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

Tayozhnoe Ag Epithermal Vein Deposit
The Tayozhnoe Ag epilhcrmal vein dcpasit (A.N. Rodjonov and others, written commun., 1976; Pakhomova and others,
1997) consists of steeply-dipplng quartz veins which occur along northwest to north-south fractures whicb cut coarse-$rained,
Early Cretaceous sandstone. The veins are 100 to 500 m long and O f to 2 rn thick, and also occur laterally under the contact
between sandstone and overlying 50-m-thick section of Late Cretaceous felsic volcanic rocks. The ore minerals occur withln the
veins, and in metasomatic zones along the sub-horizontal contact behnreen veins and overlying volcanic rocks. The major Agbearing
minerals are Ag sulfosalts md sulfides. Pyrltc and menopyrite are rare and formed before Ag-b&g mumah. In the
upper part of veins, Ag occurs in tebrahedrite, fieibergite, stephaaite, pyrargyribe, and polybasite. At middle depths, Ag occurs in
acanthite and stephanite dominate, dong with menopyrite and allargenturn also occur, whereas acanthite dominates at depth. The
deposit is medium size with an average grade of 50-2000 g/t Ag and 1 g/t Au. The deposit has been mined since the 1980's, and is
assumed to be related to a Paleocene rhyolite volcan~plutonic assemblage.
Verkhnezolotoe Porphyry Cu Deposit
The Verkhnezolotoe porphyry Cu dcpxit (Orlovsky and others, 1988) occurs at the northwest margin of a caldera whicb
contains dike-like bodies of calc-akabe andesite porphyry which is interpreted as tongues of a dome-like subvolcanic intrusion.
A stockwork occurs in a circular auraole of hydrothermally altered rocks, witb dimensionsof 200 m2, occurs over the inhusive
dome. Successive alterations consist of: (1) q~-biotite-actinolite with pyroxene and epidote; (2) quartz-biotite-actinolite; (3)
quartz-biotite-sericite and local cbtoritc; d (4) qlwtz-hydromica with carbonate. The stockwork indudes the first three
alterations and consists of a thick network of quark-epidote-actinolite veinlets and lenses up to 2 to 3 cm thick with chalcopyrite,
bornite, and pyrite. The stockwork is related fa a diwitc stock. Tke stockwork boundary coincidts with the aureole of the biotite
alteration. An intensely-fractured breccia of mineralized siliceous silktone was encountered by drill holes which extend to 100 m
depth. The ore minerals in breccia zones arc chalcopyrite, bornite, molybdenite, pyrite, rarely pyrrhotite, ci~banite, arsenopyrite,
galena, and sphalerite. Carbonatc.chalcopyrite veiaIcto also occur. A m e of oxidized ore up to 20 to 30 in deep caps the deposit.
The deposit is small with average grades of 3 g/t Au, 86 g/t Ag, 0.35-2.27% Cu, 0.6% Pb, and 0.26% Sn.
Origin of and Tectonic Controls for
Kema Metallogenic Belt
The Cretaceous grauitoid rocks hosting the Kema metallogenic belt are part of the East Sikhote-Alin volcaaic-plutonic
belt of Late Cretaceous and early Tertiary age (fig. 79) which is described in the above section the origin of the Taulrba
metallogenic belt. Other related, coeval mecaHogenic belts hosted in the East-Sikhote-Alina volcanic belt are the Lrzhkinsky,
Lower Amur, Sergeevka (SG), and Taukha (TK)belts (fig. 79; Ublm 3,4). In the Kema metallogenic bit, the Cretaceous
granitoid rocks of the East SikboteAlin belt intrude the Kana island-arc terrane which consists chiefly of distal turbidite deposits,
andesite and basalt flows, breccia, tuft, and interbeddtd shallow-marine volcaniclastic rocks which contain Aptian to Albian
pelecypods (Nokleberg and others, 1994~). The volcanic rocks range mainly born tholeiitic and calc-alkah. In the Kern
metallogenic belt, the volcanic rocks an mostly intermediate and moderately felsic, rhyolite and lesser basalt with K-Ar
ages of about 55 to 60 Ma. la contrast to the nearby Taukiba metallogenic belt, the Kema metallogenic belt contains mainly Ag-
Au epithermal deposits and is hosted in or near granitoid rocks of the East Sikhote-Ah belt where it intrudes the Cretaceous
island-arc rocks of the Kema krrane.
Luzhkinsky Metallogenic Belt of Sn Oreken,
Sn Polymetallic Vein, Sn silica+ulfkle win,
and Porphyry Sn Deposits (BeR LZ)
Southern Part of Russian Southeast
The Luzhkinsky metallogenic belt of Sn greisun and So polymetallic vein, and porphyry Sn deposits (fig. 79; tabh 3,4)
occurs in the southern part of the Russian Southeast (Gonevchuyk and Kokorin, 1998). The belt is hosted in the Late Cretaceous
and early Tertiary granitoid rocks of the East Sikhote-ALin volcanic-plutonic belt which intrude the southern part of the
Zhuravlesk-Tumnm turb~dite basin teme (Nokleberg and others, 1994c, 1997~). The Luzhlunsky metallogenic belt contains one
of the major group of Sn mlnes in the Russian Southeast (Vwilenko and others, 1986; Radkevich, 1991; Gonevchuk and others,
1998). The significant deposlts in the belt are Sn silicatesulfide vein deposits at Arsenyevsoe, Khntstalnoe, and Vysokogorskoe
(fig. 89), Sn polymetallic vein deposits at Dalnetayozhnoe, Iskra (fig. 90), Nizhnee, and Zimnee, a polymetall~c vein deposit at
Yuzhnoe, porphyry Cu and porphyry Cu-Mo deposits al Lazurnoe, Malinovskoe, Verkhnezolotoe, and Zarechnae, porphyry Sn
deposits at Yantarnoe and Zvezdnoe, and Sn-W greisen deposits at Tigrinoe and Zabytoe (table 4) (Nddeberg and ottwFs 19978,
b, 1998; Gonevchuk and others, 1998).
Sn greisen and Sn polymetallic Vein DeposB
The Sn greisen and Sn polymetallic vein deposits of the Luzhkinsky belt formed in the mid-l=retacews andearly Tertiary
between about 90 to 100 and 60 Ma (Gonevchuk and Korkorin, 1998). The older deposits formed in the early Late Cretwxm (90