Ore Field Research Articles

Scientific achievements of USMU employees in the field of searches and exploration of deposits of piezo-optical and vein quartz

The study of deposits of piezo-optical and vein quartz in the Middle and Southern Urals by employees of the Ural State Mining University (Sverdlovsk Mining Institute) took place in two stages. The period of active introduction of scientific achievements of the Sverdlovsk school of quartzists under the guidance of Professor G. N. Vertushkov lasted more than 30 years – from 1950 to 1980. As a result, a method of field observations and laboratory studies of vein quartz was developed, namely, quartzometric survey, the effectiveness of which was proved by its use for 50 years. The second period of scientific study of quartz deposits proceeded from 1992 to 2020. The creative scientific team of the Department of Geology, consisting of Doctors of Geological and Mineralogical Sciences V. N. Sazonov, V. N. Ogorodnikov, Yu. A. Polenov and Candidate of Geological and Mineralogical Sciences A. N. Savicheva continued a detailed study of gold and quartz deposits. The subject of the closest attention of the authors was the connection between the processes of ore formation and changing geodynamic conditions. It has been established that many ore fields of the Ural deposits are polychronous and polygenic.

Multi‐Isotope Based Identification and Quantification of Oxygen Consuming Processes in Uranium Hosting Aquifers With CO2 + O2 In Situ Leaching

AbstractAlthough neutral in situ leaching through CO2 + O2 is employed to extract uranium (U) in sandstone by in situ leaching (ISL), mechanisms of U mobilization and O2 consumption remained unclear. To address this gap, 18 groundwater samples were taken from the Qianjiadian sandstone U ore field, including seven samples from production wells in mining area M1 (mining for 5 years), six samples from production wells in mining area M2 (mining for 4 years), and five samples from monitoring wells (GC), to quantify U‐mobilizing processes in the mining aquifer by employing hydrogeochemical compositions and multi‐isotopes. The introduction of O2 and CO2 efficiently stimulated U mobilization in the mining aquifer. The injected CO2 critically promoted the dissolution of carbonate minerals, which enhanced the formation of uranyl carbonate (predominantly CaUO2(CO3)22− and Ca2UO2(CO3)3(aq)) and thus facilitated U mobility. Generally, δ34SSO4 and δ18OSO4 in M2 and M1 were significantly lower than those in GC (p < 0.01). A Bayesian isotope mixing model of δ34SSO4 and δ18OSO4 showed that the contribution of pyrite oxidation to SO42− concentration increased from 1.7% in GC to 13.6% in M2 and to 15.0% in M1. During ISL, pyrite, ammonium, and dissolved organic carbon were major compounds competing with U(IV) for introduced O2 in the ore‐bearing aquifer. Most of the consumed O2 was used for pyrite oxidation (56.2%) and U(IV) oxidation (39.3%), following the thermodynamic sequence of those redox reactions. The current results highlighted the significance of increasing O2 utilization efficiency in improving the performance of ISL operations.

Tectonophysical Forecasting Criteria of Vein Bodies Thicknesses in Deep Horizons of the Nadvigovaya Zone, Badran Ore Field, Republic of Sakha (Yakutia)

A new technology of stress inversions is proposed on the basis of data of mute fracturing with measured amplitudes of dilative opening of fractures (tension shear), which are registered by mineralization (vein bodies). The involvement of a basic law of geomechanics of supercritical deformation, which determines the interrelation between amplitudes of shear deformations and deformations of transverse extension (dilatancy), allows us to link the amplitudes of opening of shear fractures with the level of Coulomb stresses. This approach can be used for a conjugated fracture system and fault zones with a system of similarly oriented fractures. Our algorithm and technology of stress calculation consist of consecutive analysis of a geometrical form and characteristic lineaments of density zone of fracture poles on the stereospheres and stress conditions of these fractures on Mohr’s diagram. The algorithm allows the calculation of the parameters of stress tensor both on the basis of graphical analysis on the stereonets and Mohr’s diagram and using a group of formulas. The algorithm is applied for the Nadvigovaya zone of the Badran deposit. The stress values are calculated for a fault area with measured fracturing, and a forecast for promising areas is given for a deeper fault part in areas with possible most intense dilatancy of fracture flow.

The use of chlorine-containing agents in the processing of spent blocks of uranium deposits

The work is aimed at diversifying existing mines for the extraction and processing of natural uranium through additional processing of spent blocks of uranium deposits with chemical solutions using the method of in-situ well leaching (ISL) in order to extract associated useful components. A feature of this technology is the use of the existing production infrastructure for the extraction of associated useful components in existing uranium mines, without significant capital investments in production infrastructure and mining operations. The technology of underground borehole leaching has been reliably developed in uranium deposits for decades. The fundamental similarity of the technology for the extraction of uranium and a number of associated useful components (APC) - by the ISR method, allows the use of spent ore fields of uranium deposits for the extraction of PPC. The use of ready-made technological infrastructure (wells, pipeline network, pumping equipment, control units, etc.) allows, due to savings on infrastructure costs, to obtain profitability when mining ore-bearing blocks with a content of recoverable components from ≤ 1 g/t, up to 0.1 g/t. Taking into account the indirect savings of significant costs for the reclamation of spent blocks, it will be profitable to mine blocks with a content of recoverable components up to 0.01 g/t. In view of the foregoing, this technology has a good prospect for implementation in production.

SHRIMP U-Pb zircon geochronology of the Dhzida intrusive rocks in the Tavt ore field, northern Mongolia

The Tavt ore field is located in the northern part of Mongolia. The ore field containing the Tavt gold deposit, which covers 90 square km, is in the Dzhida terrane at the junction of two regional faults that trend NW and NE, respectively. This terrane, which spans the border between Mongolia and Russia is overlapped and stitched with Orkhon-Selenge trough assemblages. The geology of the deposit consists of the Early Paleozoic Dzhida intrusive complex, the Middle Paleozoic Tes intrusive complex, the Late Paleozoic Selenge intrusive complex, the Early Mesozoic Orkhon complex, and the Ediacaran-Early Cambrian metavolcanic Badariingol formation, Early Cambrian silicic-terrigenous-carbonate Burgelt formation. Zircons SHRIMP U–Pb ages from the Tavt intrusive rocks are slightly different: 505.3+3.8 Ma for plagiogranites, 512.7+4.1 to 514.4+3.0 Ma for granodiorites, 506+3.4 Ma for quartzmonzodiorites, 510.1+2.9 Ma for monzodiorites and 509.8+3.7 Ma for subalkaline diorites, respectively. It indicates that the Dzhida intrusions have formed at the island arc environment since the middle Cambrian ages.

Study on Epithermal Gold Mineralization System at Shwebontha Prospect, Monywa Copper-Gold Ore Field, Central Myanmar

The Shwebontha prospect area is situated in the Central Volcanic Belt, central Myanmar, where the well-known Sagaing Fault serves as its eastern boundary. This study aims to document key the mineralogy, host rock geochemistry and ore mineralizing fluids. The mineralization, hosted by Upper Oligocene to Middle Miocene rhyolites, displays a strong lithological control. Mineralization is characterized by gold-bearing silicified massive ore and chalcedonic quartz veins in which sulfides are clustered and disseminated not only in quartz gangue but also in rhyolite host rocks. The significant ore minerals in the mineralized veins include pyrite, sphalerite, galena, chalcopyrite, and gold. Common hydrothermal alterations such as silicic, argillic and propylitic alteration types are recognized. According to the fluid inclusion data and interpretation, ore mineralizing fluids in the research area are characterized by formation temperatures of 260-280 °C and salinity of 0.35-2.41 % wt. NaCl eq. respectively. Mixing of hydrothermal fluids was generally considered to be an effective mechanism for ore transport and deposition.

In situ trace element compositions and U[sbnd]Pb ages of cassiterite from tin-polymetallic deposits in the Dachang district, Guangxi, China: Implications for ore genesis and exploration

The Dachang tin-polymetallic district in southwest China is one of the largest tin ore fields in the world containing approximately 1.5 Mt. Sn, 6.8 Mt. Zn, 1.8 Mt. Pb, 1.4 Mt. Sb, 0.4 Mt. Cu and other critical metals. Both cassiterite-sulfide and ZnCu skarn mineralization occur as stratiforms, veins, and stockworks and are hosted in the Mid-Upper Devonian carbonate-rich sediments adjacent to the underlying Late Cretaceous Longxianggai granite pluton and/or the granite/diorite porphyry dikes. The Tongkeng and Huile deposits are typical stratiform- and vein-type tin-polymetallic deposits in the district. Previous studies suggest a genetic link between these tin-polymetallic deposits and the prolonged Longxianggai granite which was dated to have emplaced for multiple stages within ca. 91–97 Ma. However, existing constraints on the timing of tin mineralization display a board range at 90–96 Ma, whereas the accuracy and precision of these ages are less satisfactory. These ages are broadly overlapping with both the prolonged Longxianggai granite and the porphyry dikes (91 Ma), thus gives rise to question on their genetic association, which is a question of importance for ore exploration in the district.In this study, a large number of measurements of laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) trace elements and UPb dating on cassiterites from the Tongkeng and Huile deposits was performed and their mineralization ages with hitherto the best accuracy and precision were obtained. LA-ICP-MS trace element analyses show that cassiterites from the Tongkeng and Huile deposits contain concentrations of Fe, W, Nb, and Ta characteristic of granitic-related skarn-type tin mineralization. UPb dating on cassiterites from 391 spots analyses yielded well-constrained ages of 91.13 ± 0.61 Ma to 89.46 ± 0.47 Ma for the Tongkeng deposit and 89.0 ± 1.3 Ma for the Huile deposit. These ages are apparently younger than the dominated equigranular phase of the Longxianggai pluton, but they agree well with the emplacement ages of the porphyritic granite represented either by the latest phase of the Longxianggai granite or the granite porphyry dikes (ca. 91 Ma). This suggests that the tin-polymetallic deposits in the Dachang district were most likely genetically associated with later, higher evolved granitic phases in the district. In this regard, the dike-hosting fault systems were most likely served as fluid conduits and their surrounding host rocks are favorable targets for ore exploration in the Dachang district.

Secondary minerals of Fe, Pb, Cu in sulfide-containing tailings: sequence of formation, electrochemical reactions and physico-chemical model (Talmovskie Sands, Salaire, Russia)

The results of studies of the composition and form of secondary minerals Fe, Pb, Cu, formed under contrasting physico-chemical conditions of the accumulated tailings from the enrichment of barite-polymetallic ores of the Salair ore field, are presented. The complex mineral composition of ores (pyrite, chalcopyrite, sphalerite, galena, fahlore) and long-term processes of chemical weathering of the substance contributed to the formation of monomineral and zonal secondary rims and fillings of the intergranular space, which were identified using modern research methods. Plumbojarosite, anglesite, cerussite, and iron hydroxides predominate among them; pyromorphite, ginsdalite, and covellite occur less frequently. The method of thermodynamic modeling was used to solve the inverse problem - the restoration of the composition of solutions that led to a change in the associations of secondary minerals. The nature of the ongoing processes can be characterized not only by chemical interactions, but also by electrochemical reactions in the systems under consideration, where various mineral components act as galvanic pairs, which, in combination with the physico-chemical parameters of the medium (pH, Eh, ionic composition of solutions ), leads to stepwise or incomplete oxidation of the original minerals with subsequent selective deposition of secondary compounds.

Improving the geometrization reliability of qualitative indicators of phosphate ores during their open mining on the example of the Kovdorskoye apatite and staffelite ore field

Background. In this paper, available methods for determining the geometry and density of exploration networks used in operational planning are discussed, along with approaches to determining the permissible error limits in the assessment of geological indicators. The Kovdorskoye apatite and staffelite ore field was selected as a research object.Aim. To determine the rational parameters of an in-mine sampling network for use in operational planning of phosphate ore mining.Materials and methods. The research was carried out as part of a project on the development of a methodology for operational in-mine sampling of apatite and staffelite ores. Quantitative data were processed and analyzed using the methods of mathematical statistics and cartography.Results. The conducted geometric autocorrelation and assessment of the anisotropy of variability in the content of components, which determine the quality of mineral raw materials, allowed the author to establish the rational parameters of an operational in-mine sampling network during the extraction of phosphate raw materials from the Kovdorskoye apatite and staffelite ore field.Conclusion. The absence of a pronounced anisotropy in the content of P2O5 and CO2 in apatite and staffelite ores was established, which implies the feasibility of using a uniform in-mine sampling network. The parameters of such a network were determined, which confirm the need to sample the rock cuttings in each borehole.

OXYGEN ISOTOPE SYSTEM OF LEUCOGRANITES OF THE OMSUKCHAN TROUGH (NE RUSSIA): CONDITIONS AND MECHANISMS OF WATER-ROCK INTERACTION

The oxygen isotopic composition of minerals (Qtz, Zrn, Kfs) and bulk samples of Late Cretaceous porphyritic leucogranites of the Omsukchan trough, which are associated with the formation of tin and Sn-polymetallic mineralization, was studied. The δ18O values of bulk samples of leucogranites decrease from +9.7‰ (outside the Dukat ore field) to 10.6‰ (within the ore field), and the light isotope characteristics are mainly an attribute of feldspars and correspond to isotope exchange with meteoric fluid (δ18О = –15‰), over a wide range of T at limited fluid-to-rock ratios (W/R from 0.9–1.6 to 0.3–0.1). Unlike feldspars, the δ18O values of quartz and zircon are partially changed, in the former, probably, by the diffusion mechanism, and in the later, by the dissolution-precipitation one.

Mineralization age and genesis of the makeng-style iron deposits in the Paleo-Pacific tectonic domain of South China: In situ LA-ICPMS garnet U-Pb chronological and geochemical constraints

To reveal the genesis of Makeng-style iron polymetallic deposits from SE China in the paleo-Pacific tectonic domain, a new analytical method of LA-ICPMS garnet U-Pb dating and rare Earth element analysis was conducted for the Makeng, Luoyang, Dapai and Pantian deposits. The U-Pb dating results of nine garnet skarn samples from these deposits suggested that the Makeng-style iron polymetallic deposits mainly formed during 137–130 Ma, which is consistent with the zircon U-Pb and molybdenite Re-Os ages. This study provides more direct evidence of the mineralization age and the relationship between mineralization and granite, compared with previous studies on the zircon U-Pb dating for granites in the ore fields. Rare Earth element (REE) analysis results and REE patterns of four representative garnet samples from the Makeng, Luoyang, Dapai and Pantian deposits show that they are similar to typical skarn deposits, but obvious differences in the REE distribution types indicate that the ore-forming process may be distinct due to different mineralizing fluid for these Makeng-style deposits. Our new garnet U-Pb dating and rare Earth element analysis result not only provides new evidence for the mineralization age and genesis of the Makeng-style deposits but is also of great significance to promote the application of U-Pb dating methods to research skarn type deposits.

Characteristics and Formation Conditions of Se-Bearing Metacinnabar in the Wanshan Mercury Ore Field, Eastern Guizhou

Cinnabar (α-HgS) is the most common sulfide of mercury while metacinnabar (β-HgS), a high-temperature homogeneous polymorph of the mercury sulfide, is relatively rare, and the α phase of cinnabar transforms to the β phase at 344 °C. Meanwhile, there is a complete isomorphic series between HgS and HgSe, and the occurrence of Se-bearing metacinnabar is of great significance for the exploration of selenium resources. We studied through microscopic observation, electron-probe microanalysis, X-ray diffraction and field emission scanning electronic microscopy (FESEM) the Se-bearing metacinnabar of the Wanshan mercury ore field of southeastern Yangtze Block. These analyses, combined with physicochemical phase diagrams, constrained the textural and chemical evolution during the formation process of Se-bearing metacinnabar. Se-bearing metacinnabar was found in altered carbonatite, intergrown with cinnabar, sphalerite, pyrite, realgar and quartz. The Se-bearing metacinnabar contains 77.66–84.01 wt.% Hg, 0.18–1.17 wt.% Zn with extensive isomorphic substitution of Se and S (2.79–14.77 wt.% Se, 6.15–11.82 wt.% S). The presence of impurity elements (e.g., Zn and Se) is considered to be the key factor in expanding the stable range of Se-bearing metacinnabar. The cinnabar generated by the transformation of Se-bearing metacinnabar is characterized by inclusions of Hg-bearing sphalerite and pores, which indicate that this process was carried out through a coupled dissolution–reprecipitation (CDR) reaction. The formation temperature of Se-bearing metacinnabar is higher than that of cinnabar, and according to the phase relations between sulfides and selenides, we propose that logfS2(g) of ore-forming fluids is constrained within −15.663 to −13.141, and logfSe2 < logfS2–3.994 (150 °C).

Comparative Studies on the Extraction of Lineaments and Its Variability Based on an Improved Line Segment Tracking Method—Taking the Gaosong Ore Field in the Gejiu Gejiu Tin Ore Deposit as an Example

Remote sensing technology is widely used in the application of the extraction of lineaments in geological research. However, most of the current traditional lineament extraction methods are based on edge detection technology using a digital filter to extract the mitochondrial features in the image. These previously used algorithms are generally unable to extract the mitochondrial features in the shadow area on the mountain and the area parallel to the direction of the solar incident angle. In this paper, we have improved the STA algorithm (Line Segment Tracking method). The line segmentation and connection methods were firstly proposed, and then 32 search directions were set with one pixel as the center to find the best continuity direction of the lineament. A threshold was then set in this direction to determine whether it was a line element. Finally, line elements were connected into lineaments for further lineament interpretation. The lineament data from three different directions were collected in the Gaosong ore field in the Gejiu mining area, namely at the first place the traditional Canny algorithm, then the improved line segment tracking method, and finally the field measurement. The coefficients of the three-type lineament variations were compared by calculating the lineaments’ strength and their density attributes. It shows that the lineament variability extracted based on the improved line segment tracking method is closer to the measured lineament variability. The results show that the lineaments extracted by the improved algorithm are closer to the measured data. The improved algorithm has higher precision than the traditional Canny algorithm. More realistic and comprehensive lineaments can be attained by using the improved method to extract lineaments in the mining area, which is helpful to the study of the geology of the mining area and helps to construct a more accurate structure model to serve the needs of the mine production.

LA-ICP-MS study of malachite from copper deposits in the Rosen ore field, Burgas ore district, SE Bulgaria

Archaeological findings of malachite ore pieces, and objects made of malachite or copper, raise the question of where the raw material was mined. Research in this direction is a challenge in modern applied mineralogy, especially concerning minerals from the oxidation zone of copper-bearing ores. According to recent studies in this field, a complex research method, including impurity elements, will provide a better distinction between different sources. The present paper is focused on the content of impurity elements in malachite ore samples from copper deposits in the Rosen ore field, SE Bulgaria, with mining activity in the past: Propadnala Voda, Sarneshko Kladenche, Meden Rid, Korucheshme, and Rosen. The nickel concentration obtained by LA-ICP-MS analyses is above 1000 ppm (1012.80–1505.15 ppm) in all studied samples, accompanied by the following element impurities: Zn, Co, Mg, As, Sb, Fe, Ag, Au, Sn, Se, and Te. The quantitative concentrations of Zn, Co, Mg, As, Ag, and Se vary in different ranges in the examined malachites from each locality. Based on this, it seems possible to differentiate between samples of each mineralization. These data would have to be supplemented by the analyses of more malachite ore samples from the region.

Petrogenesis of the Helong Granites in Southern Jiangxi Province, China: Constraints from Geochemistry and In Situ Analyses of Zircon U–Pb–Hf Isotopes

The Jinzhuping and Changkeng granites are related to the Helong W–Sn ore field in southern Jiangxi Province, China. Three different phases can be found in the Jinzhuping pluton, and their LA-ICP-MS zircon U–Pb ages are 155.2 ± 0.68 Ma, 154.0 ± 0.56 Ma, and 153.4 ± 0.99 Ma, respectively, indicating two types of granitic rocks. All granites in the Helong ore field have similar geochemical characteristics, they have high contents of SiO2 (73.99 wt.%–77.68 wt.%), and total alkali (7.56 wt.%–8.76 wt.%) and are weakly to strongly peraluminous. They are slightly enriched in HREE and depleted in Eu, Ba, Sr, P, and Ti. Zircon εHf(t) values of the Jinzhuping three granites are from −14.4 to −10.4, from −15.3 to −11.4, and from −18.1 to −10.5, and the Hf TDM model ages range from 1.83 to 2.06 Ga, from 1.89 to 2.14 Ga, and from 1.83 to 2.31 Ga, respectively. Whole-rock geochemistry and Hf isotope analysis indicate that the Helong granites experienced a high degree of differentiation and evolution derived by partial melting of the Late Paleoproterozoic crustal materials, and they formed in a backarc caused by low-angle subduction of the Paleopacific plate.

Discovery of New Hydrothermal Ore Fields “Korallovoe” (13°07′ N) and “Molodezhnoe” (13°09′ N) in the Middle Atlantic Ridge

During the 41th scientific cruise of the R/V “Professor Logachev” in 2019, two new ore fields were discovered within the Russian exploration area of the Mid-Atlantic Ridge. The “Korallovoye” ore field is located in the middle part of the rift valley ridge and lies on a gentle slope in the depth range of 2800–2850 m. The “Molodezhnoye” ore field is located at a distance of approximately 5 km northeast of the “Korallovoye” field and lies on a less steeper section of the slope between 3500 and 3550 m in depth. The “Korallovoye” and “Molodezhnoye” fields are confined to the outcrop of a gabbro-peridotite massif on the western side of the Mid-Atlantic Rift valley. The total number of discovered ore fields in the Russian exploration area has been increased to 14 sites.

Новые данные о петците Балейского рудного поля в Восточном Забайкалье

The relevance lies in the need to get data on the chemical composition, abundance and paragenesis of petzite, which is one of the mineral carriers of Te, Au and Ag in the gold and silver ores of the Baley ore field in Transbaikalia. During the development of deposits in the ore field, only Au and Ag were extracted, Te went to the dump. The deposits have not been fully developed. The remaining Au reserves of the Taseevskoye deposit are 105 tons, the Au resources of the Baley deposit are estimated at 35 tons. In connection with the extraction of the remaining reserves of Au–Ag ores of these deposits, where part of Te is in the form of petzite Ag3AuTe2, information about it will be important for the development of technology for its extraction along with other tellurides. The purpose of the study is to understand the chemical composition and paragenesis of petzite. The tasks are to study the composition of petzite and petzite-bearing mineral associations of the Baley ore field. The object of the study is Au–Ag ores of the Baley ore field, the subject of the study is the forms of isolation and the chemical composition of petzite. Methodology and methods – optical and electron microscopy with the identification of shapes and sizes of individuals and aggregates of petzite, determination of its chemical composition. Research results are the following: for the first time, the study of the chemical composition of petzite in the ores of the Baley ore field, its abundance and paragenesis has been carried out. It is found in association with hessite, native gold, miargyrite, tetrahedrite, tennantite, pyrite, chalcopyrite, sphalerite, altaite, coloradoite, schützite, andorite, robinsonite, quartz, adularia, carbonates, kaolinite and other minerals. The chemical composition varies within the limits (wt%): Ag 41.57–48.16; Au 18.55–26.01; Te 30.79–35.18. Petzite average chemical composition (wt%): Ag 43.91; Au 22.61; Te 33.16. This indicates the nonstoichiometric composition of its composition and an excess of Ag and Te and a deficit of Au. Petzite, as a carrier of these elements, can be one of the sources of Te in the technology of processing gold and silver ores.

МЕДНО-ПОРФИРОВАЯ МИНЕРАЛИЗАЦИЯ ТАЛЬНИКОВОГО РУДНОГО ПОЛЯ (ОХОТСКИЙ СЕГМЕНТ ОХОТСКО-ЧУКОТСКОГО ВУЛКАНОГЕННОГО ПОЯСА)

The Talnikovoye ore field where previous academic research and exploration work revealed porphyry copper mineralization is described. Our data show that mineralization is confined to the intrusions of Turonian granodiorite and quartz diorite (91 Ma, U-Pb metohod), as well as the accompanying hydrothermal-explosive breccias. Biotite-epidote-chlorite propylites are widespread within the ore field; in the southern part, phyllic alteration is superimposed on the halo of K-feldspar alteration. The ore occurs in zones of intense quartz, chlorite-epidote-quartz (with chalcopyrite and molybdenite), sulfide-potassium feldspar-quartz (with chalcopyrite and bornite), and sulfide-quartz-sericite (with chalcopyrite) stockwork veining with copper-molybdenum mineralization. They are characterized by moderate concentrations of Cu (0.1–0.3 %, reaching 1.1 %) and Mo (up to 0.1 %), low concentrations of Au (up to 0.1 g/t) and Ag (up to 2.6 g/t) and have a Cu-Mo-(Au, Ag, Pb, Zn, Sb, As) geochemical signature. Fluid inclusion data suggest the formation of mineralized veinlet quartz during the magmatic-hydrothermal transition (430–150 °С) with solutions at high (50 wt % NaCl equiv.), medium and low concentration (5–18.9 wt % NaCl equiv.) involved under the cooling-dilution scenario. Values of the main geochemical indicators, such as Cu/Mo (30–60) and Cu/Au (> 1 × 105) ratios allowed us to assign the Tal’nikovoye ore field to the porphyry copper-molybdenum type characteristic of continental-margin volcano-plutonic belts formed at the mafic island-arc basement. The geochemical parameters of porphyry granitoids indicate their formation in a setting of subduction-to-transform plate boundary transition.

FEATURES OF LOCALIZATION OF APATITE-BEARING ALBITITES OF THE KIROVOHRAD ORE DISTRICT (THE INHUL MEGABLOCK OF THE UKRAINIAN SHIELD)

Geological setting and features of localization of apatite-bearing albitites of the Novokostiantynivka ore field and the Kirovohrad ore district in tectonic structures of the Inhul Megablock of the Ukrainian Shield are considered for the first time. The typical occurrences with increased phosphorus grades are spatially related to contact of the Novoukrainka massif and the Korsun- Novomirhorod pluton: Ulianivskyi, Tymoshyvskyi, and other occurrences. Unusual sodium metasomatites with 8 % of P2O5 are spatially related to conventional apatite-less albitites. The former ones are formed inside the bodies of the latter ones as zones with thickness up to a few score of meters. Observed length of bodies of albitites rich in apatite is hundreds of meters. The apatite-bearing albitites have increased radioactivity of thorium- or mixed origin. They have anomalous grades of P, Th, REE, Y, Zr, U. For most of the elements a relation to certain minerals is identified. It is an apatite in respect to phosphorus. High Th grades are due to thorite. All features of apatite-bearing albitites listed above differ from conventional uranium-bearing albitites. The latter ones are always of uranium origin with low-grade P, and REE, Y, Ве, Zr. The ore occurrences of apatite-bearing albitites of Novokostiantynivka ore field and Kirovohrad ore district can be compared to the famous Itataia uranium-phosphorus deposit (north-eastern part of the Brazil Shield). It belongs to albitite type deposits and is confined to marble layers and metamorphic rocks of Early Proterozoic. They also can be compared to similar occurrences of the Zhovta Richka deposit of the Kryvyi Rih.

Organization of monitoring of plant cover during the development of deposits of precious metals using the example of objects of the Malmyzh ore field

Organization of monitoring of plant cover during the development of deposits of precious metals using the example of objects of the Malmyzh ore field