Mineralogy in Independent Ukraine (1991-2021)

This article discusses the state of mineralogical research in independent Ukraine in the period from 1991 to 2021. The main achievements in various Earth sciences disciplines, including regional, systematic and genetic mineralogy, the chemistry and physics of minerals, mineralogical crystallography, bio- and nanomeralogy, experimental, space and applied mineralogy, and technical studies are considered. Four world-famous research groups and disciplines are notable. They are: i) regional and mineralogical led by academician Yevhen Lazarenko, ii) thermobarogeochemical studies led by professor Mykola Yermakov, iii) crystal chemistry led by academician Oleksandr Povarennykh, and iv) mineral physics led by professors Ivan Matyash, Oleksiy Platonov, and Arkady Tarashchan. Problems facing mineralogy including personnel, scientific, and applied are briefly discussed in the "Conclusion" section.

ON THE AGE OF THE CHARNOCKITOIDS OF THE TASHLYK COMPLEX OF THE INHUL REGION OF The UKRAINIAN SHIELD

Zircons from charnockitoids of the Tashlyk complex from the Pryinhul syncline were studied and dated in order to determine their chronostratigraphic position. Zircons of two age generations were identified, namely the Early Archean (ca. 3 Ga) and the Early Proterozoic (2.0±0.1 Ga). The presence of the former generation indicates that the protolith for charnockites have been represented by the rocks older than the Spasove Series, which is considered to be Proterozoic in age. At ca. 2.0±0.1 Ga Archean rocks together with rocks of the Inhul-Inhulets Series, underwent granulite metamorphism. This event resulted in crystallization of the second (Paleoproterozoic) generation of zircon in charnockites. Archean zircons found in the rocks of the Tashlyk complex, which correspond morphologically to granitoid of the amphibolite facies, differ from Eoarchean zircons in enderbites of the Haivoron complex, which partially retain their appearance during the Neoarchean and Paleoproterozoic tectonic-magmatic events.

Age and Composition of Zircons From the Devonian Petrivske Kimberlite Pipe of the Azov Domain, the Ukrainian Shield

Results of a study of U-Pb and Hf isotope systematics and trace element concentrations in five zircon crystals separated from the Devonian Petrivske kimberlite are reported in the paper. Four zircons have yielded Paleoproterozoic and Archean ages, while one zircon grain gave a Devonian age of 383.6±4.4 Ma (weighted mean 206Pb/238U age). The Precambrian zircons have been derived from terrigenous rocks of the Mykolaivka Suite that is cut by kimberlite, or directly from the Precambrian rock complexes that constitute continental crust in the East Azov. The Devonian zircon crystal has the U-Pb age that corresponds to the age of kimberlite emplacement. It is 14 m.y. younger than zircon megacrysts found in the Novolaspa kimberlite pipe in the same area. In addition, Petrivske zircon is richer in trace elements than its counterparts from the Novolaspa pipe. Petrivske and Novolaspa zircons crystallized from two different proto-kimberlite melts, whereas the process of kimberlite formation was very complex and possibly included several episodes of formation of proto-kimberlite melts, separated by extended (over 10 M.y.) periods of time.

First Finding of the Orbicular Gabbroids in the Ukrainian Antarctic Station Area (Wilhelm Archipelago, West Antarctica)

A new occurrence of igneous rocks with an orbicular structure was discovered by the authors in West Antarctica. The place of finding is Hovgaard Island in the Wilhelm Archipelago located near the Graham Coast of the Antarctic Peninsula. Until now, not a single manifestation of these rare rocks was known in this region. Usually orbicular rocks are formed under the condition of local "coincidence" of many geological and petrogenetic factors. The study of the geological position, texture features and mineral composition of the orbicular rocks on Hovgaard Island was carried out in order to create their primary petrographic description. It was found that orbiculites are exposed in a small area, about 200 m2, in the field of amphibolized gabbroids and their intrusive breccias. The occurrence and textures of the orbiculites indicate that their crystallization occurred at the hypabyssal depth. Probably, this occurrence is a marginal facies of a small gabbroid intrusion, some parts of which are exposed on the adjacent coastal areas of Hovgaard Island. The studies performed have shown that the orbiculites of Hovgaard Island belong to the rarest petrographic representatives of these rocks namely orbicular gabbroids. In their petrographic feature, they differ markedly from the famous French napoleonites (corsites) exposed on the Corsica Island. The mineral composition of the orbicules is represented by calcium plagioclase (An88-97), hornblende (#Mg = 0.77-0.81), clinopyroxene (Wo48-50En43-47Fs5-8), spinel (Sp62-72Hrc14-20Mt12-17), actinolite, phlogopite, chlorite, magnetite and apatite. The interorbicular matrix has a gabbroid composition and a porphyritic texture. It differs from orbicules in somewhat less calcium plagioclase and less magnesian hornblende, as well as in the absence of spinel. In view of the rarity of orbicular gabbroids and the specificity of the described manifestation, it is proposed that the orbicular gabbro on Hovgaard Island be considered as a new petrographic variety of the gabbroid family. The name "hovgaardite" is recommended for the name of this variety of orbicular gabbro.

Formation Mechanism of the Velyka Vyska Syenite Massif (Korsun-Novomyrhorod Pluton, Ukrainian Shield) Derived from Melt Inclusions in Zircon

The formation of leucosyenites in the Velyka Vyska syenite massif was provoked by the liquation layering of magmatic melt. This assumption is based on the presence of two primary melt inclusions of different chemical composition in zircon crystals from Velyka Vyska leucosyenites. They correspond to two types of silicate melts. Type I is a leucosyenite type that contains high SiO2 concentrations (these inclusions dominate quantitatively); type II is a melanosyenite type that contains elevated Fe and smaller SiO2 concentrations. The liquation layering of magmatic melt was slow because the liquates are similar in density; leucosyenite melt, which is more abundant than melt of melanosyenite composition, displays greater dynamic viscosity; the initial sizes of embryos of melanosyenite composition are microscopic. Sulphide melt, similar in composition to pyrrhotite, was also involved in the formation of the massif. Zircon was crystallized at temperatures over 1300°С, as indicated by the homogenization temperatures of primary melt inclusions. The REE distribution spectra of the main parts (or zones,) of zircon crystals from the Velyka Vyska massif are identical to those of zircon from the Azov and Yastrubets syenite massifs with which high-grade Zr and REE (Azov and Yastrubets) ore deposits are associated. They are characteristic of magmatically generated zircon. Some of the grains analyzed contain rims that are contrasting against the matrix of a crystal, look dark-grey in the BSE image and display flattened REE distribution spectra. Such spectra are also typical of baddeleyite, which formed by the partial replacement of zircon crystals. The formation of a dark-grey rim in zircon and baddeleyite is attributed to the strong effect of high-pressure СО2-fluid on the rock. The formation patterns of the Velyka Vyska and Azov massifs exhibit some common features: (а) silicate melt liquation; (b) high ZrO2 concentrations in glasses from hardened primary melt inclusions; (c) the supply of high-pressure СО2-fluid flows into Velyka Vyska and Azov hard rocks. Similar conditions of formation suggest the occurrence of high-grade Zr and REE ores in the Velyka Vyska syenite massif.

Auto-Radiation Damages in Zircons of the Yastrubtsi Ore Occurrence of the Ukrainian Shield According to the Data of NMR and XRD

By the method of XRD and high-resolution nuclear magnetic resonance (MAS NMR), the features of the structure of partially metamict zircons from Yastrubtsi ore occurrence of the Ukrainian Shield were studied. Samples 1 and 2 (depths 627 and 1069 m) belong to middle metamict zircons, and sample 3 (depth 1302.5 m) — to weak metamict zircons. The purpose of this work was to elucidate the features of the structure of partially metamictic zircons from Yastrubtsi ore occurrence of the Ukrainian Shield and the features of their recrystallization. The XRD method showed the presence of diffuse diffraction bands, which indicates the presence of an amorphous phase. For sample 3, these bands are less pronounced. After heating at T = 1100°C, these bands significantly decrease. Based on the XRD data, the degree of crystallinity and unit cell parameters of the samples were calculated. To obtain information on the local structure of the samples, spectra were obtained for the initial and annealed samples. It was shown by MAS NMR that there are regions in the initial structure in which [SiO4] tetrahedra are interconnected. These regions are designated Qn (n is the number of bridging oxygen atoms per Si atom). It has been established that the silica phase is practically absent in the zircon samples. In such samples, mainly Q1-2 and Q3 polymerization of silicon atoms occurs (for sample 3, only Q1-2 polymerization is characteristic). The MAS NMR results are in good agreement with the XRD data.

GEOCHEMICAL FEATURES OF POST-PYROGENIC CHANGES OF POLISSYA SOILS (LOW FIRE)

Geochemical post-pyrogenic soil changes are one of the most important factors in determining the state of the forest ecosystem. For the first time the content of microelements (Hg, As, Ba, Mg, Mn, Mo, Cd, Co, Cr, Cu, Pb, Zn, V, Ni) in post-pyrogenic sod-podzolic soils under the pine forest of Zhytomyr Polissya (Ukraine) was determined by the ICP-MS method. The study is based on a comparison of the content of trace elements in the sod-podzolic soils of the background area and burnt areas (grassland fire in 2019). The analysis of microelements in the soil profile of the burned and background areas to a depth of 10 cm (after 1 cm) and set the limit - 3-5 cm (humus-eluvial horizon), after which you can record the accumulation or scattering of elements after a fire on the surface. By calculating the percentage change (relative to background soils), intensive accumulation (more than 20%) of elements in post-pyrogenic soils - Cu, Ni, Co, V and moderate accumulation (up to 10%) - Pb, Mo, Mg, Ba, Cr and intensive scattering - Hg, As, Cd, Zn, Mn. The increase in the pH of post-pyrogenic soils (from 4.2 to 7.5) was determined, spatial map-schemes were constructed, due to which the direction of the fire was revealed - from the south-east to the north-west. The change of the content of ionic forms of metals (Cu, Pb, Zn, Mn) in the soil solution at different pH values (from 4 to 8 with a step of 0.2) is modeled (PHREEQC program) and the current trend is revealed: Pb - linear dependence, Cu, Zn, Mn is polynomial. The pH limits are calculated, where there are free forms of metals that enter the plants: Pb 3.9-8.2; Zn 5.5-7.5; Cu 5-8.2; Mn 5-11.5. The post-fire transformation of soils was revealed, which is expressed in the increase of pH (before the fire - 4.2-4.8; after the fire - 6.5-7.2; a year after the fire - 4.5-5.5). The obtained results confirmed the need for geochemical monitoring of post-pyrogenic soils for ecosystem restoration and plant biodiversity.

Mineralogical Search Signs for Assessment of Prospects of Diamond Capacity of Ukraine (by Physiographical and Photoluminescent Data)

Some important questions concerning the application of methods of searches of diamond deposits on direct search signs - finds of diamonds are considered and indicator minerals of kimberlites (IMK). The probable reasons for the low efficiency of the dressing-mineralogical method in the search for diamond deposits in Ukraine are named. The article is based on materials of research of diamonds found in different age placers of Ukraine (~1300 crystals); diamonds from kimberlites of the Arkhangelsk province (~6000 crystals); diamonds from metamorphic rocks of the Kazakhstan deposit Kumdy-Kol (~200 crystals); Yakut province (~600 crystals from root springs and ~700 from placers). A physiographic description was made for all these crystals and the intensity and color of photoluminescence (PhL) were recorded. For some crystals, about 600 spectra were taken at a temperature of 77 K. For diamonds of the "Dniester" type and some highly defective diamonds from Ukrainian placers, data from Raman spectroscopy are given. The material on indicator minerals of kimberlites is partly the result of our research, partly attracted from literature sources. Finds of diamonds in terrigenous deposits of Ukraine, their territorial and age, possible sources of income are analyzed. The comparison of diamonds from terrigenous deposits of Ukraine with diamonds of indigenous deposits of different genetic type is performed. For comparison, we studied diamonds that were obtained (with their complete removal from the gross technological samples) from some kimberlite pipes of the Arkhangelsk province. We performed a physiographic description and established the particle size distribution and morphological distribution in these pipes. Based on these studies, convincing conclusions were drawn about the signs of the industrial diamond-bearing capacity of kimberlite bodies in this province. The study of a large number of diamonds extracted from Neogene and other placers of Ukraine allowed usto perform a comparative study not only on the morphology and color of photoluminescence but also on the frequency of photoluminescence centers (spectra were taken at 77K). These diamonds were compared with crystals from the industrial kimberlite bodies of the Arkhangelsk and Yakut provinces. It was established which physical properties of Ukrainian diamonds are close to the properties of kimberlite diamonds and how they differ, contrasting features of diamond sets of different genetic types were determined. It has been established that diamonds found in the deposits of the Bilokorovichi world have signs of kimberlite, and the nature of their surfaces, a set of PhL centers, indicates a long stay in sedimentary reservoirs of different ages. A study of diamonds and IMK, which were found on the territory of the Kirovohrad block of the Ukrainian Shield (USh), revealed that the known area of Gruzka has prospects and is worth further mineral and technological testing. The chemical composition of probable IMK from the kimberlite bodies of the Priazovsky block of the USh indicates their non-diamond-bearing or non-industrial diamond-bearing capacity, which is confirmed by a few (3 crystals) finds of natural diamonds. We found that the green microdiamonds extracted from these rocks turned out to be man-made debris. Numerous diamonds from Poltava-Sarmatian placers have specific morphology and physical properties. The source of diamonds from the Black Sea coast is the Poltava-Sarmatian placers, and the source of a few diamonds with kimberlite features has not been found on the coast of the Sea of Azov. Based on the analysis, it is concluded that the territory of Ukraine has clear prospects for the discovery of diamond deposits. Taking into account the current economic feasibility and the current degree of study of the diamond-bearing territory of Ukraine, the primary search for kimberlite sources of diamonds, in the opinion of the authors should be performed in the north-western (Ovruch-Bilokorovytsia) part, as well as within the Dnieper and Kirovograd blocks. In the course of search operations, it is necessary to abandon the analysis of IMC less than 1 mm in size and pay attention mainly to pyropes as the most informative IMC.A prerequisite for further exploration work for diamond deposits should be a large-scale mineralogical and technological test aimed at detecting diamonds with a size of at least 1.0 mm limiting the size of the studied fractions will allow not only to reduce costs, but also to determine the feasibility of the search.Only based on the results of these works it will be possible to concludethe prospects of the industrial diamond-bearing capacity of the allocated areas.

Mineral Waters of the Eastern Ukraine

This article considers the distribution, formation, and chemical composition of mineral waters of the Eastern region of Ukraine, and, in particular, Donetsk, Luhansk, and Kharkiv regions. The main types of mineral waters, most characteristic of the Eastern region of Ukraine, are determined. Their formation and distribution are considered. Manifestations of ferrous, bromine, boron and iodine waters have been studied in this region, which significantly expands hydromineral and balneological resources. The application of ferrous mineral waters to organisms exposed to radiation has been studied. Since one of the consequences of radiation damage is a violation of oxidative homeostasis, the effect of ferrous mineral waters on the course of free radical processes in the body was studied. The peculiarities of the organic composition and biological properties of Berezivsky mineral waters have been studied to identify them as Naftusya-type waters. It is established that Berezivsky mineral waters do not have a pronounced radiomodifier effect. They are inhibitors of the enzymatic activity of catalase — a key regulator of oxidative metabolism, which leads to a deterioration in the vital functions of the body after irradiation. According to the obtained data of mass spectra, active organic substances of different classes, which are part of mineral waters of the Naftusya type, differ from organic substances of Berezivsky mineral waters, both qualitatively and quantitatively. Therefore, Berezivsky mineral waters cannot be referred to as the class of mineral waters of the Naftusya type. Some studies were also conducted and an array of statistics was obtained, which showed that the mineral waters of the Podilsk region, Naftusya and Berezivsky waters have pesticide concentrations less than 0.01 ng/dm3, i.e. 10 000 times lower than their permissible concentrations according to international standards. This confirms the possibility of widespread use and export of Ukrainian mineral waters, which is of national importance. Prospects for the development and use of mineral waters in the Eastern region are shown.

About Diamonds of the Ingul-Ingulets Domain (the Ukrainian Shield)

Three finds of diamonds on the Ingul-Ingulets domain of the Ukrainian Shield are considered: in breccia-like rocks of the Gruzke area, in eclogite-like rocks in the basin of the Ingul River and the Zeleny Gayi meteorite crater. A brief description of these diamonds is made, which represent their different geological and genetic types. Тhe veracity of these diamond findings and the origin of their crystals are appreciated. It is shown that 8 diamonds of the Gruzke area differ in size (0.2-1.4 mm), shape, colour, set of nitrogen centres and degree of preservation. According to infrared spectroscopy, all the studied crystals can be attributed to natural diamonds of the mantle type and distinguish them into separate groups, as they belong to several spectral types: IIa, IaAB, Iab and Ib. However, there are several doubts about the veracity of this finding: 1. Finding in small samples of the core wells of such a high concentration of diamonds. 2. A large variety of crystals in these samples by spectral types of physical classification. 3. Signs of mechanical wear on all crystals, which does not exclude the version of their origin from a diamond drill bit (a mixture of crystals of the natural and possibly synthetic diamond). The question of whether the found diamonds belong to the breccia-like rocks of the Gruzke area remains open. Small diamonds (up to 0.3 mm), which are found in eclogite-like rocks in the basin of the Ingul River on several grounds (mainly cubo-octahedral habit, manifestations of skeletal forms of growth, flat surface of the cube faces, yellow-green colour, inclusions) are very similar to crystals of synthetic HPHT diamond. However, the same small diamonds are found in the rocks of the Euro-Asian Alpine and the Ural and Central-Asian Caledonian ophiolite belts and the eruptions of modern volcanoes in Kamchatka. Such diamonds are also found in lamproite-like rocks of the Mriya pipe in the Azov Sea region, and they are found in weathering crusts and terrigenous deposits of Ukraine. It is necessary to find out the true nature of these findings. Therefore, it is necessary to audit all finds of such diamonds in Ukraine. It is shown that diamonds from the Zeleny Gayi meteorite crater are typical impact apographitic crystals - diamond paramorphoses on graphite. The conclusions of some researchers about the mantle nature of these diamonds from this crater are denied.