By Sergey M. Rodionov1, Alexander A. Obolenskiy2

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Durmin Metallogenic Belt of

Au-Ag Epithermal Vein Deposits

(Belt Dur) (Russia, Far East)

This Late Cretaceous metallogenic belt is related to veins related to East Sikhote-Alin volcanic-plutonic belt (too small to show at 10 M scale) that overlies and intrudes the Kiselyovka-Manoma Accretionary wedge terrane (too small to show at 5 M scale) along the southern side of the Amur River terrane, north of the Amur fault. The stratigraphy and structure are poorly known. The major deposit is at Durminskoye.

Durmin Au-Ag Epithermal Vein Deposit

This deposit (Moiseenko and Eirish, 1996) consists of five zones of hydrothermally altered, quartz-adularia-sericite, quartz-adularia, and quartz veins and breccia that range up to 220 m long and up to 7 m thick. The ore minerals are pyrite and pyrrhotite with rare arsenopyrite, galena, sphalerite, and chalcopyrite. Au/Ag ratio is 1: 20 to 30. The deposit is hosted in Late Cretaceous andesite, dacite, and rhyolite that overlie Early Cretaceous sandstone and siltstone sequence. Stocks and dikes of Late Cretaceous granite, granite porphyry, and granodiorite intrude the volcanic and sedimentary rock. The deposit is small.

Origin and Tectonic Controls for Durmin Metallogenic Belt

The belt is interpreted as forming during generation of granitoids along the East-Sikhote-Aline continental-margin arc that is tectonically related to oblique subduction of ancestral Pacific Ocean plate.

REFERENCES: Filippov, 1988; Natal'in, 1991; Moiseenko and Eirish, 1996.

Tumnin-Anyuy Metallogenic Belt of

Porphyry Sn, Cassiterite-Sulfide-Silicate

Vein and Stockwork, and Au-Ag Epithermal

Vein Deposits

(Belt TuA) (Russia, Far East)

This Late Cretaceous to Paleocene metallogenic belt is related to veins and granitoids in the perivolcanic zone of the East Sikhote-Alin volcanic-plutonic belt that overlies and intrudes the Kema, Luzhkinsky, and Samarka terranes. The major deposits are at Mopau and Tumninskoye.

Mopau Porphyry Sn Deposit

This deposit (Finashin, 1959; Usenko and Chebotarev, 1973) is the most important deposit of the belt and consists of lenticular zones in quartz-sericite rock. The zones contain abundant quartz-cassiterite, cassiterite-quartz-feldspar, quartz-cassiterite-chlorite, and quartz-cassiterite-arsenopyrite-chlorite veinlets. The veinlets range from paper-thin to 0.5 cm thick, and locally up to 10 cm thick. Where closely-spaced, the veinlets form an intricate stockwork up to 100 m across with high Sn content. The zones are over 400 m long and several tens of m thick. Some zones occur at contacts with diabase porphyry dikes. The deposit extends to depths of more than 200 m, is sulfide poor, and is easily concentrated. The deposit is hosted in a group of closely-spaced volcanic vents composed of rhyodacite breccia that is intruded by felsite porphyry intrusions and quartz porphyry dikes. The deposit is related to a major felsic pluton. The age of the deposit interpreted as Late Cretaceous to Paleogene. The deposit is small with an average grade of 0.3% Sn.

Tumninskoye Au-Ag Epithermal Vein Mine

This mine (Moiseenko and Eirish, 1996) occurs in the northern part of Samarka terrane. The deposit consists of low sulfide Au quartz veins that parallel, or rarely crossut strike in wall rocks. Isolated granite porphyry dikes also contain Au. The Au quartz veins range from about 200 to 500 m long and from 0.2 to 6.0 wide (locally up to 19) m. veins are predominantly (90 to 95%) composed by quartz. Ore are arsenopyrite, galena, sphalerite, chalcopyrite, pyrrhotite, gold, and wolframite Gangue minerals are presented, except quartz, by calcite, albite, adularia, sericite, and chlorite as well. Gangue quartz contains locally contains numerous host rock fragments. The deposit is hosted in Early Cretaceous sandstone and siltstone in the Oyemku anticline that trends north-northeast. The core of anticline consists of siltstone the flanks are composed by sandstone with interlayered siltstone. The main Au veins and rare dikes of granite porphyry, diorite porphyry, spessartite, and malchite occur along steeply-dipping (50 to 60^o) bedding faults. Bedding faults are widespread. The deposit is small with production of 576 kg of Au from 1962 to 1966.

Origin and Tectonic Controls for Tumnin-Anyuy Metallogenic Belt

The belt interpreted as forming during generation of granitoids along the East-Sikhote-Aline continental-margin arc related to subduction of ancestral Pacific Ocean plate.

REFERENCES: Moiseenko and Eirish, 1996; Nokleberg abd others, 1998, 2000, 2003; S.M. Rodionov, this study.

Luzhkinsky Metallogenic Belt of

Sn-W Greisen, Stockwork, and Quartz

Vein, Cassiterite-Sulfide-Silicate Vein and

Stockwork, W-Mo-Be Greisen, Stockwork,

and Quartz Vein, Porphyry Sn, Porphyry

Cu (±Au), Porphyry Cu-Mo (±Au, Ag),

and Polymetallic Pb-Zn ± Cu (±Ag, Au)

Vein and Stockwork Deposits

(Belt LZH) (Far East Rusia)

This mid-Cretaceous to early Tertiary metallogenic belt is related to veins, replacements, and granitoids in the East Sikhote-Alin volcanic-plutonic belt that overlies and intrudes Zhuravlevsk-Amur River terrane. The significant deposits in the belt are cassiterite-silicate-sulfide vein and porphyry Sn deposits (Yantarnoe), and Sn-W greisen, stockwork, and quartz vein deposits (Tigrinoe and Zabytoe). The Sn deposits are interpreted as forming in the mid-Cretaceous to early Tertiary between 100 and 50 Ma. Also in the same area are younger, generally uneconomic Sn-W greisen, stockwork, and quartz vein occurrences with K-Ar isotopic ages of 60 to 50 Ma age. In addition to Sn deposits, the northern Luzhkinsky metallogenic belt contains sparse small porphyry Cu (±Au) deposits (Verkhnezolotoe) that are hosted in Senomanian and Turonian monzodiorite in the northwestern part of the metallogenic belt near the Samarka accretionary-wedge terrane that contains abundant oceanic rocks. The porphyry Cu (±Au) deposits are coeval with the Sn deposits of the Luzhkinsky metallogenic belt, but presumably reflect the anomalous Cu-rich composition of the Samarka terrane.

Tigrinoe Sn-W Greisen, Stockwork, and Quartz Vein Deposit

This deposit (Korostelev and others, 1990; Gonevchuk and Gonevchuk, 1991) is complex and consists of: (1) a greisen along the contact of a Li-F granite pluton; (2) a linear stockwork consisting of a thick network (5 to 10 to 70 veinlets per meter) of parallel, north-south-trending quartz-topaz veins that range from 3 to 100 cm thick and are hosted in metasedimentary rock adjacent to the granite intrusion; and (3) a sulfide-cassiterite breccia pipe that contains rock fragments of the stockwork and greisen cemented by quartz and lesser carbonate, fluorite, and sulfides. Three stages occur: (1) early stage with quartz-molybdenite-bismuthinite; (2) middle stage of REE greisen with wolframite-cassiterite with high contents of Sc, Ni, and Ta; and (3) late stage with hydrothermal quartz-fluorite-carbonate-sulfide veins. In, Cd, Ag, and Se are enriched in sulfides in the two last stages. K-Ar isotopic age of the lithium-fluorine granite is 90 Ma ± 5%. A Rb-Sr isochron age for the Li-F granite is 86 ± 6 Ma with an initial Sr ratio of 0.7093. A Rb-Sr age for the greisen is 73 ± 18 Ma with an initial Sr ratio of 0.7105. The deposit is medium size with an average grade of 0.14% Sn and 0.045% WO₃.

Vysokogorskoe Cassiterite-Sulfide-Silicate Vein and Stockwork Deposit

This deposit (Litavrina and Kosenko, 1978; Ryabchenko, 1983) consists of quartz-chlorite-cassiterite, quartz-sulfide-cassiterite and sulfide-cassiterite veins and fracture zones in Early Cretaceous olistostrome partially overlain by Late Cretaceous felsic volcanic rock. Sn minerals are related to the areas of quartz-tourmaline alteration about 5-6 m thick. Average thickness of veins and zones is 1.2 to 1.4 m, with lengths of 400 to 500 m. Deposit extends to a depth of 700 m. In addition to cassiterite, deposit contains chalcopyrite, arsenopyrite, pyrrhotite; and rare galena and sphalerite. Sulfosalts of Bi and Ag are common. The deposit is medium size with a grade of 1.0% Sn. The deposit has been mined from 1960's to present, and is the largest mine in Kavalerova area.

Zimnee Sn-W Greisen, Stockwork, and Quartz Vein Deposit

This deposit (P.G. Korostelev and others, written commun., 1980; Nazarova, 1983) consists of breccia, breccia-and fracture-filling veins, zones of closely spaced veinlets, and pockets that occur in fracture zones. These structures range up to 1200 m long, are extensive down dip, and vary from several tenths of a meter to several tens of meters wide. The deposit occurs near a granodiorite body and consists mainly of pyrrhotite, pyrite, arsenopyrite, sphalerite, stannite, and cassiterite. Far from the granodiorite and in the upper part of veins, the deposit is mostly galena with finegrained cassiterite. Near the granodiorite, the deposit consists of breccia-bearing fragments of Sn-sulfide minerals that are cemented by a quartz-mica (greisen) aggregate with arsenopyrite and cassiterite. The K-Ar age of altered rocks related to the Sn-polymetallic deposits is 75 Ma. The K-Ar isotopic age of the greisen and granodiorite is approximately 50 Ma. The deposit is regionally metamorphosed and deformed. The deposit is small with an average grade of 0.1-3.0% Cu, 3.18% Pb, 0.59% Sn, and 4.09% Zn.

Arsenyevsky Sn-W Greisen, Stockwork, and Quartz Vein Mine

This mine (Rub and others, 1974; Radkevich and others, 1980) consists of a series of parallel, steeply-dipping quartz veins that extend up to 1000 m along strike and 600 to 700 m downdip. The deposit is closely controlled by moderate-to steeply-dipping rhyolite dikes with a K-Ar isotopic age of 60 Ma. The ore mineral assemblage is vertically zoned. From the top downwards, the assemblages are: quartz-cassiterite; quartz-arsenopyrite-pyrrhotite; polymetallic; and arsenopyrite-pyrrhotite. The rhyolite exhibits quartz-sericite alteration. Local miarolithic cavities are filled with cassiterite. The deposit is medium-size with an average grade of 2-3% Sn, and locally up to 20-25% Sn. The deposit also contains from 0.1-0.5% WO₃ , 1-2% Pb and Zn , and a few hundred ppm Ag. The deposit has been mined since 1970's.

Yantarnoe Porphyry Sn Deposit

This deposit (Rodionov, 1988) consists of veinlets and disseminations of cassiterite and sulfide minerals in a pipe-like body of volcanic breccia composed of trachyandesite and rhyolite. These units intrude Early Cretaceous clastic sedimentary rock. The older part of the deposit is in rhyolite in the pipe-like body that contains pyrite and chalcopyrite. The younger and major part of the deposit formed after intrusion of the explosive breccia and consists of metasomatic quartz-chlorite, quartz-sericite, and quartz-chlorite-sericite alterations that contain a sulfide-free cassiterite-chlorite-quartz assemblage, and a Sn-polymetallic assemblage rich in galena, sphalerite, and chalcopyrite. The host igneous rocks are spatially related to Paleocene volcanic vents with K-Ar isotopic ages of about 65 Ma. The deposit is small with an average grade of 0.1-2.17% Cu, 0.03-1.02% Pb, 7.3% Sn, and 0.7-2.22% Zn.

Origin and Tectonic Controls for Luzhkinsky Metallogenic Belt

The belt is interpreted as forming during generation of granitoids in back-arc part of the the East-Sikhote-Aline continental-margin arc that is tectonically linked to oblique subduction of ancestral Pacific Ocean Plate. Like the Sergeevka-Taukha and Kema metallogenic belts, the coeval Luzhkinsky metallogenic belt is hosted in East Sikhote-Alin volcanic-plutonic belt. The differences between the coeval metallogenic belts are interpreted as the result of the igneous rocks that host these metallogenic belts intruding different bedrock. The Sergeevka-Taukha metallogenic belt contains mainly B skarn, Zn-Pb (±Ag, Cu) skarn, and Pb-Zn polymetallic vein deposits, and is hosted in, or near igneous rocks that intrude the Taukha accretionary-wedge terrane that contains a complex assemblage of abundant Paleozoic and early Mesozoic oceanic rocks, and lesser Jurassic and Early Cretaceous turbidite deposits. In contrast, the Kema metallogenic belt contains mainly Ag-Au epithermal deposits, and is hosted in or near granitoids that intrude the Cretaceous island arc rocks of the Kema terrane. And in contrast, the Luzhkinsky belt is related to granitoid that intrudes the southern Zuravlevksk-Tumnin turbidite basin terrane. Additional controls for the Luzhkinsky metallogenic belt are: (1) the turbidite deposits in the Zuravlevksk-Tumnin terrane are enriched in Sn; and (2) the Luzhinsky belt occurs in the back-arc part of the East Sikhote-Alin igneous belt in which magnetite-series granitoids are predominate.

REFERENCES: Rub and others, 1974; Radkevich and others, 1980; Rodionov and Rodionova, 1980; Nazarova, 1983; Rodionov and others, 1984, 1987; Rodionov, 1988; Ruchkin and others, 1986; 1987; Gerasimov and others, 1990; Korostelev and others, 1990; Gonevchuk and Gonevchuk, 1991; Nokleberg and others, 1994, 1997, 2003; Gonevchuk and Korkorin, 1998; Gonevchuk and others, 1998.

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