Search

Results are presented which show that the major minerals in the Yantarnoye deposit, Primorye, are chalcopyrite (1.1 %) and sphalerite (0. 8 %), with nonmetallic minerals being represented by quartz, chlorite and sericite. A flow-sheet is presented for the processing of ore containing 0.40% Cu and 0.42% Zn by selective flotation to produce a Cu concentrate containing 18.6% Cu with a recovery of 85.7% and a Zn middling with a Zn content of 35% and recovery of 33.2%., Results are presented which show that the major minerals in the Yantarnoye deposit, Primorye, are chalcopyrite (1.1 %) and sphalerite (0. 8 %), with nonmetallic minerals being represented by quartz, chlorite and sericite. A flow-sheet is presented for the processing of ore containing 0.40% Cu and 0.42% Zn by selective flotation to produce a Cu concentrate containing 18.6% Cu with a recovery of 85.7% and a Zn middling with a Zn content of 35% and recovery of 33.2%.

The structure and petrology of concentric zoned intrusions in the Hasan-Grodekovo folded zone is described and a connection is suggested between some of these rocks and the platinum-group minerals and high-chromium spinel found in the Fadeevka and Zolotaya River placers. The characteristic features of the placer chromites correspond to those of chromite from ultrabasites in the complexes, while magnesian olivine in a placer PGM grain from the Zolotaya River placer is analogous to olivine in the dunites., The structure and petrology of concentric zoned intrusions in the Hasan-Grodekovo folded zone is described and a connection is suggested between some of these rocks and the platinum-group minerals and high-chromium spinel found in the Fadeevka and Zolotaya River placers. The characteristic features of the placer chromites correspond to those of chromite from ultrabasites in the complexes, while magnesian olivine in a placer PGM grain from the Zolotaya River placer is analogous to olivine in the dunites.

The deposits, which occur along a 12 000 km continental margin on the eastern Australian and Asian plates, were derived by diverse sampling of mantle-crust sources by Cainozoic basalts. Significant gemfields include New England, Anakie and Barrington in eastern Australia, those of Thailand, Vietnam, Cambodia and Laos in south-east Asia, Shandong, Hainan and Fujian in China and Primorye in the Russian Far East. They represent bimodal and, more rarely, polymodal suites of magmatic sapphire with rare ruby, metamorphic sapphire and ruby, and rare intermediate metasomatic suites., The deposits, which occur along a 12 000 km continental margin on the eastern Australian and Asian plates, were derived by diverse sampling of mantle-crust sources by Cainozoic basalts. Significant gemfields include New England, Anakie and Barrington in eastern Australia, those of Thailand, Vietnam, Cambodia and Laos in south-east Asia, Shandong, Hainan and Fujian in China and Primorye in the Russian Far East. They represent bimodal and, more rarely, polymodal suites of magmatic sapphire with rare ruby, metamorphic sapphire and ruby, and rare intermediate metasomatic suites.

The paper is based on the results of gravity modelling along three profiles and of mineralogical study related to the preparation of second-generation maps. The distribution of gold, mercury, tungsten and copper mineralisation in the Slavyanskii ore area was analysed in relation to a series of deep structures that have been distinguished. Also determined was the ore-controlling role of a basic complex, whose roots extend to the basalt zone, and its bounding tectonic zones on the distribution of gold ore, mercury and copper-nickel mineralisation in the Narvskii ore focus. The Gamovskii batholith controlled tungsten, the deep Zarubinskii fault copper and the Novgorodskii riftogenic structure the distribution of the Kraskinskii gold-ore focus; Upper Riphean blocks detected in this rift at depths of 1 km or more are potentially gold-bearing., The paper is based on the results of gravity modelling along three profiles and of mineralogical study related to the preparation of second-generation maps. The distribution of gold, mercury, tungsten and copper mineralisation in the Slavyanskii ore area was analysed in relation to a series of deep structures that have been distinguished. Also determined was the ore-controlling role of a basic complex, whose roots extend to the basalt zone, and its bounding tectonic zones on the distribution of gold ore, mercury and copper-nickel mineralisation in the Narvskii ore focus. The Gamovskii batholith controlled tungsten, the deep Zarubinskii fault copper and the Novgorodskii riftogenic structure the distribution of the Kraskinskii gold-ore focus; Upper Riphean blocks detected in this rift at depths of 1 km or more are potentially gold-bearing.

The structures of the ancient metamorphic assemblages and Cretaceous intrusions resulted from the NNW-directed compression typical of the Mesozoic to Cainozoic strike-slip margin of eastern Asia. Taxitic textures and layers formed in plutonic rocks and an ENE-trending linear system of syn- and antiforms developed. Gold was originally concentrated in hydrothermal quartz bodies accompanied by gneissification, and was confined to ENE-trending dynamoclastic and mylonitisation zones. This represents a 2-3 km wide, uninterrupted band marked by regional gold deposits and occurrences as well as geochemical aureoles. A repeated event of Au concentration within the band was closely related to Mesozoic activation of the NNE-trending sinistral strike-slip fault system under the NNW-oriented compression, when Au was also concentrated in NNW- trending echeloned extensional strike-slip faults., The structures of the ancient metamorphic assemblages and Cretaceous intrusions resulted from the NNW-directed compression typical of the Mesozoic to Cainozoic strike-slip margin of eastern Asia. Taxitic textures and layers formed in plutonic rocks and an ENE-trending linear system of syn- and antiforms developed. Gold was originally concentrated in hydrothermal quartz bodies accompanied by gneissification, and was confined to ENE-trending dynamoclastic and mylonitisation zones. This represents a 2-3 km wide, uninterrupted band marked by regional gold deposits and occurrences as well as geochemical aureoles. A repeated event of Au concentration within the band was closely related to Mesozoic activation of the NNE-trending sinistral strike-slip fault system under the NNW-oriented compression, when Au was also concentrated in NNW- trending echeloned extensional strike-slip faults.

The deposits and occurrences are controlled by NNE-trending sinistral deep fault zones, that concentrated diffuse gold-bearing fluids in the NW-trending tensional elements and transported them to the upper crust. Four such strike-slip fault zones are described: the Zapadno-Partizansky, Askold, Tigrovyi and Dunai zones. Gold mineralisation is uniform, of the plutonogenic-hydrothermal type, and is spatially and paragenetically related to small Late Cretaceous granitoid massifs. The Askold and Krinichnoe deposits are described and illustrated., The deposits and occurrences are controlled by NNE-trending sinistral deep fault zones, that concentrated diffuse gold-bearing fluids in the NW-trending tensional elements and transported them to the upper crust. Four such strike-slip fault zones are described: the Zapadno-Partizansky, Askold, Tigrovyi and Dunai zones. Gold mineralisation is uniform, of the plutonogenic-hydrothermal type, and is spatially and paragenetically related to small Late Cretaceous granitoid massifs. The Askold and Krinichnoe deposits are described and illustrated.

The greater part of the world's germanium reserves are concentrated in the Cainozoic lignite of Primorye, in the Russian Far East, along with rare earth elements, gold and platinum group metals. Ore mineralisation is concentrated in beds 0.5-13 m thick in the Lower Bikinsky, Pavlovsky and Shkotovsky coal basins, three of the eleven coal-bearing basins where former volcanism and related mineral spring activity have given rise to metalliferous coals. Data are presented on the orebodies' geological setting, shape and ore composition, and it is suggested that the mineralisation resulted from the discharge of ascending metalliferous solutions and gas jets from the basement into the sedimentary cover during various stages of basin evolution. Average Ge contents of coals in the various deposits range from 100 to about 1 000 ppm. Five basins have beds up to 3.5 m thick enriched in REE+Y to 0.1-0.2 wt%, or 0.2-1.2 wt% in ash. Anomalously high precious metal contents, from 10 to 1 000 ppb, are known in beds about 5 m thick in ten lignite deposits., The greater part of the world's germanium reserves are concentrated in the Cainozoic lignite of Primorye, in the Russian Far East, along with rare earth elements, gold and platinum group metals. Ore mineralisation is concentrated in beds 0.5-13 m thick in the Lower Bikinsky, Pavlovsky and Shkotovsky coal basins, three of the eleven coal-bearing basins where former volcanism and related mineral spring activity have given rise to metalliferous coals. Data are presented on the orebodies' geological setting, shape and ore composition, and it is suggested that the mineralisation resulted from the discharge of ascending metalliferous solutions and gas jets from the basement into the sedimentary cover during various stages of basin evolution. Average Ge contents of coals in the various deposits range from 100 to about 1 000 ppm. Five basins have beds up to 3.5 m thick enriched in REE+Y to 0.1-0.2 wt%, or 0.2-1.2 wt% in ash. Anomalously high precious metal contents, from 10 to 1 000 ppb, are known in beds about 5 m thick in ten lignite deposits.

As well as 4 papers on the Permian and Triassic terranes, magmatism, tectonic processes and palaeogeography of the area and 13 papers on its conodont, ostracod, radiolarian, plant, ammonoid, sphinctozoan and coral biostratigraphy, 4 papers are presented on mineral deposits and their setting: Epithermal gold-silver mineralisation of late Palaeozoic volcanic-plutonic complexes of south-west Primorye, by Khomich V.G., Ivanov V.V., Zinkov A.V. and Zenin A.L., p.175-181, 8 refs., on vein-metasomatic bodies and epigenetically transformed volcanites on the margin of the Khanka massif; Tectono-sedimentary complexes of the Dalnegorsk ore region, by Parnjakov Y.P., p.183-189, 19 refs., on its Triassic to Lower Cretaceous nappes, thrusts and olistostromes; Late Mesozoic ore-bearing olistostromes of Sikhote-Alin and its formation equivalents in Japan Sea region, by Izosov L.A. and Levashov G.B., p.191-196, 13 refs., on the tungsten, skarn polymetallic, boro-silicate, pyrite and iron-manganese province; and Phosphate grains (pellets) of phosphorites from the Phosphoria Formation, USA, by Shkolnik E.L., Zhegallo H.A. and Eganov E.A., p.197-202, 6 refs., As well as 4 papers on the Permian and Triassic terranes, magmatism, tectonic processes and palaeogeography of the area and 13 papers on its conodont, ostracod, radiolarian, plant, ammonoid, sphinctozoan and coral biostratigraphy, 4 papers are presented on mineral deposits and their setting: Epithermal gold-silver mineralisation of late Palaeozoic volcanic-plutonic complexes of south-west Primorye, by Khomich V.G., Ivanov V.V., Zinkov A.V. and Zenin A.L., p.175-181, 8 refs., on vein-metasomatic bodies and epigenetically transformed volcanites on the margin of the Khanka massif; Tectono-sedimentary complexes of the Dalnegorsk ore region, by Parnjakov Y.P., p.183-189, 19 refs., on its Triassic to Lower Cretaceous nappes, thrusts and olistostromes; Late Mesozoic ore-bearing olistostromes of Sikhote-Alin and its formation equivalents in Japan Sea region, by Izosov L.A. and Levashov G.B., p.191-196, 13 refs., on the tungsten, skarn polymetallic, boro-silicate, pyrite and iron-manganese province; and Phosphate grains (pellets) of phosphorites from the Phosphoria Formation, USA, by Shkolnik E.L., Zhegallo H.A. and Eganov E.A., p.197-202, 6 refs.

The main geochemical problems are connected with the transformation of natural water chemistry by mining wastes. An investigation of many mines in Primorye, including cassiterite-sulphide, Zn-Pb, skarn-polymetallic and skarn-scheelite-sulphide deposits, in the southern part of the Russian Far East, showed that their mining waters have high concentrations of heavy metals and aluminium. Water acidity is primarily connected to the amount of acid-forming sulphide minerals in ores and also depends on the neutralising capacity of surrounding rocks. A considerable quantity of metals occur in the waters in dissolved form, exceeding natural levels by 2-5 orders of magnitude; this cannot be reduced to background levels even after multiple dilution. Results of analyses of background waters, mining waters, tailings drainage and sediments are presented and proposals to ameliorate pollution are discussed., The main geochemical problems are connected with the transformation of natural water chemistry by mining wastes. An investigation of many mines in Primorye, including cassiterite-sulphide, Zn-Pb, skarn-polymetallic and skarn-scheelite-sulphide deposits, in the southern part of the Russian Far East, showed that their mining waters have high concentrations of heavy metals and aluminium. Water acidity is primarily connected to the amount of acid-forming sulphide minerals in ores and also depends on the neutralising capacity of surrounding rocks. A considerable quantity of metals occur in the waters in dissolved form, exceeding natural levels by 2-5 orders of magnitude; this cannot be reduced to background levels even after multiple dilution. Results of analyses of background waters, mining waters, tailings drainage and sediments are presented and proposals to ameliorate pollution are discussed.

The use is discussed of fine screening instead of hydraulic classification at the Primorskaya plant. Fine screening allowed a final product to be obtained which was suitable for flotation immediately after grinding, and is recommended for ores with large differences in the density of valuable minerals and barren rock. The results of full-scale tests using a Derrick screen and polyurethane screening media with 0.23 mm aperture size showed that scheelite recovery from difficult to treat -0.25+0.08 mm size fractions could be increased by 25%-35 %, with 10%-12% of valuable minerals from the mill feed being suitable for flotation., The use is discussed of fine screening instead of hydraulic classification at the Primorskaya plant. Fine screening allowed a final product to be obtained which was suitable for flotation immediately after grinding, and is recommended for ores with large differences in the density of valuable minerals and barren rock. The results of full-scale tests using a Derrick screen and polyurethane screening media with 0.23 mm aperture size showed that scheelite recovery from difficult to treat -0.25+0.08 mm size fractions could be increased by 25%-35 %, with 10%-12% of valuable minerals from the mill feed being suitable for flotation.

The session included papers on the genesis of mineral deposits in the continental-margin tectonic settings of the Russian Far East and the north Japanese and Kuril island arcs. Among the topics covered were the geochemistry and geodynamic regimes that formed zeolites in volcanogenic complexes of Primorye, the geochemistry of basalts from Paramushir Island, the development of a database on the geology and geochemistry of igneous rocks in Central Asia, silicic volcanic glasses of Primorye, the evolution of magmatism in SW Primorye from crust-mantle pulsees to subduction-dominated processes, and the composition of magmatic rocks in the Indigirka extension belt of East Yakutia., The session included papers on the genesis of mineral deposits in the continental-margin tectonic settings of the Russian Far East and the north Japanese and Kuril island arcs. Among the topics covered were the geochemistry and geodynamic regimes that formed zeolites in volcanogenic complexes of Primorye, the geochemistry of basalts from Paramushir Island, the development of a database on the geology and geochemistry of igneous rocks in Central Asia, silicic volcanic glasses of Primorye, the evolution of magmatism in SW Primorye from crust-mantle pulsees to subduction-dominated processes, and the composition of magmatic rocks in the Indigirka extension belt of East Yakutia.

Extended abstracts are presented on metalliferous and gemstone deposits associated with alkali basalts, high-alumina schists and quartzites, ophiolites, serpentinites, mantle plumes and hot spots, and mafic-ultramafic complexes in the Russian Far East and other parts of the world. Locations or regions discussed include Podgelbanochny in Primorye, western Transbaikal, Izu-Ogasawara-Mariana and Tong trench, Sredinny Ridge in Kamchatka, central and south Urals, the Guarani aquifer in Brazil, Serra Geral/Arapey in Brazil and Uruguay, Ouro Preto, Ghundao Hill, Sanarka River, Upper Priamuriye and Alaska. Mineralisation considered includes phosphate minerals, platinum group metals, cobalt, nickel, amethyst, topaz and corundum., Extended abstracts are presented on metalliferous and gemstone deposits associated with alkali basalts, high-alumina schists and quartzites, ophiolites, serpentinites, mantle plumes and hot spots, and mafic-ultramafic complexes in the Russian Far East and other parts of the world. Locations or regions discussed include Podgelbanochny in Primorye, western Transbaikal, Izu-Ogasawara-Mariana and Tong trench, Sredinny Ridge in Kamchatka, central and south Urals, the Guarani aquifer in Brazil, Serra Geral/Arapey in Brazil and Uruguay, Ouro Preto, Ghundao Hill, Sanarka River, Upper Priamuriye and Alaska. Mineralisation considered includes phosphate minerals, platinum group metals, cobalt, nickel, amethyst, topaz and corundum.

The two gold mining areas considered are Severovostok and Primorye. The history of mining in these areas is summarised together with notes on the mining methods used at present. The climate causes special problems for miners in these areas - the most productive periods being between June and August when the ground is thoroughly thawed., The two gold mining areas considered are Severovostok and Primorye. The history of mining in these areas is summarised together with notes on the mining methods used at present. The climate causes special problems for miners in these areas - the most productive periods being between June and August when the ground is thoroughly thawed.

Primorye consists of a series of accreted terranes. The Proterozoic-Lower Palaeozoic Khanka terrane contains pre-amalgamation stratiform base metal deposits such as the Voznesenka zinc deposit in Cambrian limestones. Later skarns and greisen overprinted the stratiform mineralisation during intrusion of Silurian-Early Devonian Li- and F-rich granites, to give economic tin and fluorite in the Voznesenka district. The complex, post-accretionary event along the Palaeozoic active margin also resulted in rare earth element and gold telluride mineralisation and high-temperature topaz-mica alteration of the Cambrian limestones. Mesozoic units of the Sikhote-Alin terrane have no pre-amalgamation deposits except pyrite related to oceanic basalt; most deposits are syn-accretionary and associated with volcano-plutonic complexes: tungsten in Jurassic rocks is associated with Early Cretaceous granodiorites/diorites and skarns, tin with Middle-Late Cretaceous volcanic belts and flysch. In the Coastal Disrupted terrane, early felsic volcanics erupted in an aqueous environment gave rise to intense tourmalinisation and the giant boro-silicate skarn deposits of the Dalnegorsk mining district. Many tin and base metal deposits formed during Late Cretaceous-Early Tertiary volcanism and the youngest deposits are Early Tertiary sulphosalt silver lodes., Primorye consists of a series of accreted terranes. The Proterozoic-Lower Palaeozoic Khanka terrane contains pre-amalgamation stratiform base metal deposits such as the Voznesenka zinc deposit in Cambrian limestones. Later skarns and greisen overprinted the stratiform mineralisation during intrusion of Silurian-Early Devonian Li- and F-rich granites, to give economic tin and fluorite in the Voznesenka district. The complex, post-accretionary event along the Palaeozoic active margin also resulted in rare earth element and gold telluride mineralisation and high-temperature topaz-mica alteration of the Cambrian limestones. Mesozoic units of the Sikhote-Alin terrane have no pre-amalgamation deposits except pyrite related to oceanic basalt; most deposits are syn-accretionary and associated with volcano-plutonic complexes: tungsten in Jurassic rocks is associated with Early Cretaceous granodiorites/diorites and skarns, tin with Middle-Late Cretaceous volcanic belts and flysch. In the Coastal Disrupted terrane, early felsic volcanics erupted in an aqueous environment gave rise to intense tourmalinisation and the giant boro-silicate skarn deposits of the Dalnegorsk mining district. Many tin and base metal deposits formed during Late Cretaceous-Early Tertiary volcanism and the youngest deposits are Early Tertiary sulphosalt silver lodes.

This century (up to 1992 or 1993) the area has produced a recorded 4 683.7 tonnes of gold, 17 t of platinum, 199 400 t of tin, over 22 000 000 t of borate products, 30 442 t of mercury and 59 000 t of tungsten, as well as large quantities of silver, fluorite, lead, zinc and industrial minerals and minor amounts of beryllium, bismuth, uranium and antimony. The enormous role of government in the industry's evolution contrasts with developments in North America. The review focuses mainly on the maritime regions: Chukotka includes Au and Sn placers and the Iultin, Svetloe and Valkumei hard-rock Sn(-W-Be) mines; Magadan includes parts of the Central Kolyma-Indigirka River Au, Ag and Sn districts and Kubaka, Dukat, Karemkan and Ust Omchug Au-Ag mines; Khabarovsk shares the Amur placer districts and has Agnie-Afanasevskoe Au and Konduer Pt mines; Kamchatka has Aginskaya and Zolotoi Au-Ag mines; Sakhalin has coal; and Primorye has Askold Au, Yaroslavka F and Kavalerevo and Dalnegorsk Sn-Pb-Zn-B mines. There is some mention of other areas such as the eastern Sakha Republic (Yakutia), Amur and Chita., This century (up to 1992 or 1993) the area has produced a recorded 4 683.7 tonnes of gold, 17 t of platinum, 199 400 t of tin, over 22 000 000 t of borate products, 30 442 t of mercury and 59 000 t of tungsten, as well as large quantities of silver, fluorite, lead, zinc and industrial minerals and minor amounts of beryllium, bismuth, uranium and antimony. The enormous role of government in the industry's evolution contrasts with developments in North America. The review focuses mainly on the maritime regions: Chukotka includes Au and Sn placers and the Iultin, Svetloe and Valkumei hard-rock Sn(-W-Be) mines; Magadan includes parts of the Central Kolyma-Indigirka River Au, Ag and Sn districts and Kubaka, Dukat, Karemkan and Ust Omchug Au-Ag mines; Khabarovsk shares the Amur placer districts and has Agnie-Afanasevskoe Au and Konduer Pt mines; Kamchatka has Aginskaya and Zolotoi Au-Ag mines; Sakhalin has coal; and Primorye has Askold Au, Yaroslavka F and Kavalerevo and Dalnegorsk Sn-Pb-Zn-B mines. There is some mention of other areas such as the eastern Sakha Republic (Yakutia), Amur and Chita.

A field conference within the framework of IGCP project 373, on Correlation, anatomy and magmatic-hydrothermal evolution of ore-bearing felsic igneous systems in Eurasia, held 1-12 September 1998, provided the opportunity to study and discuss some of the major deposits of the Primorye region. It lies at the conjunction of Palaeozoic units of the Central Asian fold belts with the young circum-Pacific subduction-accretion belt. The Voznesenka fluorite and rare metal district includes Russia's largest fluorite deposit, with concentrate production to date of 6 500 000 t grading 92% CaF2. The Dalnegorsk borosilicate and polymetallic ore district includes a skarn deposit with 3% of world boron reserves and 13 000 000 t ore produced since 1946, while polymetallic skarn and vein deposits host 10% of Russian Pb and 7% of Zn reserves. The Kavalerovo tin ore district produced about 30% of the tin mined in the former USSR and is the second largest tin-producing region in Russia., A field conference within the framework of IGCP project 373, on Correlation, anatomy and magmatic-hydrothermal evolution of ore-bearing felsic igneous systems in Eurasia, held 1-12 September 1998, provided the opportunity to study and discuss some of the major deposits of the Primorye region. It lies at the conjunction of Palaeozoic units of the Central Asian fold belts with the young circum-Pacific subduction-accretion belt. The Voznesenka fluorite and rare metal district includes Russia's largest fluorite deposit, with concentrate production to date of 6 500 000 t grading 92% CaF2. The Dalnegorsk borosilicate and polymetallic ore district includes a skarn deposit with 3% of world boron reserves and 13 000 000 t ore produced since 1946, while polymetallic skarn and vein deposits host 10% of Russian Pb and 7% of Zn reserves. The Kavalerovo tin ore district produced about 30% of the tin mined in the former USSR and is the second largest tin-producing region in Russia.

The Pb-Zn deposits of the Dalnegorsk ore district may be grouped into skarn (about 80%) and vein types. The location of the skarn deposits, which are of major commercial value, is controlled by carbonate units within the Early Cretaceous accretionary-wedge Taukha terrane. The orebodies are pipe/lens-shaped with vertical zoning and have been traced to depths of 1 000-1 500 m. Major ore minerals are galena, sphalerite, pyrrhotite, chalcopyrite, hedenbergite, quartz and calcite, with Cd, Ag, Bi and Cu present as minor elements. The ore metallurgy allows high recoveries of the major components: 93.9% of lead and 91.4% of zinc. Tailings components of possible interest are Au, In, Se, Te, Th, Ga, Ge, Ni, Va, Zr, Sc and Cu. The principal deposits include Nikolayevskoye, which produces 400-500 tons/a of ore containing 2.5-5.0% Pb, 2.0-5.0% Zn and 20-100 g/t Ag, Verkhnee skarn deposit, which also includes Cu-rich sulphide veins, and Yuzhnoye, with relatively high silver grades., The Pb-Zn deposits of the Dalnegorsk ore district may be grouped into skarn (about 80%) and vein types. The location of the skarn deposits, which are of major commercial value, is controlled by carbonate units within the Early Cretaceous accretionary-wedge Taukha terrane. The orebodies are pipe/lens-shaped with vertical zoning and have been traced to depths of 1 000-1 500 m. Major ore minerals are galena, sphalerite, pyrrhotite, chalcopyrite, hedenbergite, quartz and calcite, with Cd, Ag, Bi and Cu present as minor elements. The ore metallurgy allows high recoveries of the major components: 93.9% of lead and 91.4% of zinc. Tailings components of possible interest are Au, In, Se, Te, Th, Ga, Ge, Ni, Va, Zr, Sc and Cu. The principal deposits include Nikolayevskoye, which produces 400-500 tons/a of ore containing 2.5-5.0% Pb, 2.0-5.0% Zn and 20-100 g/t Ag, Verkhnee skarn deposit, which also includes Cu-rich sulphide veins, and Yuzhnoye, with relatively high silver grades.

The geology, mineralogy and geochemistry of the Terinstoye and Iskra deposits are presented and the crystallisation discussed of (Bi,Pb)4(Se,S, Te)3 at both deposits, as well as (Bi,Pb)6(Se,S,Te)5, Cu3(Bi,Pb,Ag)(S, Se)3 and (Bi,Pb,Ag)5Se4 + Cu2(S,Se) at Iskra. The two deposits are located about 300 km apart in the Zhuravlevskiy granite terrain. The Terinstoye veins are related to a monzodiorite stock and associated diorite-porphyry and rhyolite dykes. Laytakarite and other Se-Te-Bi mineral associations are accompanied by hessite, stannite, bismuthite, lillianite, cosaltite, icunolite, galena and galenobismuthite. At Iskra, the ore zones are hosted by siltstones and associated with rhyolite, rhyodacite and andesite dykes; they are terminaed by the tectonic zone bounding igneous suites of andesites, tuffs and rhyolites. As well as the various Se-bearing laytakarite phases, minerals include chalcopyrite, sphalerite and pyrite., The geology, mineralogy and geochemistry of the Terinstoye and Iskra deposits are presented and the crystallisation discussed of (Bi,Pb)4(Se,S, Te)3 at both deposits, as well as (Bi,Pb)6(Se,S,Te)5, Cu3(Bi,Pb,Ag)(S, Se)3 and (Bi,Pb,Ag)5Se4 + Cu2(S,Se) at Iskra. The two deposits are located about 300 km apart in the Zhuravlevskiy granite terrain. The Terinstoye veins are related to a monzodiorite stock and associated diorite-porphyry and rhyolite dykes. Laytakarite and other Se-Te-Bi mineral associations are accompanied by hessite, stannite, bismuthite, lillianite, cosaltite, icunolite, galena and galenobismuthite. At Iskra, the ore zones are hosted by siltstones and associated with rhyolite, rhyodacite and andesite dykes; they are terminaed by the tectonic zone bounding igneous suites of andesites, tuffs and rhyolites. As well as the various Se-bearing laytakarite phases, minerals include chalcopyrite, sphalerite and pyrite.

Four deposits and numerous occurrences have been found in the 1 000 km Kema metallogenic belt. The epithermal-type mineralisation is controlled by faults and concentrated in quartz, quartz-fluorite-adularia and sulphide-quartz veins hosted by Upper Cretaceous to Lower Tertiary volcanic rocks. The vein systems extend for hundreds of metres along strike and vary in width from tens of centimetres to 50-60 m. They contain from 1 to 50-80 ppm Au as native metal and from 1 to 1 000 ppm Ag in argentite, pyrargyrite, stephanite and other sulphosalts. Early testwork on ores from the most studied deposits, Primorskoye and Salut, indicated that gold could be extracted from both by simple cyanidation without gravity or flotation preparation, with more than 90% of Au and 70% of Ag recoverable by heap leaching. Other sites of interest are Bystroye, Stockwork (Shtokverkovoye) and Paveletskoye., Four deposits and numerous occurrences have been found in the 1 000 km Kema metallogenic belt. The epithermal-type mineralisation is controlled by faults and concentrated in quartz, quartz-fluorite-adularia and sulphide-quartz veins hosted by Upper Cretaceous to Lower Tertiary volcanic rocks. The vein systems extend for hundreds of metres along strike and vary in width from tens of centimetres to 50-60 m. They contain from 1 to 50-80 ppm Au as native metal and from 1 to 1 000 ppm Ag in argentite, pyrargyrite, stephanite and other sulphosalts. Early testwork on ores from the most studied deposits, Primorskoye and Salut, indicated that gold could be extracted from both by simple cyanidation without gravity or flotation preparation, with more than 90% of Au and 70% of Ag recoverable by heap leaching. Other sites of interest are Bystroye, Stockwork (Shtokverkovoye) and Paveletskoye.

An EIA has been carried out for an integrated mining and milling project in Prymorsky Territory, Russia. The major target ore consists of a stockwork deposit containing commercial amounts of Sn, W and associated Pb, Zn and Cu. The current state of the soil, vegetation, wildlife, surface water and air circulation and related meteorology are discussed along with the potential effects of the project. It is concluded that serious environmental damage would be caused, both within the building area and the surrounding region. The pollution of surface waters would cause the most significant damage along with deterioration in the habitats of wildlife. This could be overcome by preventing high concentrations of metals in the mine water, changing the route of the drain tunnel, providing drainage under one of the dumps and undertaking recultivation works., An EIA has been carried out for an integrated mining and milling project in Prymorsky Territory, Russia. The major target ore consists of a stockwork deposit containing commercial amounts of Sn, W and associated Pb, Zn and Cu. The current state of the soil, vegetation, wildlife, surface water and air circulation and related meteorology are discussed along with the potential effects of the project. It is concluded that serious environmental damage would be caused, both within the building area and the surrounding region. The pollution of surface waters would cause the most significant damage along with deterioration in the habitats of wildlife. This could be overcome by preventing high concentrations of metals in the mine water, changing the route of the drain tunnel, providing drainage under one of the dumps and undertaking recultivation works.

An electron-microscopic study is reported of monocrystalline diamonds, heavy minerals and carbonado (polycrystalline diamond) grains from the Au-bearing placers of the Primorye region of Russia. Morphology, crystal structure and temperatures of formation of different phases were investigated. Apart from diamond, the minerals included native Al, rutile, anatase, zircon, xenotime, monazite, gorceixite (Ba hydroxyl alumophosphate), florencite, muassanite (alpha-SiC), native Ta, corundum, amorphous Fe, magnesite and perovskite., An electron-microscopic study is reported of monocrystalline diamonds, heavy minerals and carbonado (polycrystalline diamond) grains from the Au-bearing placers of the Primorye region of Russia. Morphology, crystal structure and temperatures of formation of different phases were investigated. Apart from diamond, the minerals included native Al, rutile, anatase, zircon, xenotime, monazite, gorceixite (Ba hydroxyl alumophosphate), florencite, muassanite (alpha-SiC), native Ta, corundum, amorphous Fe, magnesite and perovskite.

Rare metal granites and basic dykes of two ore fields of the Primorye territory which differ in age and geological environment are described. Basic dykes intersect greisens and quartz veins with cassiterite and are replaced by mica-fluorite mineralisation. It is supposed that contrast magmatic associations and related tantalum, tin and fluorite mineralisation have a heterogenic magmatic source - crustal and mantle., Rare metal granites and basic dykes of two ore fields of the Primorye territory which differ in age and geological environment are described. Basic dykes intersect greisens and quartz veins with cassiterite and are replaced by mica-fluorite mineralisation. It is supposed that contrast magmatic associations and related tantalum, tin and fluorite mineralisation have a heterogenic magmatic source - crustal and mantle.

The occurrence of the native metals, their association with a carbonaceous material and other criteria indicate a highly reducing environment and they are interpreted as having originated from dry mantle gases., The occurrence of the native metals, their association with a carbonaceous material and other criteria indicate a highly reducing environment and they are interpreted as having originated from dry mantle gases.