sulfosalts. The age of the deposit is interpreted as Late Cretaceous to Paleogene. The deposit is judged to be
small. Average grades are 8.3 g/t Au and 122 g/t Ag.
Sukhoi Creek Porphyry Cu-Mo Deposit
The Sukhoi Creek porphyry Cu-Mo deposit (Petrachenko and others, 1988) consists of stockworks which reach several
hundred m across, and in altered zones. Polymetallic ore dominates in some stocks. The ore minerals are chalcopyrite,
molybdenite, sphalerite, galena, cassiterite, scheelite, and pyrite; with significant Au and Ag contents. The deposit occurs in Early
Cretaceous sedimentary rocks which are overlain by Late Cretaceous volcanic rocks and are crosscut by ore-bearing granitic
intrusions with a K-Ar isotopic age of 73 Ma. The Porphyry Mo mineralization is related to several granodiorite and granite stocks
which are intensely hydrothermally altered. Quartz-sericite alteration and medium-temperature epidote-prehnite-chlorite propylitic
alteration occur at the core and grade into micaceous-chlorite-carbonate propylite at the periphery. The granite is locally altered to
quartz-muscovite greisen with tourmaline and sphene, and in a few places into a peculiar garnet-phlogopite rock with apatite. The
host siltstone and sandstone are altered to orthoclase-actinolite-chlorite hornfels and the felsic extrusive rocks are altered to quartz
and phyllite. Average Cu and Mo contents are low, up to 0.2 and 0.01% respectively. The deposit is not explored at depth.