Mineralogical Journal

3-16

Authors: V.M. Kvasnytsya

Summarized data on more than 120 diamond crystals from the Neogene (Baltska suite) and Quaternary alluvial sediments of the Dniester — Southern Bug interfluve and their basins were studied: 35 microdiamonds and 1 macrodiamond from the Neogene (Baltska suite) sands and 85 microdiamonds from alluvial sands. Using infrared microscopy, Raman spectroscopy and isotopic analysis of carbon a little more than four dozen microdiamonds (less than 0.5 mm in size) and one macrodiamond have studied in details. According to morphology, microdiamonds from the Neogene (Baltska suite) sands are mainly represented by cubes, octahedrons and rhombic dodecahedrons, as well as crystal fragments. Their photoluminescence is orange, green and yellowish green. Almost half of the crystals do not show luminescence under ultraviolet light. The macrodiamond and several microdiamonds are nitrogen-free crystals of type IIa by physical classification. According to Raman spectroscopy, they are relatively structurally more perfect than nitrogen-containing crystals. Microdiamonds from the alluvium of the Dniester and Southern Bug basins are represented in almost equal proportions by octahedrons and rhombic dodecahedrons, cubes and combination crystals, as well as crystal fragments. Photoluminescence of these diamonds is often orange and green, less common blue and yellow, and is absent for a significant part of the crystals. Among the investigated microdiamonds from the alluvium sands, 39% of the crystals are nitrogen-free type IIa diamonds, 31% of the crystals — Ia type diamonds, 15% of the crystals — Iab type diamonds and 15% of the crystals — Іb type diamonds. Microdiamonds from the alluvium of the Dniester basin have a wide range of δ13С values: from –24.79 to –3.14‰ (average –11.94‰). A specific feature of the microdiamonds of the Dniester — Southern Bug interfluve and their basins is the wide distribution of unique green rounded crystals among them — tetrahexahedrons and rhombic dodecahedrons. They are characterized by a high content of single nitrogen impurities (593—1106 ppm), a low degree of aggregation of nitrogen atoms (0—13%), and a narrow range of carbon isotopic composition values (average –11.53‰ δ13С). They are classified as endemic diamonds, which features indicate their local indigenous sources. The distribution of green microdiamonds was analyzed and an assumption was made about their genesis and the possible finding of their host sources. Issues of the origin of diamonds of the Dniester — Southern Bug interfluve and their basins, their possible crystallization medium, and host rocks are considered.

27-38

Authors: О.М. Ponomarenko, A.I. Samchuk, I.M. Lisna, L.V. Somka, I.A. Shvaika, L.I. Proskurka, I.D. Shvaika, K.V. Vovk

As a result of studying of the distribution of rare earth elements (REE) in apatites from metamorphic rocks that occurr as xenoliths (skialites) among Berdychiv granites and charnockites of the Podilsk block of the Dniester-Bug Megablock of the Ukrainian Shield, it was found that apatites of granulite-gneiss rocks are characterized by a low fractionation of REE with predominant light REE and sharp deficiency europium, which is characteristic of calc-alkaline rocks of other shields. As to the metamorphic rocks of the Bereznin stratum the maximum content of REE found in apatites is characteristic of melanocratic rocks which commonly found in the central zones of metamorphic xenoliths. At the contact with granitoids the content of REE decreases. All xenoliths became zonal due to the such factor as acid-basic ratio that control the differentiation of REE in mineral-forming environment. It has been suggested that the spectra of REE distribution found in apatites from metamorphic rocks, which occur as of xenoliths among granitoids, may indicate the nature of xenoliths. They can be either the substrate for these granitoids or occur as dyke or restite formations.

50-68

Authors: L.M. Stepanyuk, L. Shumlyanskyy, V.O. Gatsenko, T.I. Dovbush, S.A. Wilde, А.А. Nemchin, B. Bagiński, O.V. Bilan

The LA-ICP-MS method has been applied to the investigation of U-Pb and Lu-Hf isotope systematics in zircons from enderbitic gneiss that represents the main rock type in the Kosharo-Oleksandrivka open pit, and from amphibolite (metamorphosed ultramafite) that occurs as a body of non-defined shape hosted by enderbitic gneiss. The multigrain TIMS U-Pb dating method was applied to monazite from a charnockite vein that cuts through enderbitic gneiss. At least three zircon populations can be defined in enderbitic gneiss. The oldest (Paleoarchean) population is rather small and includes zircons that yielded an upper intercept age of 3325 ± 42 Ma. The biggest (Mesoarchean) population embraces zircon grains that plot along the regression line with the upper intercept age of 2850 ± 18 Ma, and lower intercept at 2092 ± 45 Ma. The Paleoproterozoic population plots near the lower intercept of the above mentioned regression line, its age has been defined as ca. 2100 Ma. The εHf value in zircons of the Mesoarchean population varies from 1.9 to –7.7, with a single value as low as –16.4. Paleoproterozoic zircons have εHf in a range –7.7 to –18.4. Amphibolite hosts two zircon populations. The first one has an upper intercept age of 2840 ± 31 Ma and variable Hf isotope composition (εHf — 7.7 to –9.9) that indicate mixing of juvenile mantle-derived and ancient crustal materials. The second population comprises a few zircons of the Paleoproterozoic (2078 ± 24 Ma) age that also had a mixed mantle-crustal source (εHf — 5.2 to –7.9). The late vein of charnockite yielded the U-Pb monazite age of 2015.3 ± 7.2 Ma. According to geothermobarometry, based on mineral composition determined by electron microprobe data, the studied rock association experienced granulite facies metamorphism at a temperature of 720—825 °С and pressure of 6.2—7.5 kbar.

3-13

Authors: I.M. Naumko, L.M. Stepanyuk, H.O. Zankovych, O.B. Vysotsky, I.M. Kotvitska

Тhe strontium isotope composition was determined for the first time for vein calcite in Oligocene deposits of the flysh formation, north-western part of the Krosno structural-facial unit of the Ukrainian Carpathians. The measured 87Sr/86Sr ratios vary from 0.70 864 to 0.71 030 and do not show any correlation with the location of veins in outcrops, sampling point, composition and age of host rock. They are plotted within the interval characteristic of continental crustal rocks and almost completely coincide with 87Sr/86Sr values (0.708—0.7095) typical of present-day seawater. At the same time they clearly differ from 87Sr/86Sr mantle values as well as values of continental carbonate rocks. It can indicate fundamentally different sources for these fluids and fluids from mantle and continental carbonate rocks. Veinlet-disseminated mineralization is treated to be associated with tectonic activization, influx of deep fluids and formation of mineral paragenesis in veinlets and disseminations by healing of cracks in zones of fracturing and crushing. Therefore fluids are enriched in radiogenic 87Sr up to typically crustal values, what reflects the essential importance of the crustal material in calcite formation. The range of values 87Sr/86Sr ratios obtained is similar to those determined for oil samples of collected from a number of pre-Carpathian fields (0.7084—0.7109). This fact additionaly proves the conjuncting nature of processes of vein filling, dissemination and of hydrocarbon formation within the Carpathian region. It also indicates common crustal source of deep migrating hydrocarbonrich fluids, which inflow into the so-called zones of the development of sealed reservoirs promotes formation of oil and gas fields in favorable geodynamic conditions.

20-31

Authors: K.V. Repina, T.P. Volkova, V.M. Zagnitko, V.S. Moroz, L.I. Proskurka

The article presents results of geochemical features of carbonate rocks and ore associations of the zone between the Donbas and the Priazov megablock of the Ukrainian Shield, in particular, the Novotroitsk deposit and adjacent areas. The Novotroitsk deposit consists of a number of blocks bordered by faults from all sides. The northern boundary of the deposit runs along the western ending of the South-Volnovakha fault zone. In the south, the site is bordered by sub-latitudinal Dolomite fault, and the western border coincides with the Velyko-Anadol fault. Ore mineralization in the deposit is represented by Cu, Pb, Zn, Mo and other sulfides. Sulfide mineralization occurs both in veins and as phenocrysts of pyrite, chalcopyrite, bornite, arsenopyrite, chalcosine in the groundmass of carbonate rocks. In quartz veins and breccia zones phenocrysts of molybdenite are present in association with chalcopyrite, galena, sphalerite. Fluorite mineralization was found in carbonate rocks of single wells of the Novotroitsk deposit, that are located near the Velyko-Anadol fault. Isotope-geochemical studies of carbonate veins, veinlets and host rocks, with taking into account various geochemical and mineralogical features, made it possible to identify several groups of carbonate paragenesis that correspond to the mineral formation stages. The first stage of mineral formation resulted from the dynamics of the marine regime occurred within the zone between the Donbas with the Priazov block in the Carboniferous. Samples of ordinary limestones of the Novotroitsk deposit have composition of stable oxygen and carbon isotopes that is typical of carbonates. The presence of negative δ13C values indicates a change towards more recovery conditions of marine regime, which is characteristic of the Early Visean C1 va. The second and third stages of mineral formation are associated with phases of tectonic-magmatic activization (during Devonian and Permian- Triassic). In general, medium- and low-temperature ore-forming hydrothermals prevailed. With increasing temperature, water was evaporates from carbonates, interacted with the host rocks and turned into a mineral-forming fluid. On passing through permeable fractured, brecciated carbonate rocks, it promoted the redeposition of carbonate material and the formation of ore minerals. The range of changes in the isotopic composition of these carbonates varies widely depending on the mineral formation temperature. The subsequent stages of mineral formation occurred during the processes of multiple dissolution-redeposition of carbonates. These carbonates are associated with tectonic block dislocations of the zone and the circulation of solutions in permeable areas. In this case, abiogenic redistribution of carbon isotopes occurred, when the heavy 13С isotope was accumulated in residual carbonates, and lighter fractions removed from mineralization zones.

46-62

Authors: L.M. Stepanyuk, L. Shumlyanskyy, A. Hoffmann, M. Hofmann, A. Kovalick, A. Bekker

Convincing geochronological data regarding the time of accumulation of deposits that fill the Kryvyi Rih structure, Ukraine, are still lacking, and in the current hronostratigraphic chart they are attributed to the Paleoproterozoic. Thus, dating of detrital minerals that allows determination of the maximum age of sedimentation, is especially important. The paper presents results of the U-Pb LA-ICP-MS dating of zircons from two quartzite and two phyllite samples from the Kryvyi Rih structure. Three of these samples are from metaterrigenous sediments of the Skelyuvatka Suite, whereas one sample was collected from the Saksagan Suite. The study was carried out applying LA-ICP-MS method. Most of the obtained results are highly discordant due to the high degree of metamictization caused by high concentrations of Th and U. Only results of U-Pb dating with the degree of concordance higher than 80% were further considered. Zircons from all four samples yielded ages that fall within a narrow interval of 2.9-3.3 Ga that corresponds to the age of the basement rocks of the Middle Dnieper Domain that underlies the Kryvyi Rih structure. The youngest measured age of ca. 2.9 Ga corresponds to the maximum sedimentation age of the Saksagan and Skelyuvatka Suites. Within error this age also corresponds to the age of detrital monazite (2.85 Ga) found earlier in sandstones of the Skelyuvatka Suite. It is somewhat younger than the age of metamorphosed basalts of the New Kryvyi Rih Suite (2.96 Ga), whose outpouring indicated initial formation of the Kryvyi Rih structure. The earlyer defined age of granites of the Hannivka massif (2.68 Ga) that cut through deposits of the New Kryvyi Rih and Saksagan suites, also confirms their at least Neoarchean age. Currently available geochronological data indicate Meso- to Neoarchean deposition age of the New Kryvyi Rih, Skelyuvatka and Saksagan suites.

74-89

Authors: О.М. Ponomarenko, E.М. Sheremet, М.А. Kоzar, L.V. Shpyliovuj, S.М. Strekozov, I.Yu. Nikolaev, S.G. Kryvdik,L.D. Sietaia

The geological structure of the Mazurov, Azov, and Anadol deposits (Ukrainian Shield, Eastern Azov region), the structural and tectonic conditions of ore localization and their mineralogical and geochemical types are presented. The distribution and concentration of rare elements including rare earths (REE) in ore bodies is given. The balance reserves of ores and the estimated resources of zirconium oxides, REE, niobium and tantalum in these deposits have been calculated. The technological aspects of ore enrichment and processing are considered. The results of the calculation of the expected technical and economic indicators of the development of deposits in the mining unit are presented. The feasibility and investment attractiveness of the creation of a mining association in the southeastern Azov region is economically justified. On the basis of the Donetsk chemical and metallurgical plant (DCMP, in the Donske, Volnovakha district) the creation of an industrial complex (mineral deposits association) is proposed, capable of processing stale tails of DCMP and ores of the Mazurovka deposit by means of "Tantalum-niobium enterprise" and its structural unit "Rare-earth mining enterprise" targeted for mining ores of Azov and Anadol deposits. The objective of the industrial complex is to carry out a complete closed cycle of work within the above mentioned ore deposits, starting with exploration, development, enrichment, production of commercial products in the form of concentrates, and ending with their deep processing to obtain the necessary final products, as well as their implementation in domestic and foreign markets. The creation of additional small exploration and production enterprises for the extraction of other types of raw materials is envisaged that ensure the work of technological processes of the industrial complex. The mineral deposits’ association will be the base enterprise for the creation of the REE industry of Ukraine, ensuring the use of strategic types of mineral raw materials — rare metals — as one of the important indicators of the level of development of the country’s economy.

3-11

Authors: V.I. Pavlyshyn, D.K. Voznyak,

The Volyn chamber pegmatites in Korosten granites are continued to the zone in which the products of degassing of acid and basic fusions entered in chambers of free growth of crystals over a long period of time. Topaz is the most famous mineral in the Volynian pegmatites. The characteristic morphology of topaz from the Volynian pegmatites is of ten flattening of the crystals in a direction perpendicular to the prism face {110}. As a result, the extremal symmetry is not perfect (dissymmetrization). On the example of dissymmetrized topaz crystals, such a collision is clearly defined: the concept of a crystal, in the case of its dissymmetrization, loses the value of a mineral individual, acquires a heterogeneous structure, which corresponds to the loss of the main properties of the crystal — homogeneity and anisotropy. For such dissymmetrized crystals the term "anomalous monocrystal" is proposed — a visually homogeneous crystal whose individual growth pyramids belong to different spatial symmetry groups at the micro level. The theme "Fluid flows and morphology of mica and topaz" in the chamber pegmatites of Volyn’ is presented comprehensively through the prism of symmetry-dissymmetry. The conclusion is that the columnar crystals of Li-Fe mica (sometimes without pinacoid {001}) are a consequence of the active interaction of two symmetries (the Curie principle) — the fluid flow and the crystal. Dissymmetrization of topaz crystals was carried out under the conditions of one-sided flow of deep fluid flows with symmetry of the "arrow".

24-35

Authors: D.K. Voznyak, V.O. Syomka, V.M. Belskyi

By convention, the information about the PT-parameters of mineral formation obtained by fluid inclusions study is classified into basic and additional. The former is based on studying the genetic nature of inclusions of homogeneous and heterogeneous capture that are homogeneous and heterogeneous in origin (according to V.A. Kalyuzhnyi). It forms predominant data set on the PT-parameters of mineral formation. The latter, additional information substantially supplements the basic information. It is obtained by studying inclusions refilling and cracking , variations in chemical composition of the mineral substance re-deposited on the walls of the inclusion during the acquisition of the equilibrium form of the negative crystal as well as the study of inclusions with "cap". These are inclusions of new type that have indicator (typomorphic) value. It should be noted that, in general, there are rare examples of application of volatile components inclusions that are homogeneous in origin for reconstruction of PT-conditions of mineral formation. It is not easy to find a point on the isochore that corresponds to the inclusion content and it should be done in separate way by determination of either temperature or pressure. Sometimes there are cases of direct determination of the RT-condition of mineral formation. The solution of such cases might be done through estimation of fluid pressure at formation of metamorphic mineral; determination of the overheating degree of inclusions in quartz from Volyn chamber pegmatites and the depth of pegmatites formation; revealing the role of high-thermobaric CO2 fluid flows in the formation of the Mayske gold deposit; studying the genesis of quartz-albite-petalite pegmatites in the western part of the Ingul megablock as well as REE-U-Th ores of Dibrova deposit (Ukrainian Shield); formation of inclusions with a "cap".

49-65

Authors: O.V. Dubyna, S.G. Kryvdik, O.A. Vyshnevskyi

Alkaline granites and their hypabyssal and effusive varieties have a limited distribution on the Ukrainian Shield, unlike other Precambrian platforms and shields. Grorudite dikes in the Eastern Azov region have discrete chemical and mineral composition and are considered as analogues of alkaline granites — pantellerites (high-Ti or aegirine type) or comendites (low-Ti or amphibole type). High-Ti grorudites are highly enriched in incompatible elements (REE, Zr and Nb) in comparison to low-Ti type. As a result of high-Ti grorudite investigation, new for these rocks titanium minerals (titaniferous hematite with high MnO content, minerals of the FeTiO3–MnTiO3–ZnTiO3 series), previously unknown in these rocks Ca-Na-amphiboles, as well as structural relationships between aegirine and alkaline amphibole were revealed. Despite of high or increased content of HFSE in grorudites, information about their accessory minerals is quite restricted. In the aegirine-bearing varieties of grorudites, such rare elements minerals: monazite-(Ce), bastnäsite-(Ce), britholite-like mineral and REE-enriched apatite, zircon, a Na-rich mineral similar to calciocatapleiite, as well as unidentified zirconium minerals and minerals of the aeschynite group were recognized. In amphibole-bearing dikes zircon and Nb-bearing rutile were only found. These minerals are often very small in size, the largest of them can reach 15—20 μm in size; mostly do not exceed 10 μm. It greatly complicates their identification. An interesting and unusual fact is that many of rare minerals, especially bastnäsite-(Ce), aeschynite group minerals and zircon are present as inclusions in titaniferous hematite. It is assumed that a significant part of rare metals isomorphically incorporate to rock-forming minerals (alkaline pyroxenes and amphiboles). Some of rare minerals (especially zirconium ones) are secondary mineral and were formed as a result of replacement of primary Na (eudialyte, catapleiite, hilairite) or Ca (gittinsite, calciocatapleiite) Zr-silicates, which are more typical in peralkaline (agpaitic) rocks. Taking into account the petrological features and the nature of the rare-earth mineralization of grorudites of the Eastern Azov region, there is a reason to believe that such type of mineralization in these rocks occurs in course of differentiation of the initial magmatic melt(s). Such melts are similar to high-Ti basalts (characteristic rocks of this region) of Devonian age. Secondary hydrothermal processes are weakly manifested in the studied rocks and probably led to substitution of primary accessory minerals. Considering the increased or high concentrations of Nb in high-Ti grorudites and an insignificant amount of Nb-minerals, it is likely that differentiation conditions (low F, high f O2 and hypabyssal conditions of crystallization) did not promote prolonged crystallization with significant accumulation of rare-metal minerals. However, the presence of grorudites with high content of rare metals found in this region increases the prospects for discovery of small alkaline granite intrusions (holocrystalline analogues of grorudites) which may host deposits and/or occurrences of Nb, REE, Zr, Sn, Be.

76-85

Authors: V.O. Pryvalov, O.A. Panova, А.V. Pryvalov

The Donets Basin or Donbas frames one of the major late Palaeozoic coal-bearing basins in the world. Geologically, the basin stands out by its thick sedimentary column containing prolific coal-bearing measures. Within the domain of the Donbas Foldbelt, it is characterized by prominent inversion-folding patterns controlled by principal displacement zone (PDZ). Historically, the Donbas region has served as a heartland of Ukrainian industry including coal and mercury mining, multiple metallurgical and chemical processing plants. Because of tremendous amount of organic matter became thermally mature the basin hosts unconventional gas plays including "shale gas" and coal-bed methane resources, which may be served a resource base to cease the Ukrainian dependence on gas imports from the Russian Federation through unconventional gas developments. Nowadays, this geological and economic-geographical region suffers from military hostilities, which may have unpredictable consequences and threaten the security of adjoining regions. The aim of this publication is to ascertain the threat of a dramatically deadly combination of historically persistent man-made environmental damage and armed conflict which affected surface terrain and underground environment, urban and infrastructural facilities, lands and agricultural development within the Donbas region (Eastern Ukraine). We used the extensive dispersed long and short-term observation data collected and acquired in the Donets Basin in order to describe, classify and retrieve the most pressing environmental concerns, as well to delineate future goals for its forthcoming recovery. A scope of environmental problems is given with special stress on interval from 2014 up to the present time including delineation of risks related with specific geostructural position of "Cleavage" underground nuclear blast site and induced seismic activity reported within Khanzhonkovo site (Obyedinenyi settlement) of Makiivka region in 2019. Methods of detection and prevention are described and the potential size of the problem is assessed. The scopes of remedial measures that may be taken are discussed.