scholarly journals Peculiarities of the composition of the high-titanium ultramafite dyke in the Andriivka open pit (the Eastern Azov area of the Ukrainian shield)

2019 ◽  
Vol 40 ◽  
pp. 40-47 ◽  
Author(s):  
V.O. Gatsenko ◽  
◽  
S.G. Kryvdik ◽  
S.V. Kushnir ◽  
◽  
...  
Keyword(s):  
Ukrainian Shield ◽  
Open Pit

scholarly journals AGE SPAN FORMATION IN GRANITOIDS OF UKRAINIAN SHIELD

2020 ◽  
pp. 12-16
Author(s):  
L. Stepanyuk ◽  
О. Hrinchenko ◽  
T. Dovbush ◽  
O. Ziultsle ◽  
N. Konoval ◽  
...  
Keyword(s):  
Ukrainian Shield ◽  
Open Pit ◽  
Isotopic Dating ◽  
Potassic Feldspar ◽  
Genetic Nature ◽  
Southwestern Area ◽  
Dating Method ◽  
Magmatic Replacement ◽  
Granitic Melt

The paper discusses Berdychiv type granitoids that have always stirred up interest among researchers of the Ukrainian Shield. These rocks include minerals that are uncharacteristic of granites - cordierite, sillimanite, andalusite - and are closely related to rocks of the supposed substratum. At the same time, there still remain questions about the genetic nature of Berdychiv granites. Despite the fact that most researchers treat these granites as intrusive (anatectic) formations, there are other concepts according to which these granites are considered to be the products of metasomatic transformation (magmatic replacement) of primarily argillaceous and marly series of substratum. The Stryzhavka open pit, which is located in the Upper Bug region of the Ukrainian Shield displays differently cataclised porphyry-like plagiogranitoids (predominantly, garnet-bearing varieties in its southwestern area, locally rock-forming potassic feldspar varieties), and garnet-bearing leucocratic granites similar to those of Berdychiv type granites. The monazites of biotite-garnet granodiorite and biotite-garnet granite were dated by uranium-lead (U-Pb) isotopic dating method. The monazite of granodioritеs is dated 2049,3±3,5 million years based on the upper intersection of concordia with discordia. Significantly lower values of age (about 15 million years younger) for the monazite selected from granite, approximating 2035,1±1,9 million years were established. We assume it to be caused by prolonged crystallization of granitic melt and rather early crystallization of more basiс granodioritic magma in comparison with granitic one. Thus, the duration of the granitoid formation uncovered in the Stryzhavka open pit exceeds 15 million years, which correlates accurately with the estimates for occurrence duration of the granitic melts, which gave rise to various granites of the Ukrainian Shield.

scholarly journals Kaersutite lamprophyres of the Pokrovo-Kyriivo massif (the Azov area, Ukraine): petrographic features, mineral composition, geochemistry

2020 ◽  
Vol 41 ◽  
pp. 42-53
Author(s):  
V.O. Gatsenko ◽  
◽  
S.V. Kushnir ◽  
Keyword(s):  
Mineral Composition ◽  
Microprobe Analysis ◽  
Electron Microprobe Analysis ◽  
Mafic Rock ◽  
Ukrainian Shield ◽  
Open Pit ◽  
Tio2 Content ◽  
Fine Grained ◽  
Bottom Hole ◽  
Folded Structure

The paper represents results of the petrographical, geochemical and mineralogical studies of a dyke of porphyry-like mafic rock from the Pokrovo-Kyriivo massif of the Azov area, the Ukrainian Shield. This dyke of fine-grained rock has unique mineral composition as the main mineral in the groundmass is kaersutite. According to mineralogical and petrographic features, it can be identified as kaersutite lamprophyre. The Devonian Pokrovo-Kyriivo massif is located at a junction of the Azov Domain of the Ukrainian Shield and the folded structure of Donbas. This massif is composed of subalkaline (pyroxenite, gabbro) and alkaline (malignites, nepheline syenite) rocks which are cut by numerous dykes varying in composition from ultramafic to intermediate. The dyke of finegrained kaersutite lamprophyre was discovered in the bottom hole of the drillhole 36, where it is intruded into mediumgrained gabbroids and pyroxenites. The groundmass of the rock is composed of kaersutite, titanomagnetite, albite, chlorite, titanite, pyrite, chalcopyrite, apatite, monazite. The phenocrysts are represented by chlorite and talc pseudomorphoses after a diamond-shaped mineral with shortened obtuse angles. According to electron microprobe analysis, kaersutite has low TiO2 content and intermediate mg# values of 0.54—0.67. According to the chemical composition, studied kaersutites differ from the same mineral in the microgabro dyke in the Pokrovo-Kyriivo massif, and from kaersutites in camptonites of the Khlibodarivka open pit in the Azov area. At the same time, it is similar to kaersutites from camptonites of the Novoukrainka dyke field of the Inhul terrane. Kaersutite lamprophyre also differ from dyke rocks of the Pokrovo-Kyriivo massif by the absence of clinopyroxene, mica, ilmenite and low content of TiO2 in titanomagnetite, which does not exceed 6 %. This is due to a low TiO2 content in the rocks (up to 3.5 %), relative to other dyke gabbro of the area. According to mineralogical-petrographic and chemical characteristics, kaersutite lamprophyres are unique rocks that have no direct counterparts in the Azov area or on the Ukrainian Shield in the whole.

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

2016 ◽  
Vol 36 ◽  
pp. 72-81 ◽  
Author(s):  
L.M. Stepaniuk ◽  
◽  
T.Y. Dovbush ◽  
S.Y. Kurylo ◽  
Y.M. Lesnaya ◽  
...  
Keyword(s):  
Final Stage ◽  
Ukrainian Shield ◽  
Granitoid Magmatism

New Findings of Rare Minerals in Alkaline Rocks of Ukrainian Shield

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 ?).

Scarn Gold Mineralization of the Bandurka Ore Occurrences (Ingul Megablock, Ukrainian Shield)

2017 ◽  
Vol 39 (2) ◽  
pp. 8-18
Author(s):  
N. Lyzhachenkо ◽  
◽  
S. Bondarenko ◽  
S. Kurylо ◽  
V. Syоmkа ◽  
...  
Keyword(s):  
Gold Mineralization ◽  
Ukrainian Shield
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