The Dzhida ore field includes Pervomaika (Mo), Inkur (W) and Kholtoson (W) deposits. This article presents stable and radiogenic isotopic data (O, C, D, S, Sr and Nd) in an attempt to better understand the petrogenetic processes and the problem concerning the sources of ore-forming fluids. Granites from the Pervomaika deposit, which includes Mo-ores, as well as the syenite dikes that precede W-mineralization, have low δ¹⁸O values (about 5‰ and 4‰ respectively), and low initial ratios ⁸⁷Sr/⁸⁶Sr (0.704–0.705). The εNd (T) values (+0.9–−1.1) in granites and syenites are close to the evolution trend of the mantle-derived source. It was determined that a mantle-derived source was involved in ore-forming processes. It was also confirmed that δ³⁴S values in sulfide minerals (molybdenite, pyrite, sphalerite, galena, and chalcopyrite) were close to the meteoric standard (from −2‰ to +2‰). The δ¹³C and δ¹⁸O values in carbonate minerals (rhodochrosite and ankerite) of the Kholtoson deposit are located within the primary igneous carbonatite (PIC)-square, as a possible juvenile source of CO₂. This was also confirmed by the δ¹⁸O and δD values in muscovite from greisens (4.2‰–6.5‰ δ¹⁸O, –78.8‰ … –84.0‰ δD). The δ¹⁸O values calculated in a fluid equilibrated with hydrothermal minerals indicated a meteoric origin.

Ингурский массив щелочных гранитов и связанное с ним Zr-Nb проявление входят в состав Монголо-Забайкальской щелочно-гранитоидной провинции. Массив сложен арфведсонитовыми, биотитовыми и аляскитовыми гранитами. Для них характерно высокое содержание тяжелых РЗЭ, что определяет низкую величину La/Yb_n (2–7), и отрицательная европиевая аномалия (Eu/Eu*≈0.17). Они обеднены Ba, Sr и обогащены Nb, Ta, Zr, Hf, Y. По своим геохимическим характеристикам породы массива относятся к А-типу гранитов. Редкометалльная минерализация гранитов Ингурского массива представлена в основном цирконом, бастнезитом, монацитом, ксенотимом. U-Pb возраст (SHRIMP II), определенный по циркону из арфведсонитовых гранитов (272 млн лет), указывает на их раннепермский возраст.

The paper presents the mineralogical and geochemical characteristics of two groups of hydrothermal rocks and their relation with subalkaline granites of the Ermakovskoe deposit. The first group includes fluorite-phenakite-bertrandite ore bodies, occurring outside the granite massif. The second group is presented by silicification bodies with sulfates, phosphates, kaolinite, muscovite and hematite. It bears REE (rare earth elements) mineralization (monazite, florencite, xenotime) and occurs within the massif. Our research included isotopic analyses of Sr, Nd and O, studies of trace, including rare-earth element compositions and age determination (U-Pb) of apatite from F-Be ores. Geochemical and isotopic studies are not according with relation between F-Be ores and granites. This is proven by the absence of Be-mineralization in granites and schlieren pegmatites, and a sharp difference in composition of their fluid phases. A reductive fluid specification forming F-Be ores (containing CH4, H2, N2, CO2 and H2S), contrasts sharply with fluid specification of granites. The granites are characterized by high oxygen fugacity, due to ferrous iron, sulfates and phosphates. Besides isotopic composition of oxygen in quartz (7.4 and 5.1‰ δ18О V-SMOW respectively), initial Sr ratios (0.7056-0.7065 and 0.707-0.709 respectively) and REE compositions are different.