An Erratum to this paper has been published: https://doi.org/10.1134/S1028334X22330017

In the Sn–W greisen deposits of the Karadub ore field, rare arsenates of REEs chernovite-(Y) and gasparite-(Ce), associated with topaz, fluorite, fluocerite, and bastnaesite, have been identified. They replace early xenotime-(Y) and monazite-(Ce). Chernovite-(Y) and gasparite-(Ce) from Sn–W greisens differ in their chemical composition from the same minerals previously described elsewhere. Chernovite-(Y) differs in the minimum content of Y with only 0.47 to 0.26 atoms in the formula (a.p.f.) and a relatively high content of light REEs of 0.111–0.254 (a.p.f.). Gasparite-(Ce) has a high Nd content of 0.28 (a.p.f.). REE arsenates were formed by substituting xenotime (Y), monazite (Ce), and REE-bearing fluorite under strongly oxidizing conditions.

Abstract—The paper presents the results of mineralogical studies of tin–silver–polymetallic ores localized at the deep level (500–700 m below the surface) of the Yuzhnoe Cenomanian deposit. On the deep southwestern flank of vein no. 4, indications of ore recrystallization have been revealed. Mineral segregations (inclusions) with sharp boundaries and myrmekite texture as fine intergrowths of pyrrhotite with nisbite (NiSb2) or breithauptite (NiSb) are found in recrystallized ores at the grain boundaries of nickel-bearing pyrrhotite and galena with abundantly disseminated Ag–Sb minerals. Less frequently, myrmekite-like segregations are pyrrhotite graphically intergrown with gudmundite or nonstoichiometric chemically variable Ag sulfoantimonide (phase X). Tiny grains of Ag-bearing chalcopyrite and stannite are frequently observed in pyrrhotite–sulfoantimonide intergrowths. The formation of myrmekite-like segregations is presumably associated with ore transformation in the fluid-thermal field of a Maastrichtian postore leucogranite intrusion. Local segregations of the mobilizate (mobile phase) formed as a metal-bearing sulfoantimonide melt during ore recrystallization at a temperature of ~600°C as a result of the redistribution and migration of trace elements to the contacts of mineral grains. Heterogenous distribution and variable chemical composition of micrographic segregations reflect immiscibility and differentiation of the formed metal-bearing sulfoantimonide melt during its liquidus evolution. The final avalanche-like quenching crystallization of melt inclusions was implemented below 300°C.

Geochemical, isotope-geochemical, geochronolochical and thermobarometric study showed that the Badzhal, Mayo-Chan and Kavalerovo zones from Sikhote-Alin-Northern Sakhalin orogenic belt comprise: (1) oldest and geochemically and isotopically distinctive alkali mafic rocks, whose formation was related to mantle (asthenospheric) diapir. The possible regional distribution of the diapir is likely marked by subalkaline rocks (monzonites) having mantle Sr (0,7050) and Nd (0,5125) isotopic compositions at the Central (Tigrinoe deposit) and Southern (Kavalerovo district) Sikhote-Alin; (2) Tin-bearing ore-magmatic systems of the studied zones at the “ore region” level have similar intricate multi-root structure of generation area. 3) Magmatic evolution accompanying by increasing ore-bearing potential results in the final appearance of Li-F granites in the Badzhal Complex, and tourmaline granites in the Silinka Complex of the Myao-chan zone (Gonevchuk, 2002). The elevated F and Cl contents and high water content as parameters responsible for ore potential of melt were confirmed by thermobarometric data (Bortnikov et al, 2019). Some associations of fluid and melt inclusions indicate that magma crystallization was accompanied by degassing with exsolution of water-rich fluids, which is required to form ore bodies in OMS. These data confirm significant role of mantle in the formation of the Myao-Chan and Badzhal zones, as well as early cassiterite—stannite—sulfide stage of the Arsen’evskoe deposit of the Kavalerovo district. Numerical simulation of granitoids of the studied zones performed using logical-information method by I.A. Chizhova (2010) confirms crustal-mantle nature of magmatic complexes formed under transform continental margin and subduction settings. These systems are characterized by different geochemical features, in particular, different proportions of high-field strength (Sc, Y, Zr, Hf, Pb, U, Th, Nb), REE, and siderophile (Co, Ni, Cr, V, Cu) elements. Obtained results in combination with previous data indicate that the Badzhal, Myao-Chain, and Kavalerovo zones were formed through several episodes of the growth and reworking of the Sikhote Alin’ Mesozoic continental crust, which were triggered by underplating. Granitoids and genetically related tin—base metal deposits were formed at final stage. The revealed difference in Sr-Nd composition of the granitoids could be caused by both initial geochemical crustal heterogeneity and the different degree of crustal contamination. Geochemical and isotopic characteristics of the studied granitoids show that they were mainly derived through melting of juvenile metamafic crust, with subordinate contribution of metasedimentary rocks. The ore-bearing magmatic complexes were formed during a change of transform margin setting by accretion of Early Cretaceous terranes of the Sikhote Alin—North Sakhalin orogenic belt. Observed petrogeochemical diversirty of the granitoids from different zones could be caused by variations of sedimentary material, as well as by contamination of magmas by upper crustal material during emplacement, different contribution of mantle source, and diverse mechanisms of mantle-crustal interaction (Khanchuk et al, 2019). Obtained petrochemical, geochemical, and isotopic-geochemical data on the granitoids from the studied zones provide better understanding of diversity of tin-bearing magmatism and conditions of magma generation and evolution in transform margin setting at the continent-ocean boundary.

A mineral assemblage with nisbite NiSb2 and breithauptite NiSb unique for a Mesozoic (Sn)–Pb–Zn vein deposit is found during mineralogical–geochemical study of deep horizons of the Yuzhnoe deposit. In addition to Ni antimonides, this assemblage includes nonstoichiometric Ag sulfoantimonide of variable composition (mineral X), pyrrhotite II, gudmundite II, Ag-bearing chalcopyrite, and stannite II. Nisbite and breithauptite form fine myrmekitic aggregates with pyrrhotite II at the boundary of various early ore minerals. In most cases, these aggregates are confined to the contact between pyrrhotite I and galena. The formation of ultramicroscopic myrmekitic aggregates in galena–sphalerite–pyrrhotite ores is related to ore recrystallization in a thermal fluid field of postore leucogranitic intrusion. New data significantly expand the temperature stability range of assemblages with Ni antimonides.

South Sikhote-Alin metallogenic subprovince (SSAP) is located in the southern part of the Sikhote-Alin orogenic belt. It encompasses more than one hundred well-known deposits and occurrences of boron, tin, lead, and zinc. These deposits have been genetically related to the Late Cretaceous and Paleocene granitoid magmatism. Pb isotope composition was measured using the MC-ICP-MS method in 20 SSAP deposits. Pb isotope ratios (48 samples of galena) vary within narrow limits: Pb-206/Pb-204 ranges from 18.321 to 18.474, Pb-207/Pb-204 - 15.608-15.655, and Pb-208/Pb-204 38.601-38.796. The high degree of homogeneity of the Pb isotope composition and absence of correlations between the lead isotope characteristics of the deposits, on the one hand, and the age and type of ore mineralization, on the other, indicate the presence of a regional uniform Pb source for all the SSAP deposits. The results of Pb-Pb studies of the different rocks of the SSAP suggest that the source was most likely the Mesozoic sedimentary sequences of the Sikhote-Alin accretionary complexes. In turn, individual lead isotope characteristics of the SSAP deposits are caused by varibale contribution of mantle source to the overall balance of lead.

The article presents the history of the development and the current state of tin mining industry in Primorye Region and its leading ore district. The main features of tin mineralization are characterized by examples of some typical deposits. In the description of the deposits, the authors focused on the ore composition determining their commercial value as well as on prognostic estimates. It is shown that the revival of regional tin mining industry is associated with polymetallic state of ores in the prevailing cassiterite-sulfide deposits, in which tin exists with other economically important elements such as Zn, Cu, Ag, Pb, In, and Au. The article provides a detailed description for the Arsenyevskoe deposit. With its considerable reserves of tin and a unique combination of diverse mineralization, this deposit is considered here as a geological object that reflects main features of metallogeny of tin in Primorye. A brief outline is given to the Iskra tin deposit, the last of the discovered (1989) and exploited (1992–2001) deposits in Primorye.

With a view to reveal special characteristics of the transition stage from granite crystallization to rare-metal ore deposition it is studied Badzhal tin-bearing magmatic-fluid system of eponymously-named volcano-plutonic zone of the Middle Priamyrie. For that end the detail research of melt, fluid-melt and fluid inclusions and oxygen isotopes from minerals of granitoids from Verkne-Urmi massif from Badzhal volcano-plutonic zone and also minerals of Sn-W deposits Pravo-Urmi and Blizhnee have been carried out. The formation of greisens and hydrothermal veins were caused by the development of the integrated system associating with establishing of Verkne-Urmi granite massif which is one of a dome fold of Badzhal cryptobatholith. For the first time for tin deposits it has been followed up the transition from the magmatic phase of granite crystallization to the hydrothermal ore formation stage and the evolution of magmatic fluid from its separation from magmatic melt to Sn-W ore deposition. The direct evidence of tin-bearing fluid separation under melt crystallization is combined fluid-melt inclusions. Glass composition in inclusions shows that granites and granite-porphyry were crystallizing from acid and from limited to high-aluminous melts, that is value ASI changes from 0.95 to 1.33 and a content of alkalies varies from 6.02 up to 9.02 mass.%. Cl and F concentrations in glasses are according 0.03–0.14 and 0.14–0.44 mass.% and turned out to be higher of same in the total composition of rocks (0.02 and 0.05–0.13 mass.% in accordance). These differences indicate that Cl and F could be separated from granite melt under its crystallization and degasation. H2O content made from total deficiency electron microprobe analysis is 8–11 mass.%. This evaluation was made inclusive of a probable effect of “Na loss” (Nielsen, Sigurdson, 1981) under aqueous glass crystallization. Considering a high error of a such estimation (Devine et al., 1995), it should take to obtained values as a very approximate evaluation and consider that examined melts contained about 9,5–10,0 mass.% of H2O. The results of melt inclusion examination show that at any rate a part of melt forming magmatic rocks of Badzhal Ore Magmatic System are crystallizing at about T = 650 °C. These melts were acid, limited fluoride and meta- and high aluminous. The reason of low temperatures of its crystallization are likely a high pressure of aqua and also a increased content of F. Most likely that examined inclusions characterize the final stage of establishing of the massif, herewith at the system crystals, residual liquor and magmatic fluid phase coexist. The fluid from which greisens of Pravo-Urmi deposit formed is similar in properties to the supercritical fluid absorbing by magmatic minerals. The salinity of this fluid varying from ~9 to 12 mass.% equiv. NaCl, maximal T = 550 °C (with consideration for the temperature correction of T gom on a pressure ~1 кbar) are similar to such of magmatic fluid, which permit to connect its origin with pluton cooling. The formation of greisens and quartz-topaz veins of Pravo-Urmi deposit is related to fall of temperature of magmatic fluid from 550–450 up to 480–380 °C. The evolution of fluid deposited quartz-cassiterite veins of Blizhnee deposit, which based upon oxygen isotope composition (d18ОН2О ≈ 8.5‰) also separated from magma, was going at more subsurface conditions under much lesser pressure. That led to the gas separation of a fluid with salinity ~13 mass.% equa. NaCl under T = 420–340 °C on thin low salinity vapour and brine with concentration 33.5–37.4 mass.% equiv. NaCl. The research of oxygen isotope system testifies that oxygen isotope composition of ore-forming fluid controlled by equilibrium with granites at wide interval tempera­tures (from ~700 °С up to the beginning of greisen crystallization). Correspondence of measured and calculation data of the offered model indicates that the considerable volume of external fluid with other isotope characteristics which did not reach the isotope equilibrium with Verkhne-Urmi massif did not come into the magmatic isotope system. The discovered differences of physico-chemical conditions for two studied deposits are not “critical” and support an idea about their formation as the single magmatic-fluid system.

The article presents the history of the development and the current state of tin mining industry in Primorye Region and its leading ore district. The main features of tin mineralization are characterized by examples of some typical deposits. In the description of the deposits, the authors focused on the ore composition determining their commercial value as well as on prognostic estimates. It is shown that the revival of regional tin mining industry is associated with polymetallic state of ores in the prevailing cassiterite-sulfide deposits, in which tin exists with other economically important elements such as Zn, Cu, Ag, Pb, In, and Au. The article provides a detailed description for the Arsenyevskoe deposit. With its considerable reserves of tin and a unique combination of diverse mineralization, this deposit is considered here as a geological object that reflects main features of metallogeny of tin in Primorye. A brief outline is given to the Iskra tin deposit, the last of the discovered (1989) and exploited (1992–2001) deposits in Primorye.

С целью выяснения особенностей переходной стадии от кристаллизации гранитов к отложению редкометальных руд изучена Баджальская оловоносная магматогенно-флюидная система одноименной вулкано-плутонической зоны среднего Приамурья. Для этого проведено детальное исследование расплавных, флюидно-расплавных и флюидных включений и изотопного состава кислорода минералов гранитоидов Верхнеурмийского массива Баджальской вулкано-плутонической зоны и минералов Sn-W руд месторождений Правоурмийское и Ближнее. Образование грейзенов и гидротермальных жил Правоурмийского и Ближнего месторождений происходило в результате развития единой магматогенно-флюидной системы, связанной со становлением Верхнеурмийского массива гранитов – одного из куполов Баджальского криптобатолита. Впервые для оловорудных месторождений прослежены переход от магматической фазы кристаллизации гранитов к гидротермальной стадии рудообразования и эволюция магматогенного флюида от его отделения от магматического расплава к отложению Sn-W руд. Прямым доказательством отделения оловоносного флюида при кристаллизации магмы служат комбинированные флюидно-расплавные включения. Состав стекол в них указывает на то, что граниты и гранит-порфиры массива кристаллизовались из кислых от умеренно- до высокоглиноземистых расплавов, значения ASI в которых изменяются от 0.95 до 1.33, а содержание щелочей варьирует от 6.02 до 9.02 мас.%. Концентрации Cl и F в стеклах составили соответственно 0.03–0.14 и 0.14–0.44 мас.% и оказались выше таковых в валовом составе пород (0.02 и 0.05–0.13 мас.% соответственно). Эти различия указывают, что хлор и фтор могли быть удалены из гранитного расплава при его кристаллизации и дегазации. Содержание H 2 O, определенное по недостатку суммы микрозондовых анализов, составило 8–11 мас.%. Это определение было сделано с учетом возможного эффекта “потери натрия” (Nielsen, Sigurdson, 1981) при анализе водосодержащих стекол. Учитывая высокую погрешность такого определения (Devine et al. , 1995), к полученным величинам следует относиться как к очень приблизительной оценке и считать, что изученные расплавы содержали около 9.5–10.0 мас.% воды. Результаты исследования расплавных включений показывают, что по крайней мере часть расплава, формировавшего магматические породы Баджальской РМС, кристаллизовалась при температурах около 650 °С. Эти расплавы по составу были кислыми, умеренно фтористыми и мета- и высокоглиноземистыми. Причиной низких температур их кристаллизации, по-видимому, являются высокое давление воды, а также повышенное содержание фтора. Наиболее вероятно, что изученные включения характеризуют заключительную стадию становления массива, на которой в системе ­сосуществуют кристаллы, остаточный расплав и магматогенная флюидная фаза. Флюид, из которого образовались грейзены Правоурмийского месторождения, очень близок по своим свойствам к надкритическому флюиду, захваченному магматическими минералами. Его соленость, изменяющаяся от ~9 до 12 мас.% эквивалентных NaCl, а максимальные температуры 550 °С (с учетом коррекции температур их гомогенизации на давление ~1 кбар) близки к таковым магматогенного флюида, что позволяет связать его происхождение с остыванием гранитного плутона. Образование грейзенов и кварц-касситерит-топазовых жил Правоурмийского месторождения связано с понижением температуры магматогенного флюида от 550–450 до 480–380 °С. Эволюция флюида, отложившего кварц-касситеритовые жилы Ближнего месторождения, который судя по изотопному составу кислорода (d 18 О Н2О ≈ 8.5‰) также отделился от магмы, протекала в более приповерхностных условиях при значительно меньших давлениях. Это привело к тому, что флюид с соленостью ~13 мас.% эквивалентных NaCl при температурах 420–340 °С претерпел фазовую сепарацию на малоплотный низкосоленый пар и рассол с концентрацией 33.5–37.4 мас.% эквивалентных NaCl. Изучение изотопной системы кислорода свидетельствует, что изотопный состав кислорода рудообразующего флюида контролировался равновесием с гранитами в широком интервале температуры (от ~700 °С до начала кристаллизации грейзенов). Соответствие измеренных и расчетных данных предложенной модели указывает на то, что в магматогенно-флюидную систему не поступило значительных объемов внешнего флюида с иными изотопными характеристиками, который не достиг изотопного равновесия с Верхнеурмийскими гранитами. Выявленные различия физико-химических условий двух изученных месторождений не являются “критическими” и подтверждают мнение о формировании их в составе единой магматогенно-флюидной системы.

В статье дана краткая характеристика типовых оловорудных месторождений Фурмановского рудного района Приморского края.Приводятся сведения о географическом

Detailed geological observations and analytical studies make it possible to distinguish two groups of fluid-explosion breccias (FEB) in the Vysokogorskoe tin deposit of the Kavalerovo ore district. These breccias are assumed to be related to different stages of geological (geodynamic) evolution and played different roles in ore formation. The earlier breccias (79–69 Ma), which were altered by boron metasomatism and subsequent main tin mineralization, were most probably formed at the Cretaceous subduction stage. The later breccias (55–51 Ma) are syngenetic to the dacite (rhyolite) porphyry dikes of the Paleocene–Eocene transform stage. They were formed after precipitation of the majority of the cassiterite, but prior to the latest quartz–fluorite–carbonate stage of ore formation. According to the Sillitoe classification, the explosion breccias of the Vysokogorskoe deposit correspond to a magmatic–hydrothermal genetic type. They are characterized by multiple brecciation and intersection by small bodies of porphyritic rhyolites.

The increased demand for indium has made it necessary to revise prospects of In-bearing tin ore deposits in the Russian Far East on the basis of geological data and results of recent analytical methods (X-ray fluorescence with synchrotron radiation, atomic absorption, and ICP-MS). The average In contents in ores of the Tigrinoe and Pravourmiiskoe deposits vary from 55 to 70 ppm, which allows tin ore deposits with Sn‒sulfide mineralization to be considered as quite promising with respect to In production from ores of Russian deposits. By their estimated In reserves, the Tigrinoe and Pravourmiiskoe deposits may be attributed to large ore objects.

The Mesozoic and Cenozoic geological history of NE Asia comprises alternating episodes of subduction or transform strike-slip movement of the oceanic plate along the continental margin of Eurasia. This sequence resulted in the regular generation of granitoid suites that are characterized by different ages, compositions, and tectonic settings. The Hauterivian–Aptian orogenic stage of the Sikhote-Alin, associated with the strike-slip displacement of the early Paleozoic continental blocks, the successive deformation of the Jurassic and Early Cretaceous terranes, and the injection of the earliest S-type granitoids. During late Albian, the area underwent syn-strike-slip compression caused by collision with the Aptian island arc and resulted in the injection of voluminous magmas of calc-alkaline magnesian (S- and I-type) and alkali-calcic ferroan (A-type) granitoids into syn-faulting compressional and extensional basins, respectively. Northwestward to westward movement of the Izanagi Plate resulted in the initiation of frontal subduction of the Paleo-Pacific Plate during the Cenomanian–Maastrichtian. In turn, this resulted in the generation of plateau-forming ignimbrites and their intrusive analogs formed from metaluminous I-type felsic magmas. Paleocene–Eocene magmatism in the Sikhote-Alin area commenced after the termination of subduction in a rifting regime related to strike-slip movement of the oceanic plate relative to the continent. The break-off of the subducted plate and the injection of oceanic asthenospheric material into the subcontinental lithosphere resulted in the eruption of lamproites and fayalite rhyolites, and coeval intrusions of gabbro and alkali feldspar granites (А-type). The A-type granitic-rocks and coeval gabbro–monzonites are considered to be reliable indicators of the transform continental margin geodynamic settings.

The paper considers for the first time the morphology, composition, and conditions of formation of the greisens of the Solnechnoe deposit (Komsomol’sk ore district), a typical cassiterite–silicate assemblage. The greisens are localized in the root parts of the deposit and represent a system of veins and veinlets formed in the contraction fractures of the metasomatically altered roof of the monzogranite intrusion (age of 94–92 Ma). The cassiterite–chlorite–carbonate–muscovite–quartz composition of the greisens with admixture of topaz, fluorite, and apatite reflects the composition of the monzogranites. The greisens are close in age (85.3 Ma on muscovite) to the granitic aplites (80–85 Ma on the whole-rock and biotite) of the final phase of the intrusive magmatism. The fluid regime of their formation differs from that of the economic ores in higher temperature, pressure, and salinity. One distinguishing feature of the greisens is elevated contents of LREE, U, and Th, which are incorporated in the REE fluorcarbonates, thorite, and uranothorite crystallizing together with cassiterite.

Biotite and biotite–amphibole pairs from granitoids of the southern Sikhote-Alin–North Sakhalin orogenic belt are dated by the K–Ar method. The obtained ages are highly consistent with U–Pb zircon data (original and published data). In the zircon (U–Pb)–biotite (K–Ar)–amphibole (K–Ar) triad, the zircon and biotite define close, frequently identical, ages, whereas the amphiboles usually yield younger K–Ar ages, which is inconsistent with the idea of the relative stability of the K–Ar isotope system of amphibole to thermal impact. Our research confirms the existing opinion that the isotope system of biotite is more stable to hydrothermal–metasomatic alteration than that of amphibole. The younger age of amphibole in monzonitic associations is probably caused by the formation of amphibole after pyroxene at the late magmatic and early postmagmatic stages. The obtained results, with allowance for analysis of the reliability of the isotope K–Ar and U–Pb dates on different mineral phases, confirm the idea that the Albian stage played a special role in the geological evolution of the studied region and mark the peak of magmatic activity at 105–95 Ma. According to isotope dates, the Albian–Cenomanian time was a period of simultaneous formation of monzonites and granites in Sikhote-Alin, which is typical of the continent–ocean transform-plate-boundary setting. It is found that the distribution of granitoids of different age is determined by the boundaries of the terranes of orogenic belts.