Аннотация.Железистые минеральные воды (курорт «Марциальные воды», Карелия) по изотопному составу гелия ( 3 He/ 4 He) и неон/гелиевому отношению ( 20 Ne/ 4 He) идентифицируются как смесь подземных вод различного возраста.Тритий/гелий-3 возраст молодой компоненты составлял около 34 лет

The paper presents newly acquired data on the budget and mobility of isotopes of noble gases in samples of amphibole, a mineral commonly characterized by relatively high He concentrations compared to other rock-forming minerals of Earth’s crust. In the amphibole samples from alkaline granites of the Ponoy Massif, Kola Peninsula, 3He, 4Не, and 40Ar* isotopes were mostly radiogenic, generated by radioactive decay and nuclear reactions. Retention ability of two helium isotopes was found to be different: since the time of metamorphic event approximately 38% 3Не and only approximately 16% 4Не have been preserved. A small He fraction (≈3% of its total concentration) and a larger part of radiogenic 40Ar* (≈35%) are hosted in fluid inclusions. Relatively high 3Не/4He ratios (up to ≈1 × 10–6) in the amphibole were caused by the high Li concentrations and better preservation of 3Не. The 3He/4He ratios in helium extracted from the samples by melting and crushing are indistinguishable, while the 4He/40Ar* ratios in the fluid inclusions (opened by sample crushing) (~0.6) are notably lower than those in the bulk samples (melting) (5) and those calculated from the U, Th, and K concentrations (15). Two He release peaks were observed on the curves of rapid (12–40°C min–1) liner heating of the samples. At a lower heating rate (~5°C min–1), the high-temperature peak disappeared. Further investigation of this peculiarity of He migration has shown that (1) it is also typical of some other amphibole samples (not only those from Ponoy granites); (2) He amount in the “disappearing” peak varies from sample to sample and also depends on the heating rate and grain size (powdered samples with an average grain size of ≤50 µm did not yield the second peak, regardless of the heating rate); (3) the temperature of He release from powdered samples is approximately 50°C lower than that for mineral grains; and (4) preliminary long-term heating of the sample to 400°C (a temperature at which He starts to diffuse from the amphibole structure) results in a significant decrease in the low-temperature peak and a shift of the “disappearing” peak toward lower temperatures. The probable reasons for this phenomenon are discussed.

The first evidence for a specific role of amphiboles in He isotope balance of crustal rocks was presented in early contributions by Gerling et al. (1971, 1976). Since then it was shown that 4He and 3He concentrations in amphiboles generally exceed those in the host rock samples. Recently amphibole was considered as an important carrier of noble gases and other volatiles components in the course of their subduction into the mantle. This paper presents new data on the balance and mobility of noble gas isotopes and major gas constituents in amphibole separates in order to understand sources and evolution of volatile components of 2666Ma old alkaline granites from Ponoy massif (Kola Peninsula), which underwent metamorphism 1802Ma ago.In the amphiboles 3He, 4He and 40Ar* were dominantly produced in situ due to radioactive decay of the parent isotopes and associated nuclear reactions. A small fraction of He (≈3% of the total) is liberated by crushing and shows 3He/4He ratio indistinguishable from that found by total extraction. The fraction of trapped 40Ar* amounts to ≈40%; both these fractions presumably occupy fluid inclusions and show rather low 4He/40Ar*≈0.1, a factor of ≈ 150 below the production ratio (calculated assuming no loss/gain of the species has happened since the time of metamorphism).3He has been better preserved in amphiboles compared with 4He: the retention parameter (measured amount of He/totally produced amount) for 3He (≈0.4) exceeds that for 4He (≈0.15).He extraction by fast and slow linear heating of amphiboles resulted in different release patterns. The fast heating (within 12 to 40°Cmin−1) revealed a superposition of two peaks. When heating with slower heating rate (below 8°Cmin−1) was applied, the high-temperature peak disappeared (the “disappearing site”). Extractions of He atoms from grain and powder samples at different heating rates have shown that: (1) the “disappearing site” is revealed by the fast heating analyses of different amphibole samples but not only those from the Ponoy massif; (2) amount of He liberated from the “disappearing site” is variable and generally much less than the total amount of He in the sample; (3) analysis of the powder produced in the crushing experiments never reveals the “disappearing site”; the temperature of He release from the powder is lower than that from the mm grain size sample by ≈50°C. Possible explanations of the nature of the “disappearing site” are discussed. However, independently on nature of this effect, repeated gas extractions by heating at different rates would give additional information about structure and its transformation during heating of amphiboles.The simplest explanation of the observed abundances of noble gas isotopes in the amphibole separates from Ponoy granites suggests local production, redistribution and partial loss of noble gases during evolution of the massif.

Исследованы условия выращивания кристаллов LiNbO3 Zn в интервале концентраций примеси 4.0 8.91 мол. % ZnO. Показано, что в области концентраций 4 6.8 мол. % ZnO в расплаве возможно выращивание композиционно и оптически однородных кристаллов LiNbO3 Zn При концентрации ZnO > 6.8 мол. % вырастают дефектные кристаллы, содержащие две различные фазы. Уточнены пороговые концентрации примеси, соответствующие существенному изменению условий кристаллизации кристаллов LiNbO3 Zn .

The measurement of 3H, 3He, 4He, and 20Ne concentrations in waters at the Tsentralny pumping station (southern Khibiny massif, Kola Peninsula) showed that they are a mixture of young (>90%) and old (<10%) waters. The excess noble gas component from the young water is caused by the dissolution of air bubbles trapped during recharge in the unsaturated zone. The 3H-3He(3H) age of the young water is 21 ± 1.5 yr. The U-Th-4He age of the old water is about 50 ka. The high concentrations of helium and some toxic elements (e.g., aluminum) in this old water are caused by dissolution of the alkaline rocks of the Khibiny massif as a result of water-rock interaction.

Thermal analysis of helium release from ilmenite of alkaline granites (Ponoy Massif, Kola Peninsula) and extraction of gases by crushing, melting and vacuum stepwise heating of sample revealed that this mineral contains noble gases in several different residence sites (rs). Radiogenic 40Ar* and He are released within the temperature range of 400–600°C. However, in spite of the similar extraction temperatures, these gases occupy different rs: trapped excess 40Ar* is localized in relatively large inclusions (> 10 μm) and was almost completely released during crushing (more than 80%, first rs), whereas He is localized in “healed” α-tracks and was released during sample heating (second rs). The third rs is almost completely occupied by radiogenic He released at temperature around 1100°C; this temperature fraction has 4He/40Ar* = 830, whereas this ratio in whole sample is 10. Helium with the highest 3He/4He = 1.1 × 10−6, indicating a contribution of mantle helium, is released from the fourth rs. Observed distribution of helium and argon isotopes in ilmenite is consistent with geological data on the evolution of the Ponoy Massif. Quartz-feldspathic vein, from which ilmenite was collected, was formed by crystallization of residual alkali granitic melts; the melts contained mantle He, which finally was incorporated in primary inclusions (fourth rs). After formation, the massif rocks accumulated radiogenic 40Ar*, but lost more mobile radiogenic He. During Paleoproterozoic metamorphism of the Ponoy Massif, radiogenic 40Ar* was released from K-bearing minerals of granites and impregnated “potassium-poor” ilmenite (first rs). Then, trapped 40Ar* was preserved in mineral inclusions, while helium produced “in situ” during radioactive decay of U and Th mainly migrated from the mineral. At present, ilmenite is characterized by significant excess 40Ar*, and, simultaneously, by 4He deficit (second and third rs). Neither K-Ar, nor U-Th-He isotope systems of the mineral can be used for dating.

Previously published data were analyzed on the isotopic systematics of noble gases extracted from samples using various methods. By the example of four minerals from the rocks of the Kola Peninsula, it was shown that a comparison of the results provides the most comprehensive and reliable information on the qualitative and quantitative composition of gases and allows discrimination between fluid microinclusions of different origin (primary and secondary).

The liquidus surface temperatures, eutectic temperatures and compositions, phase crystallization fields, and phase separation regions are determined for the albite–apatite, anorthite–apatite, orthoclase–apatite, diopside–apatite, albite–diopside–apatite, anorthite–diopside–apatite, and orthoclase–diopside–apatite systems. The influence of the composition of the silicate melt on the solubility of apatite is described in a mathematical form. A program of calculating the limiting solubility of apatite in the silicate melt is developed.

LiNbO3 crystals doped with Gd, Zn, Cu, and Er to various levels were grown by the Czochralski technique. The structural parameters, Curie temperature, and density of the LiNbO3 crystals were determined as a function of composition. With increasing Gd content, thea parameter of the hexagonal cell increases, c remains constant within the experimental error, density increases, and Tc gradually decreases. The defect structure and properties of LiNbO3 doped with Gd, Zn, Cu, Er, Mg, and Ta are contrasted with those of nominally undoped LiNbO3 crystals differing in Li/Nb ratio. The results suggest that the variation of the Curie temperature with composition is determined primarily by the position that the dopant cations occupy in the structure of lithium niobate.

Phase equilibria in the system Formed by rubidium and nickel fluorides were studied by differential-thermal and X-ray phase analyses.

The phase diagram of the system formed by cobalt and rubidium fluorides was studied by differential-thermal, visual-polythermal, and X-ray phase analyses.

Visual polythermal and differential thermal analyses were used to study phase diagrams for mixtures of sodium and nickel fluorides or potassium and nickel fluorides.