Zincian micas from peralkaline phonolites of the Oktyabrsky massif, Azov Sea region, Ukrainian Shield

It was made an attempt to generalize geochemical data of Nb and Ta concentration in the most common igneous rocks of the Ukrainian Shield (USh). In the majority of widely distributed rocks of the USh (normal and subalkaline granitoids) the Nb and Ta concentration are similar to upper crust but lower the accepted Clark value for acidic rocks. In the more differentiated rapakivi granites concentrations of these elements reach or exceed the Clark’s concentrations (up to 35 ppm). Only highly differentiated alkaline rocks and alkaline feldspar granites (Perga, Kamiani mogyly, Ruska Poliana massifs) have high Nb concentrations (up to 800, 120 and 370 ppm, respectively). Medium rocks of the normal range are the least geochemically studied and typically are characterized low Nb and Ta concentrations. Almost all gabbroids as well as their metamorphosed analogues in the greenstone structures, are characterized by very low Nb (and Ta) concentration (two or more orders of magnitude) compared with Clark’s values for basic rocks (20 ppm Nb and 0.48 ppm Ta) according to A.P. Vinogradov. Against this background, increased of Nb and Ta concentration is observed in the main rocks of anorthosite-rapakivi-granite plutons. Howover even in these rocks concentration of these elements rarely reach or does not achieve the values which are typical for subalkaline and alkaline basalts of continental rifts. The regional heterogeneity in Nb and Ta distribution is observed in alkaline rocks of different composition: in the Azov Sea region these rocks are characterized by high concentrations, while in the western part of the USh the content of these elements is extremely low. The increased concentration of these elements is also revealed in kimberlites from the Azov Sea region and the Kyrovohrad megablock of the USh. The authors give some considerations and assumptions about the dependence on geochemical features of the Precambrian igneous rocks of the USh from the geodynamic conditions of their formation.

Download Full-text

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

Mineralogical Journal ◽

10.15407/mineraljournal.43.01.087 ◽

2021 ◽

Vol 43 (1) ◽

pp. 87-96

Author(s):

V.M. KVASNYTSYA

Keyword(s):

Flat Surface ◽

Ukrainian Shield ◽

Small Samples ◽

High Concentration ◽

True Nature ◽

Genetic Types ◽

Azov Sea ◽

Central Asian ◽

Physical Classification ◽

Meteorite Crater

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.

Download Full-text

Palynological data on the description of the Gelasian and Calabriane analogues in the strato- type section of the Kuyalnik deposits near Kryzhanivka village (Odessa region)

Journal of Geology Geography and Geoecology ◽

10.15421/111968 ◽

2019 ◽

Vol 28 (4) ◽

pp. 727-737

Author(s):

Olena A. Sirenko

Keyword(s):

Ukrainian Shield ◽

Palynological Data ◽

Azov Sea ◽

Stratigraphic Division ◽

Upper Cenozoic ◽

Stratotype Section ◽

Characteristic Features ◽

Palynological Study ◽

First Time ◽

Paleontological Study

The state of paleontological study of the Kuyalnik deposits of Odessa region, in particular the stratotype section near Kryzhanivka village was analyzed. Attention is paid to the absence of the palynological description of the Krizhanivka climatolith in the section and the insufficient palynological study of the liman-marine Kuyalnik sediments. The goal of the presented research was to obtain a detailed palynological description of the subaerial Eopleistocene and the liman- marine Kuyalnik sediments of the stratotype section near Kryzhanivka village. Based on the results of the research, the palynological description of rocks of the upper part of the section of the liman-marine Kuyalnik sediments is presented for the first time, as well as the materials to substantiate the correlation of the studied sediments with the Beregove and Siversk climatolyths of the continental Upper Cenozoic section of Ukraine, which correspond to the Gelasian of the International Stratigraphic Scale (ISS). For the first time, palynological description of the Kryzhanivka climatolith correlated with the Calabriane of the ISS is presented for the studied section. Three subcomplexes are described in the composition of the Kryzhanivka complex. The characteristic features of the Kryzhanivka spore-pollen complex (SPC) and the changes in the ecological structure of each subcomplex are determined. Correlation of the established complex with the even-aged SPC of the Kryzhanivka deposits of the southern part of the Ukrainian Shield (the Eastern Azov Sea region). Outstanding questions of stratigraphic division of different facial deposits of the section based on palynological data are outlined. The necessity of further palynological studies of deposits of the section near Kryzhanivka village is substantiated.

Download Full-text

A COMPARATIVE ANALYSIS OF CHANGING SEDIMENTATION CONDITIONS DURING THE LAST INTERGLACIAL-GLACIAL MACROCYCLE IN THE LOESS AREAS OF THE SOUTHERN EAST EUROPEAN PLAIN (THE AZOV SEA REGION) AND CENTRAL CHINA (LOESS PLATEAU)

Geomorphology RAS ◽

10.15356/0435-4281-2017-1-3-18 ◽

2017 ◽

pp. 3-18 ◽

Cited By ~ 2

Author(s):

A. A. VELICHKO ◽

T. YANG ◽

A. O. ALEKSEEV ◽

O. K. BORISOVA ◽

P. I. KALININ ◽

...

Keyword(s):

Comparative Analysis ◽

Loess Plateau ◽

Central China ◽

East European Plain ◽

Last Interglacial ◽

East European ◽

Azov Sea ◽

Sedimentation Conditions

Download Full-text

The final stage of granitoid magmatism in the Dniester-Bug megablocks Ukrainian shield

Geochemistry and ore formation ◽

10.15407/gof.2016.36.072 ◽

2016 ◽

Vol 36 ◽

pp. 72-81 ◽

Cited By ~ 2

Author(s):

L.M. Stepaniuk ◽

◽

T.Y. Dovbush ◽

S.Y. Kurylo ◽

Y.M. Lesnaya ◽

...

Keyword(s):

Final Stage ◽

Ukrainian Shield ◽

Granitoid Magmatism

Download Full-text

Radioecology of Granite Deposits in the Western Part of the Srednepridneprovsky megablock of the Ukrainian Shield

Exploration and Environmental Geochemistry ◽

10.15407/geochem2017.01.003 ◽

2017 ◽

Vol 18 (1(18)) ◽

pp. 3-7

Author(s):

A.V. Plotnikov ◽

◽

V.V. Efimenko ◽

Keyword(s):

Ukrainian Shield

Download Full-text

New Findings of Rare Minerals in Alkaline Rocks of Ukrainian Shield

Mineralogical Journal ◽

10.15407/mineraljournal.42.04.003 ◽

2020 ◽

Vol 42 (4) ◽

pp. 3-22

Author(s):

V.V. SHARYGIN ◽

S.G. KRYVDIK ◽

O.V. DUBYNA

Keyword(s):

Rare Earth ◽

Chemical Composition ◽

Ukrainian Shield ◽

Silicate Mineral ◽

Alkaline Rocks ◽

First Finding ◽

Azov Region ◽

New Findings ◽

Oxide Minerals

Over recent years, new rare minerals have been discovered in the alkaline rocks of the Ukrainian Shield. Agpaitic varieties of alkaline magmatic and metasomatic rocks turned out to be especially abundant in rare minerals. Numerous findings are related to alkaline metasomatites which are considered to be fenites and apofenite albitites of the Dmytrivka quarry. It is well known primarily by the presence of various accessory (Nb, REE, and Zr) minerals, as well as silicate and oxide minerals that are rare for Ukraine. The most common albite microcline fenites of this quarry are characterized by rare-earth mineralization, whereas the concentration of REE decreases in apofenite albitites and Zr and Nb increase. New rare minerals were also found in the essentially albite rock with astrophyllite, alkaline pyroxene and amphibole of the Malatersa massif and agpaitic phonolites of the Oktyabrsky massif. In the rocks of the mentioned massifs and occurrences of alkaline rocks the most interesting are the findings of the perraultite — jinshajiangite series. They were found in three points of the Azov area and include 1) perraultite and jinshajiangite in the alkaline metasomatites of the Dmytrivka quarry; 2) only perraultite in agpaitic phonolites of the Oktyabrsky massif (Kam’yana gully); 3) jinshajiangite in a veined albite rock among the gabbro of the Malatersa massif. Baotite and minerals of the hejtmanite — bafertisite series were also found in the metasomatites of the Dmytrivka quarry. The latter belong to intermediate varieties in terms of MnO (10-17 wt.%) and FeO (10-17 wt.%) which distinguishes them from Fe-rich bafertisite from other regions. A silicate mineral with high content of Na, Zr, Mn and elevated Ti and Nb is rarely observed as small inclusions in the kupletskite grains from alkaline metasomatite of the Dmytrivka quarry. According to the chemical composition it was previously diagnosed as janhaugite. Tainiolite was found in some occurrences of alkaline metasomatites in the Azov region. In addition small aggregates of the REE-enriched epidote were found in fenites of the Kaplany village, which is probably the first finding in Ukraine. Two new Zr minerals have been found in the aegirine syenites of the Korsun-Novomyrhorod pluton: elpidite and mineral with a high content of Y2O3 (13-14 wt.%) (Y-hagatalite ?).

Download Full-text