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The comparison of optical oscillators is used both to determine their spectral characteristics and to perform fundamental research. To describe each individual laser system, it is necessary to compare at least three independent laser oscillators. Three ultrastable lasers with wavelengths of 1140, 1550, and 871 nm located in different laboratories at the Lebedev Physical Institute have been compared. A femtosecond frequency comb has been used to transfer stability between different spectral ranges. A fractional frequency instability has been obtained with the three-cornered hat method and phase noise of each laser has been analyzed. Using this method, it has been shown that the characteristics of the laser system at a wavelength of 871 nm are appropriate to control the quantum state of an optical qubit on a quadrupole transition in an ytterbium ion with a n-atural width of 3.1 Hz.

Ultracold ions provide one of the most promising platforms for quantum computing and make it possible to reach record coherence times, the fidelity of preparation and readout operations, and single- and two-qubit operations. Encoding quantum information in an optical qubit based on the $$^{2}{{S}_{{1/2}}}(F = 0,{{m}_{F}} = 0)$$ → $$^{2}{{D}_{{3/2}}}(F = 2,{{m}_{F}} = 0)$$ quadrupole transition in the 171Yb+ ion at a wavelength of 435.5 nm, which has potential advantages over similar systems in the scaling of the number of qubits and their sensitivity to fluctuations of the magnetic field, is proposed and experimentally studied. The proposed optical qubit in ytterbium is compared to other most widespread types of ion qubits. Experimental results on the implementation of the Pauli-X single-qubit operation are given. The fidelity of the operation is 96% after correction to the error of preparation and readout and is limited by the temperature of the ion.

––Geological, mineralogical, and geochemical studies of copper and gold mineralization in the Bumbat ore district of Mongolia have shown its association with igneous rocks of different ages formed under different geodynamic, geologic, and geochemical conditions. Copper ore occurrences (site 98 and Altan Gadas site) with an age of 518.0 ± 4.9 Ma have similar mineralogical and geochemical features and seem to be related to plagiogranite-porphyry stocks formed at the late island arc stage (524.5 Ma). The ores were deposited from weakly concentrated solutions with a low content of СО2 at 240–230 °С under subsurface conditions. The association of mineralization with plagiogranites, its localization predominantly in veins, and its essentially copper composition, with high contents of Zn, Mn, Ba, and, in some samples, Ag and Bi, permit us to assign this mineralization to the vein quartz–sulfide type. Its commercial value has yet to be assessed. Gold mineralization of the Three Hills and Darvi sites formed later (455.9 ± 4.3 Ma), during the formation of the final granitoid phases at the accretion–collision stage (511–465 Ma). These sites are mineralized crushing zones composed of hydrothermally altered rocks of sericite–quartz composition with veinlet and disseminated (stockwork) sulfide mineralization and gold-bearing quartz veins. The content of gold in the ores varies from tenths to tens of ppm, and its fineness varies from 700 to 1000‰. The ores of both sites have high contents of Cu, Zn, Mn, Ba, and, in places, Mo. Mineralization formed from hydrothermal solutions with TDS = 9.5–12.0 wt.% NaCl eq. at medium temperatures (230–300 °C) under subsurface conditions. The above specific features of gold mineralization are typical of the flank zones of porphyry Cu–(Mo) deposits.

The design of a linear ion Paul trap for quantum-logical operations on ultracold ions with high reliability is developed. The general requirements for the trap are presented, its parameters are optimized, and electric fields are numerically simulated.

We report the results of studying a compact laser system designed for manipulating a quantum state of the optical qubit based on the 2S1/2 → 2D3/2 quadrupole transition in the 171Yb+ ion at a wavelength of 435.5 nm. An emission power of the laser system reaches 500 μW at λ = 435.5 nm and the relative frequency instability of at most 3 × 10−15 is achieved at averaging intervals from 0.5 to 50 s with a subtracted linear frequency drift. The compactness of the developed system makes it possible to employ it in transportable systems including optical clocks.

The Paul ion trap is developed for the use in a compact frequency standard based on a single ytterbium ion. The design features are the use of atomic ovens for compensating for parasitic electric fields and good optical accessibility. The results on trapping and laser cooling of a single 171Yb+ ion are presented. A secular frequency of up to 1.2 MHz has been achieved.

Trapped ions nowadays play an important role in both fundamental science and technical applications. Due to its convenient energy structure, singly charged ytterbium ion is widely used in microwave and optical frequency standards, tests of fundamental theories, and quantum information science. In this paper, we present the results of wavelengths measurements in the 2S1/2→2P1/2 and 2D3/2→3[3/2]1/2 transitions in 170Yb+, 171Yb+, 172Yb+, 174Yb+, and 176Yb+ ions with uncertainties of 50 and 20 MHz, respectively. We reach a factor of three-times improvement in the accuracy with respect to the previously published data, which significantly simplifies the process of initial ion trapping and cooling, in a laser system and an ion trap designed for the YBIS Project aimed for developing a compact and transportable optical clock based on a single 171Yb+ ion.

—The method of quasi-equilibrium directional crystallization was used for experimental modeling of the behavior of noble metals in the presence of Te during the fractional crystallization of Cu- and Ni-rich sulfide magma. The experimental melt contained (mol.%): Fe = 18.5, Ni = 19.1, Cu = 16.7, S = 44.1, and Pt = Pd = Rh = Ir = Ru = Ag = Au = Te = 0.2, i.e., is similar in composition to the massive pentlandite-bornite ores of platinum-copper-nickel deposits of the Noril’sk group. The crystallized sample consists of six primary zones differing in chemical and phase compositions. The main minerals crystallizing from the melt include the following sulfide phases: bornite solid solution (bnss), quaternary solid solution (tss), described earlier in the literature, and three phases (сfpn, cnpn, npn), which we attributed to pentlandite according to their chemical composition. The primary phases crystallized from the melt decay on cooling with the formation of secondary phases. The сfpn, cnpn, and tss phases decay completely, and the npn and bnss phases, partly. As a result, secondary zoning forms in the sample. Formation of drop-like inclusions of telluride melt was observed in the end zone of the ingot. The obtained data show that pentlandites and tss are the main high-temperature concentrators of PGE, with each of the macrophases showing specific PGE accumulation. Eight types of impurity phases have been detected. They form by different mechanisms: crystallization from sulfide melt of refractory compounds, deposition from telluride melt, and formation through complete or partial decay of primary macro- and microphases. A scheme of the zonal structure of the crystallized sample and the evolution of the phase composition during fractional crystallization has been constructed. It clearly demonstrates the intricate formation of primary and secondary major-component and impurity zonings and can be used to explain the nature of the zoned structure of massive PGE-bearing pentlandite–bornite orebodies.

The sideband cooling method and its implementation on the Raman transition of 25Mg+ is presented. The process is numerically simulated under the conditions of experiments at the Lebedev Physical Institute. Laser pulse parameters are optimized to achieve the minimum average vibrational number over the times of Raman cooling of the order of several milliseconds.

The schematic diagram of the compact transportable optical frequency standard based on the quadrupole transition in a single 171Yb+ ion with a relative instability at the levelx of 5 · 10−16, less than 1m3 in volume and less than 300 kg in weight is presented. The ionic trap and laser systems are described. Trapping and laser cooling of the 174Yb+ ion are experimentally demonstrated.

We propose a method for EIT ground state cooling of 171Yb+ ion, which involves three light fields with detuning on a MHz scale. The steady-state mean vibrational quantum number is calculated to be less than 0.005. Efficient cooling is achievable in a motional-mode frequency range of 2π · (1.5 ± 0.5 MHz).

We consider the mineralogical and geochemical features of the rocks of the Inagli dunite–clinopyroxenite–shonkinite massif with platinum–chromite and unique jewelry Cr-diopside mineralization, which is a reference object of concentric zonal complexes. The massif rocks, from dunites to pulaskites, including peridotites, clinopyroxenites, shonkinites, and melanocratic alkali syenites, form a single continuous comagmatic series. This is confirmed by a clear dependence of the compositions of olivine, pyroxene, phlogopites, and Cr-spinels on the MgO content of the rocks and on the behavior of trace elements in them. The similar compositions of pyroxenes and trace-element patterns of clinopyroxenite rocks and Cr-diopsidite veins indicate a genetic similarity of these rocks. The age and mineralogical and geochemical compositions of the rocks and the geologic and morphological features of the intrusion prove that the Inagli massif formed from high-K picritoid melts, which underwent gradual decompression solidification during the ascent and formed a cylindrical diapir-like body at the subsurface level in the Early Cretaceous. The new portions of differentiates supplied from the lower horizons of the magma column determined the complex composition of the massif: It has a concentric zonal structure cut by numerous radial-circular vein bodies of pegmatites and pure anchimonomineral rocks (Cr-diopsidites), in places, of jewelry quality.

The paper presents new isotope geochronological data for several mineral deposits, ore occurrences, and related igneous bodies (plutons and dikes) in the Verkhoyansk–Kolyma folded area, eastern Yakutia. Twenty-one 40Ar/39Ar mica and four U–Pb zircon dates provide the first age constraints on key metallogenic units in the area. The dating results allow correlation between tectonic, magmatic, and metallogenic events. The sampled mineral deposits within the Adycha–Taryn fault zone in the southeastern Verkhoyansk–Chersky orogen apparently formed at the Jurassic–Cretaceous boundary during the final phase of the collision between the Siberian (North Asian) craton and the Kolyma–Omolon microcontinent (Kupol’noe deposit and the early metallogenic pulse of the Malotarynskoe deposit, ~ 143–144 Ma) and in the latest Early Cretaceous, in the beginning of the orogen collapse (Tallalakh and Dora-Pil’ deposits and the Malotarynskoe late metallogenic pulse, ~ 126 Ma). According to the suggested new classification of metallogenic units, these deposits belong to the Late Jurassic–Early Cretaceous Yana–Kolyma metallogenic belt. The Kyuchus deposit (~ 106 Ma), the Deputatsky ore cluster (~ 106–113 Ma), and the Khotoidokh deposit (~ 116 Ma) in the northern Verkhoyansk–Kolyma folded area belong to the North Verkhoyansk metallogenic belt. Their origin was associated with accretional and collisional processes that produced the Novosibirsk–Chukotka orogen in the middle Cretaceous. The Mangazeya ore cluster (~ 100 Ma, Early–Late Cretaceous boundary) in the southwestern end of the North Tirekhtyakh magmatic transverse belt belongs to the West Verkhoyansk metallogenic belt. The Nezhdaninskoe, Zaderzhnoe, Kurum, and Kuta deposits of the South Verkhoyansk area (~ 125–120 and ~ 100–95 Ma) can be joined into a single Verkhoyansk–Okhotsk metallogenic belt. The belt resulted from accretion and collision along the East Asian active continental margin and the related formation of the South Verkhoyansk orogen in the Early Cretaceous.

The results of study of the chemical and phase compositions of three Ag-, Au-, platinum group element-, As-, Bi-, and Te-bearing samples, which are the product of directed crystallization of the Cu–Fe–Ni sulfide melt, are presented. One sample contained only metals, the second one was additionally doped with As, and the third one was enhanced in As, Bi, and Te. The mechanism of formation of the minerals of the platinum group metals during fractionation crystallization of multicomponent sulfide melts was proposed on the basis of interpretation of experimental data.

Using modern thermobarogeochemical methods (thermo- and cryometry, Raman spectroscopy, and LA–ICP-MS), we studied fluid inclusions in quartz from ores formed at the quartz–fluorite, pyrite–chalcopyrite, pyrite–molybdenite, and polysulfide stages of evolution of the Samolazovskoe gold deposit. We have established the fluid regime of the ore formation processes, the gas and liquid composition, main solid phases (metal sulfates, carbonates, and chlorides), homogenization temperatures of the inclusions, and the eutectic temperatures of their solutions. The obtained data helped to estimate the fluid temperatures during the formation of ores at each stage and to determine the contents of major salt components. Based on the substance solubility values given in the reference-book by V.B. Kogan, we have first constructed a phase diagram of the system Na2SO4–NaHCO3–H2O (Na2SO4 < 35 wt.%) at temperatures below 40 °C. The metal contents and geochemical specifics of solutions at each stage of the ore formation were determined by LA–ICP-MS. At the quartz–fluorite stage, the solutions were enriched in B, V, Co, Ni, Zn, As, Te, Cs, Ba, and Mg; at the pyrite–molybdenite stage, they had high concentrations of Ti, Ni, Nb, and Mo; and at the polysulfide stage, the solutions were rich in Ca, As, Pb, Sb, Te, Ag, Rb, Ba, and Sr. Native sulfur found along with sulfate and sulfide sulfur in the inclusions impelled us to study the sulfur isotope composition. The research has shown a light sulfur isotope composition (δ34S = –2.5 to –13.4‰). We believe that sulfide sulfur in the Samolazovskoe deposit formed from a fluid during high-temperature (> 500–700 °C) sulfate reduction.

The T,X-parameters of the main ore-forming stages of the Rogovik epithermal gold-silver deposit (northeastern Russia) were determined using microthermometric techniques on fluid inclusion assemblages. On the basis of these data we carried out thermodynamic calculations that model the formation conditions of three types of ore mineral assemblages: gold-silver – at the early volcanic stage, silver-polymetallic and silver-gold-polymetallic – at the late volcanoplutonic stage. The silver-gold-polymetallic mineralization is located at the sites where silver-polymetallic and gold-silver zones overlap. The calculations were made using the “Selektor-C” software within a complex geochemical multicomponent system. Several scenarios of formation of gold-silver mineralization at an early volcanic stage were considered: 1) boiling of a hydrothermal solution; 2) interaction of residual aqueous solution with host rocks; 3) mixing of an ore-bearing gas phase with meteoric waters. For the late volcanoplutonic stage, we modeled formation of “silver mineralization” using an ore-forming solution genetically related to a deep-seated granite massif and its interaction with host rocks and gold-silver zones of early volcanic stage. These physicochemical models substantially improve our understanding of formation of the three types of mineral assemblages at the Rogovik deposit and can be applied to other epithermal deposits with similar mineralization styles.

A linear quadrupole Paul trap is fabricated for capturing magnesium and aluminium ions. An experimental cycle performed has demonstrated ion capture and holding in a trap with an average ion lifetime of . Modelling of ion dynamics in the trap shows that the main mechanism responsible for losses of hot ions is multiparticle interaction, which results in that a kinetic energy of some ions increases and they leave the trapping zone. This mechanism is completely suppressed if ions are cooled. Another mechanism is the charge exchange; however, it is not substantial at a high average energy of ions produced in the result of an electron impact. Parameters of the trap allow one to perform precision spectroscopic measurements and to control ion quantum states.

Thermodynamic calculations using the HCh software were made for mineral equilibriums including REEs in the fluoride–sulfide–chloride–carbonate–sulfate–system in the presence of Na, Ca, and P with fluids of various acidities–alkalinities [11]. The obtained thermodynamic characteristics of thenardite allowed us to carry out the calculations for this phase under complicated hydrothermal conditions simulating the presence of oxidized fluids at 500–100°C and 2000–125 bar. Among other solid phases, REEs–fluorite, monazite, and REE–F–apatite were formed as CaF2–(Ln,Y)F3, LnPO4, and Ca5(PO4)3F–(Ln,Y)3(PO4)3 ideal solid solutions, respectively, where Ln is La, Ce, Pr, Nd, Sm, Eu, and Gd. Xenotime, anhydrite, elemental sulfur, and calcite were found as well.

Fe-rich carbonatites with a mineral assemblage of ankerite-calcite or siderite are widespread in southern Siberia, Russia. The siderite carbonatites are associated with F-Ba-Sr-REE mineralization and have a 40Ar/39Ar age of 117.2 ± 1.3 Ma. Melt and fluid inclusions suggest that the carbonatites formed from volatile-rich alkali- and chloride-bearing carbonate melts. Ankerite-calcite carbonatites formed from carbonatite melt at a temperature of more than 790 °C. The ferrocarbonatites (the second phase of carbonatite intrusion) formed from a sulfate-carbonate-chloride fluid phase (brine-melt) at >650 °C and ≥360 MPa. The brine-melt fluid phase had high concentrations of Fe and LREEs. A subsequent hydrothermal overprint contributed to the formation of economically important barite-Sr-fluorite-REE mineralization in polymict siderite breccia.

Based on results of study of fluid inclusions, we have established the specific fluid regime of formation of the Kalguty Mo–W(Be) deposit (Gorny Altai). Using classical thermobarogeochemistry (cryo- and thermometry) and modern microprobing methods (Raman spectroscopy and LA-ICP-MS), we studied fluid inclusions in quartz of quartz–wolframite veins (ore formation stage I), specific “quartz core” (quartz lens), and pyrite-chalcopyrite-molybdenite paragenesis (ore formation stage II). The results of study show that the quartz–wolframite veins of the Kalguty deposit formed with the participation of reduced W-Sb-bearing fluids with a salt content of up to 5.9 wt.%. Their gas phase consisted of CO2, N2, and CH4. Formation of pyrite-chalcopyrite-molybdenite mineralization involved oxidized hot (530–420 °C) fluids with the average salt content of 9.3 wt.%. Their gas phase was of high density (up to 0.55) and consisted of CO2, N2, and H2S. The pressure of the mineral-forming environment varied from 50 to 25 MPa. The fluids contained Cu, Mo, Bi, and S. The productive greisen-vein Mo–W(Be) mineralization of the Kalguty deposit resulted from the superposition of greisen molybdenite-chalcopyrite mineralization on parageneses of earlier formed quartz-wolframite veins. Oxidized metal-bearing fluids that formed the Mo mineralization of the Kalguty deposit have high contents of S and are geochemical analogs of magmatic metal-bearing ore-forming fluids of the Central Aldan porphyry Cu-Au-Mo deposits, which are genetically related to alkaline massifs. This suggests the significant influence of the mantle source on the formation of the Kalguty rare-metal ore-magmatic system. The same is evidenced from the sulfur isotope composition of chalcopyrite, molybdenite, and pyrite from ore parageneses, falling in the narrow range of δ34S‰ from –1.2 to +2.9 corresponding to the isotope composition of mantle sulfur.

The Ta Nang gold deposit is localized in Middle Jurassic black shales. The ore zone is a series of layer-by-layer crush zones and zones of hydrothermal rock alteration, ≤10 m in thickness and >2 km in length. It consists of quartz–sulfide veins, sulfidized black shales, and their hydrothermally altered varieties. Sulfide mineralization occurs as two assemblages: early pyrite–arsenopyrite and late chalcopyrite–sphalerite– galena. The pyrite–arsenopyrite assemblage is composed of different morphogenetic varieties. Coarse-crystalline arsenopyrite and pyrite aggregates and metacrystals of different orientations, 0.1 to 10 mm in size, are the most widespread. The chalcopyrite–sphalerite–galena assemblage is scarce. Along with the main ore minerals, it includes more rare minerals: pyrrhotite, lead sulfosalts (tsugaruite), and gold, which form a spatial assemblage with the main minerals or small inclusions in them. Gold occurs mainly as fine dissemination in cracks in pyrite, arsenopyrite, chalcopyrite, and quartz. Gold content in sulfidized carbonaceous shales is no more than tenths of ppm, averaging 0.38 ppm. This content in the quartz veins is considerably higher, averaging 3.92 ppm. Silver contents in the shales and quartz veins are similar and equal to 2.68 and 5.30 ppm, respectively. Also, the sulfidized rocks and veins have elevated contents of Fe, As, Pb, Zn, Cu, Cd, Ni, and Co; most of these elements (Fe, As, Pb, Zn, and Cu) make up their own sulfide minerals, and the others are trace elements. According to 39Ar/40Ar dating of sericite from the quartz–sulfide veins, their age is 129.3 ± 5.6 Ma, which is close to the age of the Cretaceous granite intrusions of the Deo Ca complex. These veins formed from moderately strong solutions (11.7–6.4 wt.% NaCl equiv) with the CH4 + N2 + CO2 gas phase at 340–130 °C. Judging from the S isotope composition (δ34S = 1.6–4.3‰), predominantly deep-seated endogenic sulfur participated in the formation of ore sulfide associations. Analysis of the distribution of gold shows that it was deposited together with sulfide minerals (galena, sphalerite, and chalcopyrite) at a later stage.

Major and trace elements and whole rock Sr–Nd isotope data of Late Permian silicic plutonic and volcanic rocks from the Phan Si Pan–Tu Le region in NW Vietnam were collected in order to establish their petrogenetic relationship with the magmatic rocks of the Song Da zone (NW Vietnam) and the alkaline silicic rocks of the Panxi area of the Emeishan large igneous province (ELIP) in SW China. The granites and rhyolites have geochemical characteristics of anorogenic granites (e.g. high Fe# and high Ga/Al) and are further subdivided based on mineralogy. The Phu Sa Phin and Muong Hum granites contain sodic to sodic–calcic amphiboles and sodic pyroxene, while the Phan Si Pan granite does not. The Phu Sa Phin and Muong Hum granites occasionally show peralkaline to metaluminous compositions, while the Phan Si Pan granites and the Tu Le rhyolites have metaluminous to peraluminous compositions. The chondrite-normalized REE patterns [(La/Yb)N = 3.6–51.3, (Gd/Yb)N = 1.4–3.4] and the primitive mantle-normalized spidergrams (enrichment in high field strength elements) are similar to those of the Song Da silicic rocks and the Panzhihua and Taihe granites in the Panxi area. Rhyolite-MELTS modeling suggest that the silicic magmas were likely generated by fractionation of the Song Da high-Ti basalts. The eNd(t) values range from weakly negative to moderately positive values (−2.2 to +2.2), suggesting the silicic rocks may be assimilated by basement rocks during magma emplacement. Permian magmatic rocks in the Phan Si Pan–Tu Le region are petrologically, geochemically and geochronologically comparable to those of the inner zone of ELIP. Although Permian lithospheric mantle and lower crustal structure of the Phan Si Pan–Tu Le region may be destroyed by a lithospheric removal in response to Cenozoic India–Eurasia collision, our results along with recent geophysical analyses in NW Vietnam suggest that the upper to middle crust of Phan Si Pan–Tu Le region represent a remnant upper to middle crust of inner zone of ELIP.

The Ob-Zaisan folded zone is a fragment of a single structure composed of Paleozoic sedimentary and volcanogenic rocks (mainly black shale), which was formed at the margin of the Siberian continent and features a common set of magmatic complexes and mineral systems. However, there are some differences that determine the specific geological and metallogenic features of the Irtysh-Zaisan and Kolyvan-Tomsk fragments of the Ob-Zaisan folded zone. In the gold deposits of the West Kalba and Kolyvan-Tomsk auriferous belt, the main gold-sulfide mineralization is controlled by zones of shearing and dynamic metamorphism in carbonaceous carbonate-terrigenous rocks. This type of mineralization was formed in tectonic blocks in a compressional setting. Antimony mineralization is characterized by brecciated textures and the vein-like morphology of ore bodies, reflecting extensional tectonics. At some deposits (Zherek, Mirazh, Dalny), Sb mineralization is spatially separated from the main gold-sulfide ores and shows cross-cutting relations to the principal ore-controlling structures. In other gold deposits, stibnite is spatially associated with disseminated gold-sulfide ores and forms mineral assemblages with Ni, Co, Au, Pb, and Fe (Alimbet, Zhanan, Legostaevskoe, Semiluzhenskoe, and Kamenskoe deposits). This study reveals no direct correlation between Au and Sb in gold-sulfide ores of these deposits. SEM analysis indicated the absence of free gold in stibnite veins. However, atomic absorption and electron microprobe analysis indicated the presence of “invisible gold” from a few ppm to several tens of ppm in the stibnite. High gold contents in the gold-sulfide ores overprinted by antimony mineralization (Suzdalskoe, Zhanan, and Legostaevskoe deposits) can be explained by the processes of regeneration and redeposition. The results of microstructural observations, isotope geochronology, studies of mineral assemblages and fluid inclusions in the ores from gold deposits of the Ob-Zaisan folded zone suggest that antimony mineralization was formed at gold-polysulfide stage, which was separated from the early ore pyrite-arsenopyrite stage by a 30 Ma time gap. It can be assumed that the essentially stibnite mineralization was formed at a separate stage and was separated from the gold-polysulfide mineralization by a 7 Ma interval of tectonic activity. Our Ar-Ar data on sericite from ore samples, combined with U-Pb data on zircons from igneous rocks and previous data from the literature show that there were two major stages of ore formation: the Early Permian (282-270 Ma) and the Early Triassic (250-240 Ma). Most researchers suggest that these stages of mineralization can be related to the epochs of intraplate magmatism that led to the formation of the Tarim (280 Ma) and Siberian (250 Ma) large igneous provinces. These global geological events are generally connected with the influence of Tarim and Siberian mantle plumes.

The spatial coexistence and synchronous formation of magmatogene porphyry Cu–Mo mineralization and epithermal gold mineralization are due to the genetic relationship between their formation processes. This relationship might be due to the generation of metal-bearing fluids of different geochemical compositions by the porphyry ore-magmatic system, which then participate in the formation of magmatogene porphyry Cu–Mo(Au) and associated epithermal gold deposits. Synthesis of fluid inclusions in quartz was performed for experimental study of the behavior of Cu, Mo, W, Sn, Au, As, Sb, Te, Ag, and Bi in heterophase fluids similar in composition and aggregate state to natural ore-forming fluids of porphyry Cu–Mo(Au) deposits. We have established that at 700 ºC, a pressure decrease from 117 to 106 MPa leads to a significant enrichment of the gas phase of heterophase chloride fluid with Au, As, Sb, and Bi. The heterophase state of carbonate–chloride–sulfate fluids is observed at 600 ºC and 100–90 MPa. It characterizes the highly concentrated liquid carbonate–sulfide phase–liquid chloride phase–low-density gas phase equilibrium. A decrease in the pressure of heterophase carbonate–chloride–sulfate fluid leads to a noticeable enrichment of its chloride phase with Cu, Mo, Fe, W, Ag, Sn, Sb, and Zn relative to the carbonate–sulfate phase. The processes of redistribution of ore elements between the phases of heterophase fluids can be considered a model of generation of metal-bearing chloride fluids, which occurs in nature during the formation of porphyry Cu–Mo(Au) deposits, as well as a model of generation of gas fluids supplying Au, Te, As, and other ore elements to the place of formation of epithermal Au–Cu and Au–Ag mineralization. © 2015, V.S. Sobolev IGM, Siberian Branch of the RAS. Published by Elsevier B.V. All rights reserved.

The authors have studied melt-fluid and fluid inclusions in quartz and fluorite of sideritic and ankerite-calcitic carbonatites of the Karasug ore field, as well as melt inclusions in apatite from granosyenites. The content of salt and fluid components in brine-melt inclusions was evaluated on the basis of the thermodynamic data, the calculations of volumes and densities of the solid phases, a solution of about 50% concentration, and the gas phase of the inclusions, as well as the results of the LA-ICP-MS analysis. The content of salt phases, the solution, and the gas phase amounted to 85–70, 10–25, and about 5% of the inclusion substance, respectively. The total percentage of salt and fluid components (H2O and CO2) amounted to 90–80 and 10–20 wt %, respectively. The fraction of a carbonate constituent in the inclusions was as high as 45–50% and over in ankerite-calcite carbonatites and about 15 wt % in sideritic carbonatites. The 117.2 ± 1.3 Ma age of these carbonatites by 40Ar/39Ar, along with other datings for this area, shows that their formation was associated with a manifestation of the Cretaceous alkaline-mafic magmatism (117–120 Ma). The presented model of the formation of carbonatites is in agreement with the sequence of the development of magmatic processes and mineralization in this area. The model is also confirmed by the results of the studies of melt and fluid inclusions in minerals.

This paper presents the results of geochronological studies of the Tomtor alkaline-ultramafic pluton, one of the largest Nb, Y, Sc, and TR deposits. A new scheme of its magmatism is given. The current K-Ar and Rb-Sr ages of different igneous rocks of the Tomtor pluton range from 800 to 250 Ma [Zaitsev et al., 1992; Frolov et al., 2003]. Such dispersion is probably related to the intense carbonatization of the rocks. The U-Pb zircon and 40Ar/39Ar mica ages indicate two stages of the formation of the pluton (700 and 400 Ma), which agrees well with the age of cycles of rift-related tectonogenesis of the Siberian platform.

We demonstrate a simple nonisotope-selective method for ion trap loading, which is based on the irradiation of trap electrodes precoated with materials with a low work function by a light-emitting diode (LED). Photoelectrons emitted from the electrode surface and accelerated in the trap electric field ionize the atomic beam inside the trap, which results in the trap loading. We studied Y2O3 and Mg coatings for the trap electrodes and experimentally demonstrated trapping of single 24Mg+ ions as well as large ion crystals composed of up to 103 particles using a 400 nm LED. This method can be readily implemented in a variety of applications where simplicity, compactness, and robustness are critical, such as in portable ion frequency standards and commercial ion-based devices, for example. Possible modifications of this technique aimed for selective loading, reduction of induced electric stray fields, and getting rid of atomic oven are also discussed.

This paper presents new data derived from field sampling and from a thorough description of lamprophyres located in southeastern Altai and northwestern Mongolia in terms of their mineralogy, textures, and chemical composition. The swarms of alkaline mafic dikes in the area coexist with granosyenite-monzodiorite and gabbro-dolerite intrusions and spatially coincide with an ore district of Sb-Hg, Ag-Sb, Ni-Co-As, Cu-Mo-W, and CaF2 hydrothermal mineralization. All lamprophyres belong to the Early Mesozoic Chuya complex formed in an intracontinental enviroment. Their distribution and orientation is controlled by two large fault zones. The Chuya dikes were investigated at two localities, namely, Yustyd and South-Chuya. The Yustyd lamprophyres intrude Middle-Upper Devonian black shale of the Yustyd depression. At South Chuya, lamprophyres, together with the Tarkhata granosyenite-monzodiorite complex, are hosted by Cambrian and Ordovician metamorphic rocks of the South-Chuya Range. Ar-Ar (phlogopite) and U-Pb (SHRIMP, zircon) ages of the lamprophyre dikes indicate long and continuous period of the formation of the Chuya complex (250-235 Ma). Major- and trace-element compositions of the lamprophyres from both localities and of the syenite indicate their origin from the same magma source. The textures and structures of the lamprophyre and plutonic rocks, their mineral assemblages and the chemistry of the rock-forming minerals provide clues to the evolution of the parental alkaline mafic magma and fluid regime.

The Suzdal gold-sulfide deposit is situated in the northwestern part of the West Kalba gold belt in Eastern Kazakhstan and belongs to the genetic type of stringer-disseminated mineralized zones hosted in the Lower Carboniferous black-shale volcanic-carbonate-terrigenous sequences. Mineralization is controlled by the NE-trending Suzdal Fault. In the north, the deposit borders on the Early Triassic Semeytau volcanic-plutonic structure. Mineralization is superposed on the Late Paleozoic complex of metadolerite and quartz porphyry dikes. Ore deposition was a long-term process comprising four stages. The first stage was related to deposition of slightly auriferous pyrite syngenetic to host rocks. The second stage is characterized by formation of the first productive (with invisible gold) fine-acicular arsenopyrite mineralization accompanied by sericitization and localized in the tectonic zone. The stockwork ore with pocket-disseminated base-metal mineralization and free microscopic gold of the third stage is hosted in silicified rocks. The ore formation has been completed by quartz-stibnite veins superposed on all preceding types of mineralization. According to Ar/Ar dating of sericite, a chronological gap between the second and the third stages is estimated at 33 Ma. The deposit is an example of polygenetic and multistage mineralization.

Cezonoic magmatic activities in the Phan Si Pan Uplift and Red River Shear Zone, northwest Viet Nam are related with India – Eurasian collision.

Late Permian mafic-ultramafic volcanic and sub-volcanic rocks in the Song Đa Rift include four different associations in terms of low-Ti and high-Ti types. Low-Ti, high-Mg volcanic and sub-volcanic rocks are composed of komatiite, komatiitic basalt and basalt and are divided into three groups according to their petrological and geochemical features. Chemical composition of rocks of the komatiite-basalt association is alkali-low (but rather Na-high), very Ti-low, varying from Al-high komatiite to Al-low basalt. They are characterized by high content of Mg, Al, Ni, Co, Cu and Cr, and low of Ti, Fe, Na, K, P, Rb, Ba, Sr, Nb, Ta, Nd, Hf, Zr and REE. In general, based on geochemical and isotopic characteristics the Song Đa mafic-ultramafic rocks of the komatiite-basalt association may be products of a melt derived from depleted mantle suffering the impact of mantle plume. Digital modeling showed that the initial melt composition was correspondent to komatiitic basalt. Eruption ages of the magmas are 257 ± 24 Ma (by Rb/Sr age dating), and 270 ± 21 Ma (by Re/Os age dating).

The Cenozoic mineralization in structures associated with the Red River shear zone (RRSZ) in northern Viet Nam includes the following mineralized ore types TR- (U-Th)-Pb-Zn and TR- (U-Th) –Ba-F, Au-Cu in the Song Da rift zone. The origin of the mineralizations is spatially and (possibly) temporally related to the formation of Paleogene potassic mafic – ultramafic and silisic associations. Molybdenum –precious metals (Mo-W-Cu-Au) in the along with Cu-Au mineralization in the Phan Si Pan uplift are related to Paleogene granitoidic magmatism in the Ye Yen Sun complex. Beside, Cu-(Au – REE) mineralizationsin the Phan Si Pan Uplift are described.

Three mineralization complexes were formed during the Permian – Triassic period in the following order: PGE-Cu-Ni and V-Ti – Fe of magmatic origin; Au – sulfide and Sn – sulfide. The first ore complex including magma-origin Cu-Ni-(Pt) mineralization is related to ultramafic - mafic magmatic differentiation in structures of Song Da, Song Hien rifts (such as Ban Phuc, Ban Khoa, Suoi Cun blocks, etc.) as well as being connected to layered gabbro – peridotite intrusions in folded structures surrounding the Song Chay anticlinoria (such as Nui Chua and Khao Que blocks). Cu-Ni-(PGE)-type mineralization is found in Ta Khoa – and Suoi Cun-type mafic – ultramafic, while Ti-Fe-(V) (mainly) ore type and Cu-Ni-(PGE) are characterized for Nui Chua-type ultramafic intrusion. Radiometric age determined for Ta Khoa ultramafic magmas is 257–270 Ma, for Suoi Cun is 260 Ma and for Nui Chua mafic magmas is 251 Ma; the ages are also applied for the related ore formation, implying that the mineralization of Cu-Ni-(PGE) and Ti-Fe-(V) in geological structures in northern Vietnam was associated with Permian – Triassic tectono-magmatic period. Besides, associated with Cu-Ni-(PGE) ore type is highly potential Ni-Co-As hydrothermal mineralization (discovered in inner contact zones in Ban Phuc block within the Song Da structure). Au-sulfur-type ore complex is widely developed in various structures in northern Vietnam; Representatives of Sn-sulfur-type ore complex are located to the southern margin of Song Hien rift and Lo Gam belt.

Major and trace elements and whole rock Sr–Nd isotope data of Late Permian silicic plutonic and volcanic rocks from the Phan Si Pan–Tu Le region in NW Vietnam were studied in order to establish their petrogenetic relationship with the magmatic rocks of the Song Da zone (NW Vietnam) and the alkaline silicic rocks of the Panxi area of the Emeishan large igneous province (ELIP) in SW China. The granites and rhyolites have geochemical characteristics of anorogenic granites (e.g. high Fe# and high Ga/Al) and are further subdivided based on mineralogy. The Phu Sa Phin and Muong Hum granites contain sodic to sodic–calcic amphiboles and sodic pyroxene, while the Phan Si Pan granite does not. The Phu Sa Phin and Muong Hum granites occasionally show peralkaline to metaluminous compositions, while the Phan Si Pan granites and the Tu Le rhyolites have metaluminous to peraluminous compositions. The chondrite-normalized REE patterns and the primitive mantle-normalized spidergrams (enrichment in high field strength elements) are similar to those of the Song Da silicic rocks. The eNd(t) values range from weakly negative to moderately positive values (−2.2 to +2.2), suggesting the silicic rocks may be assimilated by basement rocks during magma emplacement. Permian magmatic rocks in the Phan Si Pan–Tu Le region are petrologically, geochemically and geochronologically comparable to those of the inner zone of ELIP.

Reconstruction of paleo-geodynamic framework of Vietnam in the relation to major tectonic events in southeast Asia reveals that Paleozoic structures in Northern Vietnam (from northeastern Song Ma suture zone northward) were developed in the southern and southeastern margins of the Yangtze Block. Northern Vietnam is divided into two major folding systems, based on their positions relative to the Song Hong fault zone.

The Song Hien Basin in northeast Vietnam is linear- shaped, running in the northwest – southeast direction from Vietnam-China border to the easternmost of Lang Son province; with a total length about 200 km the structure divides the Ha Lang belt to the northeast and Phu Ngu belt in the south and southwest. Permian – Triassic magmatism comprises pluton-volcanic felsic and mafic bimodal magmatic associations, including basalt, gabbrodolerite – dolerite (and lherzolite-gabbronorite); rhyodacite – rhyolite and granite. These magmatic associations are spatially, temporally and genetically related. Detailed mineralogical, geochemical and chemically mineralized studies have been conducted intensively on the Song Hien magmatism; among these, the mafic and ultramafic magmas have been described separately while gabbrodolerites were grouped to pluton-volcanic basaltoidic associations. Formation ages of lhrzolite and gabbro-dolerite are 260–262 Ma, while rhyolite – 246 Ma. Geochemical and isotopic data show genetic relationship between basalts and gabbro-dolerite and rhyolite and porphyric granite.

Lo Gam structure (including Phu Ngu) in northeast Vietnam comprises Permian – Triassic gabbro-peridotite, monzogabbro, high-Al granite and syenite intrusive blocks. The studies have also revealed that gabbro – syenite magmas in folded structures around southeastern margin of the Song Chay anticlinoria form three association types distinguished by their co-existing mineral assemblages, mineralogical compositions and geochemical indexes (titanium content and alkalinity): layered peridotite- gabbro (Nui Chua complex), biotite granite (Phia Bioc complex) and compositionally heterogeneous gabbro-syenite. The uniformity of their geochemical and isotopic compositions indicates, on the one hand, generic relationship of the gabbro and syenite, and geochemically common source origin of the magmas, on the other. Being enriched in large ionic lithophile elements (LILE), rare earth elements (REE) and strongly depleted in Nb, Ta and Zr the gabbroid and syenite magmas reflect typical geochemistry of an above-subduction-zone affiliation. This is the basic feature of Permian – Triassic pluton – volcanic and plutonic magmatic associations in various geological structures in northeastern Vietnam. The formation ages of lherzolite and monzogabbro (Nui Chua complex), gabbro, syenite and biotite granite (Cho Don area) are 251–246 Ma (U-Pb, zircon, SHRIMP, Ar-Ar).

Paleogene potassic and ultra-potassic alkaline volcano-plutonic magmas in the northwestern Song Da structure and in the boundary between this structure and the Phan Si Pan uplift are compositionally diversified, ranging from alkaline mafic (lamproite, absarokite, minette) to alkaline felsic (trachyte and syenite). Geological, mineralogical, geochemical and isotpe characteristics of Ol-Cpx, Cpx-Phl lamproites, absarokite, minette and trachyte and syenite are presented. Lamproite in the northwest Vietnam are compared with low-Ti Mediterranean-type lamproite. Study on the inclusions in clinopyroxene from lamproite showed formation of the potassic and ultra-potassic magmas in the Song Da rift zone is a result of fractional crystallization of melts whose compositions were equivalent to lamproitic magmas, which were subsequently evolved by magma differentiation would lead to form diversified magmas. Mineralogical and geochemical studies of trachyte and syenite showed their genetic relationship. The formation ages of lamproite, trachyte and syenite (42–30 Ma; Ar-Ar and Rb-Sr methods) suggest they are late Paleogene intraplate extension activities in the northwest Vietnam.

The Mesozoic Chuya dike complex was recognized by R.V. Obolenskaya based on the similar mineral composition of dikes and their age characteristics. Lamprophyres occur along the large Terekta–Tolbonur and Kurai–Kobda shear zones. The Chuya complex was studied by the example of two areas, South Chuya and Yustyd, with different levels of erosional truncation. The dikes of the first area are localized in the South Chuya Ridge, where they cut Cambrian–Ordovician metamorphic rocks, and the dikes of the Yustyd area occur in the Devonian terrigenous blackshale deposits of the Yustyd trough. The dikes of these areas differ in structures, textures, the degree of carbonatization, and mineral composition. The performed studies of rocks and minerals confirmed that the dikes of both areas belong to the same complex. They helped to establish the regularities of the lithologic composition of the entire complex and its local areas and to substantiate the recognition of areas not only from their geologic position but also by the composition, structures, and textures of rocks and their mineral composition. Geochronological data show two stages of the complex formation: 236–234 and 250–242 Ma. The results of studies also demonstrate that the lamprophyres and coeval syenites of the Tarkhata massif are fractionates of the same parental melt and can be united into a hypabyssal-plutonic complex. Comparison with other Permo-Triassic lamprophyre complexes showed that the wide variations of the composition of the Chuya rocks and its trend as well as the geochemical anomalies are specific features of complexes of high-K lamprophyres.

Based on study of fluid and melt inclusions in minerals from igneous rocks and associated ore-metasomatic objects, we consider the formation conditions of oxidized fluids produced at the final stages of differentiation of alkali-basic, alkaline, lamproitic, and some granitoid melts. These fluids are characterized by wide variations in composition, concentrations, and physicochemical parameters (P, T, Eh, pH, etc.) and are of sulfate-chloride, sulfate-carbonate, sulfate-fluoride, fluoride-sulfate, essentially sulfate, and other types. The specific composition of these magmatogene fluids showing a high extractive power favors the effective removal of ore-forming elements (Fe, Mn, Co, N, Ag, Cu, Pb, Zn, Mo, W, Bi, U, REE, etc.) from melt and their trapping from the host rocks. The set of these elements is determined by P-T-X-parameters, conditions of fluid separation from melts, composition of fluid-generating magmas, and geochemical composition and metal-bearing capacity of rocks through which the fluids migrate. These factors significantly determine the metallogeny of alkaline, alkali-basic, and some granitoid complexes and associated mineralization.

Geological, isotopic, and geochemical data permitted distinguishing the Mesoproterozoic (1.6–1.05 Ga), Early Neoproterozoic (1.05–0.8 Ga), and Late Neoproterozoic (0.8–0.6 Ga) stages of magmatism and crustal evolution in the Yenisei Ridge. Each of them contributed to the regional Au metallogeny. In the Early Mesoproterozoic, crustal destruction and stretching in the southwestern Siberian craton (Yenisei Ridge) led to the initiation of a pericratonic trough, the formation of rift mafic associations (Rybnaya–Panimba volcanic belt), and the accumulation of fine-grained terrigenous sediments (Sukhoi Pit Group). Black carbonaceous shales and the picrite basalt–basalt association were enriched in Au. In the early Neoproterozoic, the terrigenous strata of the Sukhoi Pit Group were deformed, metamorphosed, and granitized as a result of the Grenville orogeny. Granite-gneiss domes formed in the earlier, syncollisional, period (1.05–0.95 Ga) of this stage, and K–Na granitoid plutons formed in the late collisional one (0.88–0.86 Ga). Premineral metasomatites formed in the zone where these plutons influenced enclosing black shale–terrigenous strata. They host Au deposits, which formed later. The formation of quartz-reef zones correlates with that of thrust nappes (0.85–0.82 Ga). The latter is genetically related to the final stage of the evolution of a collisional orogen. In the Late Neoproterozoic, rift and intraplate magmatism was most intense and frequent (780, 750, 700, 670–650 Ma) in the Tatarka–Ishimba fault system. Manifestations of Mesoproterozoic volcanism and all the Au deposits of the Central metallogenic belt in the Yenisei Ridge are concentrated here. The three periods of gold–arsenopyrite–quartz, gold–sulfide, and Au–Sb mineralization correlate well with the initiation and evolution of rift structures and the manifestations of intraplate magmatism at 800–770, 720–700, and 670–650 Ma. The tectonomagmatic processes which took place in these periods might have been crucial in Au ore accumulation.

Gold mineralization at copper-skarn deposits (Tardanskoe, Murzinskoe, Sinyukhinskoe, Choiskoe) in the Altai–Sayan folded area is related to different hydrothermal-metasomatic formations. It was produced at 400–150 ºC in several stages spanning 5–6 Myr, which determined the diversity of its mineral assemblages. Gold mineralization associated with magnetite bodies is spatially correlated with magnesian and calcareous skarns, whereas gold mineralization in crushing zones and along fault sutures in moderate- and low-temperature hydrothermal-metasomatic rocks (propylites, beresites, serpentinites, and argillizites) is of postskarn formation. Different stages were manifested with different intensities at gold deposits. For example, the Sinyukhinskoe deposit abounds in early high-temperature mineral assemblages; the Choiskoe deposit, in low-temperature ones; and the Tardanskoe and Murzinskoe deposits are rich in both early and late gold minerals. Formation of commercial gold mineralization at different copper-skarn deposits is due to the combination of gold mineralization produced at different stages as a result of formation of intricate igneous complexes (Tannu-Ola, Ust’-Belaya, and Yugala) composed of differentiated rocks from gabbros to granites.