scholarly journals Kaersutitis in Azov Area Rocks (Ukrainian Shield): Petrological Aspect

2021 ◽  
pp. 48-60
Author(s):  
V.O. Gatsenko ◽  
◽  
S.I. Kurylo ◽  

The paper presents the results of new studies of kaersutites from lamprophyres of the Pokrovo-Kyriivo massif (PKM) of the Azov area (Ukrainian Shield). The comparison of mineralogical-petrographic and chemical features of kaersutites of lamprophyres with those of other dyke (microgabroid) and plutonic (pyroxenite) rocks of PKM is carried out and also, with this mineral from the camptonites of the Khlibodar quarry and the pyroxenites of the Chomutov massif. The paper presents the results of new studies of kaersutites from lamprophyres of the Pokrovo-Kyriivo massif (PKM) of the Azov area (Ukrainian Shield). The comparison of mineralogical-petrographic and chemical features of kaersutites of lamprophyres with those of other dyke (microgabroid) and plutonic (pyroxenite) rocks of PKM is carried out and also, with this mineral from the camptonites of the Khlibodar quarry and the pyroxenites of the Chomutov massif. The crystal chemical characteristics of the studied kaersutites were compared with those of other amphiboles in the Azov area. According to the chemical composition of kaersutites, the conditions of kaersutite formation in the mafic rocks of the Azov area region were estimated. Microprobe studies of the chemical composition of kaersutites from kaersutite lamprophyres were performed on JXA- 8520F (JEOL) X-ray microanalyzer equipped with five wave dispersion spectrometers (WDS) at the Institute of Natural Sciences of the Slovak Academy of Sciences (Bysterka Branch). The main characteristics of the chemical composition of kaersutite from kaersutite lamprophyres of PKM are low content of TiO2 (0.5-0.68 f.o.) and Al2O3 (up to 11.4%). Due to the low Al2O3 content, they are similar to kaersutites from afir gabroid and pyroxenite PKM. Kaersutites from other rocks of the Azov area are characterized by a higher content of Al2O3 (more than 12.3%, more often — 13%). The sample of kaersutites from PKM lamprophyres is not homogeneous, which indicates fluctuations in the conditions of rock formation. Most of the studied kaersutites of the Azov area are characterized by #Mg higher than 0.55. The exception is the measured ferrokaersutite from Hlibodarivka camptonite megacrysts (# Mg = 0.43). The vast majority of Azov area kaersutites have a high alkali content (more than 3%). According to their crystal chemical characteristics, kaersutites of the Azov area region differ significantly from other amphiboles of the district. The most highly baric are ferrokaersutites from Hlibodarivka camptonite megacrysts and kaersutite from porphyry amphibole-titanomagnetite microgabrroid PKM. The formation of kaersutite from the mafiс rocks of the Azov area corresponds to the conditions of high oxygen fugacity. Ferrokaersutite from Hlibodarivka camptonite was formed under conditions of medium oxygen fugacity. Keywords: kaersutite, lamprophyre, mafic dyke, pyroxenites, the Pokrovo-Kyriivo massif, camptonites of the Khlibodar quarry, Azov area.

Author(s):  
C. Goessens ◽  
D. Schryvers ◽  
J. Van Landuyt ◽  
A. Verbeeck ◽  
R. De Keyzer

Silver halide grains (AgX, X=Cl,Br,I) are commonly recognized as important entities in photographic applications. Depending on the preparation specifications one can grow cubic, octahedral, tabular a.o. morphologies, each with its own physical and chemical characteristics. In the present study crystallographic defects introduced by the mixing of 5-20% iodide in a growing AgBr tabular grain are investigated. X-ray diffractometry reveals the existence of a homogeneous Ag(Br1-xIx) region, expected to be formed around the AgBr kernel. In fig. 1 a two-beam BF image, taken at T≈100 K to diminish radiation damage, of a triangular tabular grain is presented, clearly showing defect contrast fringes along four of the six directions; the remaining two sides show similar contrast under relevant diffraction conditions. The width of the central defect free region corresponds with the pure AgBr kernel grown before the mixing with I. The thickness of a given grain lies between 0.15 and 0.3 μm: as indicated in fig. 2 triangular (resp. hexagonal) grains exhibit an uneven (resp. even) number of twin interfaces (i.e., between + and - twin variants) parallel with the (111) surfaces. The thickness of the grains and the existence of the twin variants was confirmed from CTEM images of perpendicular cuts.


1974 ◽  
Vol 113 (6) ◽  
pp. 360 ◽  
Author(s):  
O.M. Sumbaev ◽  
E.V. Petrovich ◽  
Yu.P. Smirnov ◽  
I.M. Band ◽  
Aleksandr I. Smirnov

2020 ◽  
Vol 42 (4) ◽  
pp. 3-22
Author(s):  
V.V. SHARYGIN ◽  
S.G. KRYVDIK ◽  
O.V. DUBYNA

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 ?).


1987 ◽  
Vol 52 (1) ◽  
pp. 93-102 ◽  
Author(s):  
Jaroslav Vinš ◽  
Jan Šubrt ◽  
Vladimír Zapletal ◽  
František Hanousek

A method has been worked out for the reproducible preparation of Green Rust substances involving SO42-, Cl-, Br-, and I- anions. The chemical composition of the substances prepared has been followed in dependence on the synthesis conditions. The powder X-ray and electron diffraction patterns and infrared and Moessbauer spectra have been measured and discussed.


Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 807
Author(s):  
Ilya V. Kornyakov ◽  
Sergey V. Krivovichev

Single crystals of two novel shchurovskyite-related compounds, K2Cu[Cu3O]2(PO4)4 (1) and K2.35Cu0.825[Cu3O]2(PO4)4 (2), were synthesized by crystallization from gaseous phase and structurally characterized using single-crystal X-ray diffraction analysis. The crystal structures of both compounds are based upon similar Cu-based layers, formed by rods of the [O2Cu6] dimers of oxocentered (OCu4) tetrahedra. The topologies of the layers show both similarities and differences from the shchurovskyite-type layers. The layers are connected in different fashions via additional Cu atoms located in the interlayer, in contrast to shchurovskyite, where the layers are linked by Ca2+ cations. The structures of the shchurovskyite family are characterized using information-based structural complexity measures, which demonstrate that the crystal structure of 1 is the simplest one, whereas that of 2 is the most complex in the family.


Author(s):  
Radosław Rogoziński ◽  
Alina Maciejewska

AbstractVarved clay deposits from ice-dammed lakes are a particularly important and broadly applied raw material used for the production of high-quality ceramics (red bricks, roof tiles, etc.), but the mineralogy and geochemistry of these sediments are not fully understood. The aim of the present study was to determine the chemical and mineralogical composition of ice-dammed lake sediments of the Lębork deposit. Major-element analysis of the compositions of selected samples from the ice-dammed lake clays was performed by X-ray fluorescence (XRF) and trace elements were determined by inductively coupled plasma-mass spectrometry. The mineralogical composition of clay samples was determined by X-ray diffraction (XRD). Analyses of the chemical composition of the ice-dammed lake clays of the Lębork deposit showed that the dominant component was SiO2 with a mean content of 56.13 wt.%; the second most abundant component was Al2O3, with a mean content for the entire deposit of 11.61 wt.%. Analysis by ICP-MS indicated the presence of rare earth elements (REE), e.g. cerium, neodymium, lanthanum, and praseodymium; their mean contents are: 56.9, 27.0, 26.3, and 7.3 ppm, respectively. Mineralogical analysis of the varved clays identified quartz, muscovite, calcite, and clay minerals – illite, kaolinite, and montmorillonite. The material filling the Lębork basin is characterized by small lateral and vertical variability in chemical composition. The results of the present study may be of considerable importance in determining the parent igneous, metamorphic, and sedimentary rocks, the weathering products of which supplied material to the ice-dammed lake, as well as in determining the mechanisms and character of the sedimentation process itself.


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