Mineralogical Journal

21-40

Authors: T.M. Lupashko, A.N. Tarashchan, K.O. Ilchenko, E.E. Grechanovskaya

A study was carried out in order to identify the aspects of geochemical processes occurring during the formation of green and light-blue amazonite crystals. Green, light-blue and greenish-blue amazonites from rare-metals deposits of Ukraine (Perzhanske, Ukrainian Shield), rf (Gora Parusna, Ploskogirske, Kola Peninsula; Orlovske, Western Transbaikalia), and USA (Rutherford, Virginia) were investigated using X-ray luminescence (XRL), infrared (IR) spectroscopy and X-ray diffraction. The rock-forming microcline from the Perzhanske, Orlovske and Katuginske (rf) deposits was also studied. It was found that the multi-colored crystals of amazonite have similar degrees of Si/Al ordering. They are represented by the maximum microcline with 2t1 = 0.959-1.0. The various samples only differ significantly in their lead contents that range between 2000 and 10000 ppm in green amazonite and 200 ppm in light-blue colored crystals. Differences between untreated crystals and those annealed in air (1173 K) or under a stream of He (923 K) samples were observed in terms of the composition, ratio of optically active centers and oxygen-hydrogen defects. Their composition and concentration in the untreated natural crystals reflect the genesis conditions of parent rocks, and, first of all, the redox and fO2 conditions of water-containing fluids, which affect the isomorphism of plumbum in the structures of the green and light-blue crystals, mechanisms of crystal chemical compensation of Pb2+ ions and correlates with different degree of ferum oxidation (Fe3+ → Fe2+). Changes in redox and fO2 parameters of the mineral-forming fluid are the most important factors affecting the activity and acid-base properties in the residual water fluids, the process of reduction following 2H2O + 2e– → H2 + 2OH– or oxidation via 2H2O – 4e– → O2 + 4H+. A complex combination of these factors allows the formation of certain nanosized defects in the structures of the amazonite crystals. These include impurity ([Pb2+ – Pb+]3+) and impurity-vacancy (Pb2+ – VK) clusters that serve as chromophore centers for green and light-blue color, respectively.

50-58

Authors: A.L. Larikov, O.V. Zaiats, M.M. Bagmut

The electronic paramagnetic resonance spectra of microfractions of microcline, plagioclase and albite from the Ruska Polyana granites of the Korsun-Novomyrhorod pluton located in the Ukrainian Shield were measured. The results are used together with chemical and X-ray fluorescence analyzes to study the nature of Fe and Mn in the feldspars. It is shown that structural Fe3+ in the microcline and plagioclase reflect the iron content in the melt during crystallization of the granite. At the same time, nonstructural impurities of Fe3+ and Mn2+ in the feldspar monofractions, which are part of hydroxides and carbonates along grain boundaries, do not show correlations with structural impurities of Fe3+ replacing Al3+ ions in microcline and plagioclase, and presumably reflect postcrystallization processes. The ratio of the intensities of the Fe3+ EPR lines in the spectra of microcline indicates that its ordering temperatures are close to 670 K for all studied samples.

72-82

Authors: V.G. Verkhovtsev, O.G. Musich, Yu.O. Fomin, Yu.M. Demikhov

Prospects for increasing the raw materials resources of uranium ore deposits of the albite formation of the Ingul megablock of the Ukrainian Shield and the possibility of reducing the impact of harmful waste due to the method of bacterial leaching of metals were considered. Mineral-forming systems of uranium-bearing albitites of the Ukrainian Shield have always been considered as monoelement, exclusively uranium objects. However, their out-of-balance ores and tailings contain elevated, up to industrial, concentrations of other metals, which, under conditions of hypergenic processes, pose a potential threat of environmental pollution. In order to determine the possibility of expanding raw materials resources of albite deposits of the Ukrainian Shield due to the use of the method of bacterial leaching of metals, the composition of industrial ores and host rocks was considered. In particular, our data from their mineralogical and geochemical research showed that uranium and five of its companion elements: thorium, vanadium, beryllium, zirconium and lead reach industrial content. At the same time, cobalt, nickel and zinc are characterized by an increased content close to the minimum industrial values. The most promising for bacterial leaching are rocks that contain sulfides. The rocks of the uranium ore albitite formation contain sulfur-containing compounds and, in particular, pyrite, as well as bi- and trivalent iron. We found the highest content of sulfides in albitized rocks (up to 0.82%), ore-free albitites (up to 0.81%), low-ore albitites (up to 0.61%), that is, in rocks accumulated in industrial waste. It is assumed that the use of bacterial leaching methods with the participation of chemolithotrophic microorganisms can be promising for the processing of off-balance ores and will contribute to the expansion of the raw material base of albite deposits of the Ukrainian Shield, due not only to uranium, but also to nickel, cobalt and zinc.

95-109

Authors: V.M. Kvasnytsya

The diamond mineralogy from a number of different non-kimberlitic occurrences of the world was analyzed and a comparison to diamonds from Neogene placers of Ukraine was made. Diamonds from lamprophyres of the Canadian Shield, metakomatiites of the Guiana and West African Shields, and ultra-metamorphic rocks in Asian, European and African continental occurrences were considered. In general, Ukrainian Neogene placer diamonds have many similar mineralogical features to diamonds from lamprophyres and metakomatiites, which differ little from diamonds from kimberlites and lamproites. Ukrainian placer diamonds are characterized by their micron sizes (≤0.5 mm), many of them are colored and have a cubic habit and nitrogen-free compositions, relatively frequent spectral Ib and Iаb types, and orange photoluminescence behavior. In addition, many diamonds are characterized by a relatively high content of hydrocarbons (i.e., CH2, CH3 groups and bonds >C=CH2), OH groups, also C=O, N-H, CO3, NO3-groups. This is evidence for a volatile-rich environment during the diamond crystallization. The formation of diamonds from lamprophyres and metakomatiites, as well as from kimberlites and lamproites, occurred under mantle temperatures and pressures. The relatively recently discovered diamond-bearing lamprophyres and metakomatiites have a number of similarities. They are: i) both formed on the edges of Archean cratonic structures, ii) their old ages (2.7 billion years ago and 1.83 billion years ago for the lamprophyres and 2.2 billion years ago for the metakomatiites), iii) both are strongly metamorphosed, iv) both contain many fragments of rocks of various origins, v) both contain rare xenograins of mantle minerals having diamond-bearing peridotite and eclogite associations, and vi) the diamonds themselves are often microcrystals and many are colored and have a cubic habit. The main difference between diamonds from the lamprophyres and metakomatiites is in their carbon isotopic signatures and their thermal history in the mantle. This is expressed by their different nitrogen contents and the different degree of its aggregation. Diamond-bearing ultrametamorphic rocks are mainly Paleozoic-Mesozoic in age (i.e., 531-92 million years) and occupy a tectonic setting at convergent plate boundaries unlike diamond-bearing lamprophyres and metakomatiites. Diamonds from ultrametamorphic rocks differ from diamonds from lamprophyres and metakomatiites as well as from Ukrainian placer diamonds from Neogene sands in a number of ways.

22-34

Authors: V.I. Pavlyshyn, D.S. Chernysh, H.O. Kulchytska, O.I. Matkovskyi

Some regularities of the interrelation of the genesis and minerals distribution in the bowels based on the analysis of information on the temporal and spatial distribution of minerals in geological complexes, primarily in Ukraine, were revealed. The distribution of minerals in magmatic complexes, pegmatites, hydrothermalites and metamorphites was studied. The relationship between tectonics and the distribution of minerals is noted. There is a clear direction of the geological development of the earth's crust: the pacification of tectonic processes — the growth of platforms — the differentiation of mineral matter. The number of formed mineral species increased rapidly from Archean to Phanerozoic complexes, from "basaltic" to "crustal" mineral formation, from ultrabasic rocks to acid ones. The Pre-Greenstone crust of Ukrainian Shield (USh) is predominantly represented by plagioclases and pyroxenes; with the development of granitoids, quartz and alkali feldspars joined them. From early to late stages of USh development, the number of species increased by an order of magnitude. Near-Azov megablock is in the first place. Maximum species formation is associated with alkaline magmatism and processes involving volatile components, in particular pegmatite formation. The number of minerals in pegmatites reaches hundreds of species. Mountain building led to the destruction of igneous rocks and the formation of new minerals. The appearance of free oxygen became a powerful factor in mineral formation. Superimposed processes with the supplying of deep fluids contributed to the transformation and redistribution of minerals and the formation of polygenic ores. The distribution of minerals makes it possible to detect typomorphic species for certain processes, which can be used to determine the criteria of mineralization, its scale, and the erosion section of ore bodies. The distribution of various mineral species, and the same species with identified macro- and microdefects, as a result of the conditions of mineral formation, is of practical importance.

43-60

Authors: S.G. Kryvdik, O.V. Dubyna, V.M. Belsky

Two species types of basic rocks contrasting in chemical and mineral composition were investigated within the Korsun-Novomyrhorod anorthosite-rapakivigranite pluton (KNP) of the Proterozoic age. In comparison to more typical basic rocks of KNP, the investigated rocks are presented by the extremely Fe-rich fayalite gabbroids and the most MgO enriched biotite gabbronorite. The first of them occupy a deeper level of the Horodishche massif in the central part of KNP. According to a high-Fe association of minerals and reduced or low An content in plagioclase they may represent the crystallization of a highly evolved basic melt (after anorthosite and gabbronorites separation), which were crystallized under abyssal conditions and low oxygen fugacity. Preliminary geochemical data indicate that trace elements concentration and negligible negative Eu-anomalies (0.72-0.95) are similar to most distributed basic rocks but unlike the last it is slightly differed by decreasing La/Yb and enriched in Sc (up to 118 ppm). Thus, we suppose those rocks might be crystallized as a result of mixing highly differentiated (iron and alkali enriched) melt with the early generation of anorthitic plagioclase, with subsequent dissolution of the last. Enrichment in iron of the mafic minerals and increasing of alkalinity of plagioclase in the basic rocks is consistent with the appearance of ferrodioritic melts as a product of prolonged crystalline differentiation of the initial melt. In contrast to fayalitic gabbroids, the pyroxene-biotite gabbronorites from the border zone in according to increased Mg# of the mafic minerals and rocks are obviously the least differentiated varieties of the anorthosite-gabbronorite series. The regularities in chemical composition in such type of rocks are consistent with the liquid line of dissent for basic rocks in KNP, which implies their crystallization at an earlier stage of magma ascending. By composition, such melt can be formed at an intermediate stage from slightly differentiated melt. This is indicated by enrichment in Sr (453-881 ppm) and Ba (910-930 ppm), Eu/Eu* (0.85-1.10), increased content MgO (up to 8 wt. %), Cr and V (59-193 and 169-350 ppm respectively). At the same time these rocks are enriched in Zr and Hf (378-478 and 10.3-12.02 ppm respectively), highly enriched in Rb (169-192 ppm), with moderate Nb and Ta content (14.6-18.1 and 0.91-2.84 ppm respectively) that point out to interaction and partial assimilation by crust material. Summarizing geological data of the deep drill-holes, it is possible to reveal a general direction of the mafic minerals evolution in the basic rocks and the evidences of cryptic layering. The last are quite clearly manifested both in the large gabbro-anorthosite massifs and individual intrusive bodies. We suppose that the evolution trend of mafic mineral composition are consistent with the tholeiitic trend differentiation of the primary melt with gradual increasing of iron content (under low oxygen fugacity) during differentiation and ascending in the upper crust. According to this interpretation of the inner structure of gabbro-anorthositic massifs, on the modern erosional level of KNP are often exposed the fragments of the upper (or lateral) layered series (Fe-enriched), less often the drill-holes reach up to the heads of the lower layered series.

84-93

Authors: B.G. Shabalin, K.K. Yaroshenko, O.M. Lavrynenko, O.Yu. Pavlenko

The article reveals the regularities of the overall process of ozonolytic destruction of organic components of model drain water from nuclear power plants and sorption of imitators of the main dose-forming radionuclides (Cs — with the isotopic 137Cs label; stable isotopes of Co, Sr, Mn salts) by natural zeolite of the Sokyrnytsky deposit and sorption-reagent compounds — salts of ferrous and manganese (II). The chemical composition of the main elements of zeolite after ozonation with the addition of iron and manganese salts practically does not differ from the composition of natural zeolite. Its phase composition in the ozonation process in the presence of ferrum salts is represented by the main rock-forming mineral clinoptilolite and the secondary mineral — quartz. The main ferrum-containing phase on the zeolite surface is goethite. Secondary phases include Fe(II)-Fe(III) layered double hydroxides (Green Rust) and lepidocrocite, but their relative content is insignificant. For zeolites, after ozonation with the addition of both ferrous and manganese (II) salts, the main phases are clinoptilolite and quartz. Manganese-containing phases on the zeolite surface are represented by hausmannite Mn3O4, manganese (II) oxide, and manganese oxyhydroxide MnO(OH)2. The iron- and manganese-containing phases deposited on the surface of the zeolite in the process of ozonation are mainly characterized by a weakly crystallized or amorphized structure. The main sorbent of dose-forming radionuclides is zeolite, not the iron- and manganese-containing compounds that formed on its surface during ozonolysis. The maximum degree of sorption of 137Cs by zeolite is up to 90% when the concentration of Fe2+ is increased to 50 mg/dm3 or Mn2+ to 100 mg/dm3. The degree of cobalt sorption is 97.5% at the initial typical concentration of competing cations (Fe2+ — 5 mg/dm3; Mn2+ — 10 mg/dm3) and when Mn2+ concentration increases to 100 mg/dm3. The maximum degree of extraction of Sr2+ and Mn2+ is 99.4% and 99.9%, respectively. For effective extraction of 137Cs and Co2+ by zeolite in the ozonation process, an increase in the concentration of competing Fe2+ cations is permissible — 50 mg/dm3; Mn2+ — 100 mg/dm3 in solutions. The efficiency of extraction of Sr2+ and Mn2+ practically does not depend on the concentration of competing cations (Fe2+, Mn2+) in the drain water solutions.

102-124

Authors: V.O. Syomka, O.M. Ponomarenko, L.M. Stepanyuk, S.M. Bondarenko, V.V. Sukach, S.I. Kurylo, M.O. Donskyi

New results of mineralogic-petrographical and ore-geochemical research on Li-pegmatites and host rocks of Stankuvatka and Polokhivka ore fields of western part of Inhul megablock of the Ukrainian Shield are presented. Petrographic characteristics of host rocks, such as granites, metapelites, metabasites and ultrabasites are described. Aplite-pegmatoid granites related to Li-pegmatites have been dated as 2026-2042 Ma by means of U-Pb isotopic analysis of monazites. Li-pegmatites were formed during two stages: 1) magmatic, when formation of oreless quartz-albite-microcline pegmatites happened; 2) hydothermal-metasomatic, when residual fluid rich in rare elements affects previously formed minerals; it is reflected in presence of several generations of Li-bearing and rock-forming minerals. Initial magma was peraluminous, depleted with mafic components, and with water deficit. Albite was a first mineral crystallized in researched pegmatites. Then albite+quartz were crystallized. Then at the end microcline+quartz were formed in the central part of pegmatite veins. Petalite and spodumene were formed at the final hydrothermal-metasomatic stage. Practical importance of ores with secondary mineralization mainly presented with petalite and spodumene has been defined. Petalite ore type of Polokhivka deposit and petalite-spodumene mixed ore type of Stankuvatka deposit have a crucial role. Microprobe chemical analysis of accessory mineralization presented with triphylite, montebrasite, and other Lithium phosphates has been carried out. These minerals were detected in pegmatites and in metasomatically altered host rocks. They can be reliable criteria during geological exploration of Lithium at other locations of Shpola-Tashlyk ore district.

140-147

Authors: O.I. Matkovskyi, Ye.M. Slyvko

The mineralogical science history occupies a prominent place in academician Ye. Lazarenko's scientific and pedagogical works: in monographic summaries of regional and genetic mineralogy, five editions of the textbook "Course of Mineralogy", the famous "Mineralogical Dictionary". A number of separate articles (individual or with co-authors) are devoted to the history of mineralogy in general and Ukraine in particular. Not all of the scientist's ideas were realized during his lifetime, but students and followers of Yevhen Kostiantynovych — representatives of the scientific mineralogical school that bears his name, a member of the Ukrainian Mineralogical Society, try to continue the work of their teacher. Various aspects of the history of the development of mineralogical research are covered in specialized publications — "Mineralogical Collection", "Mineralogical Journal", "Proceedings of the Ukrainian Mineralogical Society". They are discussed at scientific readings named after Academician Ye. Lazarenko, congresses of the Ukrainian Mineralogical Society and other scientific forums. The separate chapters in modern textbooks, educational aids, reference publications are devoted to the history of mineralogical development in Ukraine and in general; in recent years a number of specialized monographic publications were published.

19-29

Authors: V.P. Semenenko, K.O. Shkurenko,Yu.O. Litvinenko

A study of the structural, mineralogical and chemical properties of another carbonaceous xenolith (K4) occurring in the Krymka chondrite (LL3.1) was made. The xenolith does not correspond to any known chemical sub-group of carbonaceous chondrites in terms of chemical composition and certain mineralogical characteristics, although its fine-grained component is similar to that of CI chondrites. Presence of graphite microcrystals makes the xenolith K4 similar to the Krymka xenoliths K1, K3, and Gr1-Gr7. Xenolith K4 has large amounts of iron sulfide. This may possibly be due to a nonuniform distribution of mineral fractions in a dusty component of the protoplanetary nebula, which could have both a local and more widespread character. During a pre-agglomeration period, K4 accumulated on its surface partially oxidized mineral dust in the same region of the gas-dust protoplanetary nebula as other xenoliths and chondrules of the Krymka meteorite. The evolution of xenolith K4 is generally similar to that of other Krymka graphite-bearing xenoliths, but differs in the relationship among minerals in the primary dusty aggregates. These features determined its distinct chemical and mineralogical characteristics and indicate mineralogical heterogeneity in the dusty component at the micro-level during the pre-accretional period of a mineral material development of the Solar system.

40-47

Authors: O.P. Vovk, І.М. Naumko, V.I. Pavlyshyn

Topaz crystal morphology and habit distortion has been studied in various mineral-structural zones of chamber pegmatites of the Korosten pluton, which is located in north-western part of the Ukrainian Shield. It was assumed that the symmetry of the crystals obey the Curie principle. This means that only the symmetry elements common to the crystal and the medium in which it is formed will remain on real polyhedrons. The types of symmetry that contain the axes of infinite order are reduced to the following groups: 1) ∞L∞∞PC is a ball; 2) ∞L∞ is a ball filled with an optically active liquid; 3) L∞∞L2∞PПC is a cylinder; 4) L∞ПС is a rotating cylinder; 5) L∞∞P is a cone; 6) L∞∞L2 is a twisted cylinder; 7) L∞ is a rotating cone. Symmetry of the real fluid-dynamic situation of the mineral-forming medium of topaz-bearing parageneses often evolves in the following way: ∞L∞∞PC → L∞∞P → P. In this case, the flow of the mineral-forming fluid has the symmetry P. The resulting topaz crystals can have P symmetry if their symmetry plane coincides with the flow symmetry plane, otherwise they have no symmetry elements at all. In particular, it is shown for the first crystals that the upper faces grew faster, and their size is smaller than that of the lower ones. Growth was limited by the supply of the necessary fluid to the growing crystal faces. Hence, it follows that the fluid flow was in the direction from top to bottom. If the planes of symmetry of the fluid flow and of the polyhedron do not coincide, then visually triclinic crystals of the second type are formed. They are much more abundant than the ones of the first type. In addition to these two types, polyhedra with external symmetry L2 are found. It is difficult to imagine an environment with such symmetry because; it is unlikely that an attached crystal would grow between two fluid streams moving in opposite directions. Nevertheless, polyhedra flattened along the faces M {110} and less often along l {120} are frequent. That is, they grew in the environment in which the fluid flow moved in a direction parallel to the {110} faces (and less often {120}), in the direction from the smaller faces of a simple forms to the larger ones. The direction of fluid flow is more difficult to establish, with more or less the same development of the faces of the simple form of the topaz crystal.

67-82

Authors: O.V. Mytrokhyn, L.I. Gavryliv, V.G. Bakhmutov

Dyke swarms that intrude Paleogene granitoids of the Argentine Islands near the Ukrainian Antarctic Station "Akademik Vernadsky" were studied. The field relations and mineralogical, petrographical and geochemical properties of the dykes allow their relative geological age and the geodynamic conditions to be clarified. The magmatic activity in the study area did not cease, at least until the end of the Miocene when the processes of orogenic uplift led to the erosive exposure of the Paleogene granitoids of the Barchans-Forge Massif. Tectonic exhumation of the latter was accompanied by the intrusion of dykes of different compositions at different depths. Cenozoic basalt and diabase dykes are the most common. Most are subvolcanic fractured intrusions formed after the complete exhumation of the host granitoids, which ended by the Miocene (11 Ma). The basaltic dykes are probably one of the youngest representatives of magmatism in the region. They have an intermediate position between high-LILE tholeiites and the calc-alkaline series. However, the nature of contamination of the basaltic dykes by crustal rocks requires additional research. Cenozoic microdiorites dykes are rarer than basaltic ones. They are hypabyssal fractured intrusions formed during the tectonic exhumation of the Barchans-Forge granitoids between the beginning of the Paleocene and the end of the Miocene (61-11 Ma). The microdiorites belong to the orogenic calc-alkaline series and they could be related to subduction processes. The discovery of only one dacite dyke indicates the rarity of acid magmatism during the Cenozoic period. It occurs as a fractured intrusion and formed after the exhumation of the host granitoids. The dacite dyke belongs to the calc-alkaline series, which, along with other compositional properties, suggests that dacite and microdiorite dykes are comagmatic.

99-110

Authors: І.М. Naumko, М.I. Pavlyuk, А.A. Loktiev, Yu.V. Khokha, Yu.A. Belеts’ka, N.H. Sava

Gases in migrating paleofluids of the Transcarpathian Basin in Ukraine proper were investigated. Their properties were analyzed using fluid inclusions in minerals and fluids occurring in closed pores of promising gas-bearing rocks. Samples were taken from wells drilled within the Mukachevo (1-Borodivsk-Novosilsk) and Solotvyno (1-Bushtyno, 4-Hrushovo, 1-Danylovo, 28-Solotvyno) depressions. According to the data from mass-spectrometric chemical analysis, methane and its homologues and carbon dioxide were found in the composition of volatile compounds, which coincides with the identified advantage of methane and its homologues, on the one hand, and carbon dioxide, on the other hand, in the natural gases of fields of the Transcarpathian gas-bearing area. Methane (98.2 vol. %), ethane (1.2 vol. %) and propane (0.6 vol. %) are found in fluid inclusions in calcite of veinlet in the rock from the well 28 of the Solotvyno structure, which includes the Solotvyno natural gas field. Only methane is found in closed rock pores. Natural gases of the Solotvyno gas field contain methane (53.86%), ethane (2.65%) and propane + butane (1.34-0.32%). СО2 contents as high as 97.3 vol. % occur in fluid inclusions in calcite of veinlets in rocks of the well 1 at Ruski Komarivtsi of the Mukachevo depression and 100 % in fluid inclusions in zeolite (?) from impregnates in rocks of the well 1 at Bushtyno of the Solotvyno depression. This can be explained by the activity of two different composition paleofluids, namely reduced or oxidating types present in bowels of the Transcarpathian Basin. They are associated with significant amount of reduced compounds (methane and its homologues) or a high concentration of oxidized compounds for their (mainly СО2). This was determined by differences in the composition of the primary high-energy abiogenic deep fluid: hydrocarbon-containing or carbon dioxide-containing. The gas composition of paleofluids indicates that two types of natural gas deposits may exist, mainly hydrocarbon or mainly carbon dioxide rich and, accordingly, the discovery of natural gas fields such as Solotvyno and carbon dioxide – such as Martovo. Hydrocarbon formation over a wide range of conditions and primary material ("oil polygenesis") allows the assessment of oil and gas resources of the region. A polygenetic approach for understanding hydrocarbon formation processes requires a changes in exploration strategy. More geochemical and thermobarometric research as well thermodynamic study of mineral-forming fluids is needed in promising geologic structures of the Transcarpathian gas-bearing area. This necessary, in order to predict possible occurrence of high-energy gas deposits and to determine areas for exploration.

11-19

Authors: S.N. Shyrinbekova

Terrestrial weathering of the Gruz'ke chondrite was investigated by considering its initial chemical, structural, and mineralogical characteristics. The spread of corrosion and degree of alteration were related to the high content of Fe-Ni metal, the phase inhomogeneity and the different concentration of Ni in the metal, as well as, the shock metamorphism features, and the residence time of the meteorite sample in a soil environment. The formation of secondary oxide veins and oxide rims, consisting of iron hydroxide pseudomorphs was caused by the selective corrosion of kamacite α-(Fe,Ni), compared to taenite γ-(Fe,Ni) and troilite FeS. A spatial relationship between shock metamorphism features, namely areas of plastic deformation, shock heating and weathering of the meteorite matter, has been confirmed. A secondary Ni-enriched phase, which contains 71.34 to 72.94 wt.% Ni, probably corresponds to awaruite (Ni2Fe to Ni3Fe) or native nickel. This phase is described for the first time as corrosion product of Fe-Ni grains in the Gruz'ke chondrite. We assume that this phase was formed during the alteration of Fe-Ni metal. Fe was removed from the meteorite metal during the corrosion process, while sulfur was introduced. The formation of iron hydroxide pseudomorphs caused changes in primary chemical and structural properties of some crystals of nickel-iron metal and troilite. Thus, the use of weathered mineral grains to interpret the pre-terrestrial conditions of the chondrite matter formation and evolution is limited. In spite of the changes in chemical and mineral composition, the corrosion products of nickel iron and troilite have consistent low chlorine content.Therefore we assume that the akaganeite β-FeO(OH,Cl) secondary phase is unlikely to form. It will prevent further alteration of the Fe-Ni metal and ensure long-term storage and preservation of the meteorite sample for further laboratory research and storage in the museum collection.

48-59

Authors: G.V. Artemenko, L.M. Stepanyuk, L.S. Dovbysh, B.V. Borodynya

The Paleoproterozoic crust formation in the Azov domain remains underexplored. In the Neoarchean-Paleoproterozoic, the Azov segment of the Archean crust was fragmented by large rift structures. This stage is associated with the formation of Neoarchean-Paleoproterozoic sedimentary-volcanic complexes of the Central Azov Series (2.76-2.22 Ga) and extensive granitoid magmatism. The research aimed at studying granitoid intrusions in the Zachativka-Fedorivka anticline in the Mangush synclinorium of the Central Azov region from the geochemical perspective. Granitoids of the Zachativka-Fedorivka anticline in the Mangush synclinorium include granitoids and later pegmatoidal granites. Plagiogranitoids are moderate-potassium rocks of the K-Na series, with predominance of Na2O over K2O and low Rb/Sr ratio (0.03). They are divided into plagiogranites with low contents of HFS elements and positive europium anomalies and granodiorites with higher contents of HFS elements and predominantly negative europium anomalies. The U-Pb age of titanite from granodiorites is 2028±47 Ma. This age corresponds to the closure of the U-Pb isotope system of titanite and thus reflects the minimum age of granodiorite. The 207Pb/206Pb age of zircon from granites is 2.07-2.09 Ga. The formation of the Paleoproterozoic granitoids of the Central Azov may be related to the activization of the mantle beneath the Azov domain during the formation of the East Sarmatian orogen at ca. 2.1 Ga. They could have formed because of partial melting of the lower crust because of underplating of mafic melts. The 2.05 Ga old vein bodies of pegmatoidal subalkaline granites, were probably formed at the stage of collision of the Sarmatia and Volga-Ural continents.

16-31

Authors: O.V. Pavliuk, V.M. Pavliuk

Rutile of the Neogene-aged Zelenyi Yar titanium-zirconium placer was studied. The average size of the rutile grains is 0.25 mm that are elliptical, rounded, short-prismatic, isometric, and elongated-prismatic crystals in shape. On the surface of the crystals, elements of physical abrasion of varying degrees, as well as chemical dissolution, are observed. The color of the rutile crystals ranges from black to yellow with black and brown being the most common. A relationship between the concentration of various impurity elements and their variations with the color of the crystals is present. The highest average content of impurity elements is recorded in green rutiles and the lowest in light brown crystals. About 61% of the rutiles contain V2O5 (30% of all crystals; average content 1.28%), Nb2O5 (25%; 1.38%), FeO (24%; 1.10%), WO3 (9%; 0.91%), ZrO2 (9%; 0.85%), Al2O3 (2%; 0.70%), Cr2O3 (5%; 0.60%), SiO2 (7%; 0.57%). The temperature of primary rutile crystallization was calculated using Zr-in-rutile thermometry and corresponds to granulite and eclogite metamorphic conditions. Cluster analysis of 284 microprobe analyses of rutile allows at least five groups of crystals to be identified. According to the chemical composition of various rutiles, it can be concluded that they originated from metapelitic rocks, enderbites, and eclogite-like rocks located in the Dniester-Bug megablock of the Ukrainian Shield.

41-55

Authors: L.M. Stepanyuk, T.I. Dovbush, O.B. Vysotsky, I.M. Lisna, O.V. Bilan

The paper discusses the results of U-Pb isotope dating of monazites and zircons from granitoids formed under PT conditions of granulite and amphibolite facies and gneisses, and crystalline shales that are like xenoliths in these granitoids of the Ukrainian Shield. In some cases, such as the Berdychiv-type granitoids and in the Zhezhelivsky quarry, the age values of monazites and outer edges of zircons coincide well; in others, such as the granites of the Ivanivsky quarry, they differ by more than the error. In the Odessa quarry, even greater differences were found between the age of zircon (1.95-1.96 ± give errors Ga) from mafic granulite, and the age of zircon (1.99 Ga) and the age of monazite (1.89-1.83 ± Ga) of a crosscutting enderbite. The U-Pb isotope system of monazite from a vein of biotite granite common in this quarry does not meet the conditions of the Ahrens-Wetherill model. The 207Pb / 206Pb age of monazite ranges from 1909.5 to 1867.0 ± 5 Ma, i.e. by more than 40 Ma. For the Sabarivsky quarry, significant differences in the 207Pb / 206Pb age values (2015.8-1984.8 Ma), which significantly exceed the analytical error, do not allow the use of the concordia U-Pb diagram to interpret the analytical data obtained for zircons from the enderbite. It is concluded that monazite is the better mineral geochronometer, compared to zircon, to determine the age of palingenetic-anatectic granitoids. Unlike zircon, which usually inherits the relict nuclei of parent rocks, relict nuclei in monazites are an exception. However, monazite is not an ideal mineral geochronometer for determining the time of endogenous geological processes. Since the crystallization of monazite is depends on the activity of calcium in the environment, in the same rock association in rocks of different composition, monazite may crystallize at different times. The combination of radiometric studies of zircon and monazite, together with zoning of their crystals, provides ample opportunities to determine the time and duration of endogenous geological processes.

71-79

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

We studied partially altered veined nepheline syenites at the Chernihivka carbonatite massif of the Azov region, Ukraine. The major minerals of the syenite are albite, altered nepheline, biotite and calcite. Fluorapatite, allanite-(Ce), monazite-(Ce), barite and stronalsite occur as minor accessory phases. The primary minerals, containing REE in the veined rocks, reflect re-equilibration in a mineral/fluid systems and recrystallization of primary rock-forming minerals. The high initial concentration of CaO, CO32–, alkalis and volatile components caused a concentration of REEs in the late differentiated portions of the phonolite melt. The intrusion of the melt into wall-rocks of different composition, together with the excees of Al and Si in solution, caused allanite-(Ce) crystallization. Subsequent postmagmatic fluids contributed to Ba, Sr and REE leaching from major rock-forming apatite and calcite and led to the crystallization of secondary monazite-(Ce), barite and stronalsite.