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

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.

scholarly journals Geochemistry of Nb and Та in magmatic rocks of the Ukrainian Shield

2020 ◽  
Vol 41 ◽  
pp. 12-31
Author(s):  
S.G. Kryvdik ◽  
◽  
O.V Dubyna ◽  
◽  
Keyword(s):  
Igneous Rocks ◽  
Ukrainian Shield ◽  
Geochemical Data ◽  
Alkaline Rocks ◽  
Magmatic Rocks ◽  
Azov Sea ◽  
Continental Rifts ◽  
Alkaline Feldspar ◽  
High Concentrations ◽  
Almost All

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.

scholarly journals Prospects of the Tymoshivsko-Znamianskyi potential rare-metal ore area of Inhulskyi megablock of the Ukrainian Shield

2020 ◽  
pp. 3-12
Author(s):  
G. A. Kalashnyk
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Structural Control ◽  
Great Part ◽  
Rare Metal ◽  
Raw Material ◽  
Ukrainian Shield ◽  
Material Base ◽  
Hydrothermal Mineralization ◽  
Genetic Types

The article presents the results of the assessment of the prospects for discovery of industrial concentrations of rare and rare-earth elements in the Tymoshivsko-Znamianskyi potential rare-metal ore area of Inhulskyi megablock of the Ukrainian Shield. The results of studies of regularities of raremetalmineralization’s placement in Tymoshivsko-Znamianskyi potential ore region of the Inhulskyi megablock of the Ukrainian Shield are presented. The structural control of the great part of the detected geochemical anomalies, geochemical halos, manifestations and ore manifestations by certain systems of rupture faults and their intersection nodes is determined. The typical local features of manifestations of rare metal mineralization in small uranium deposits and large ore manifestations of this region and uranium mineralization of different genetic types, in particular hydrothermal mineralization of vein-stockwork type in mineralized fault zones are presented. According to the degree of manifestation of the complex of criteria, prospective ore and potentially ore nodes are discovered for possible detection of industrial concentrations of rare metals and rare-earth elements within the Tymoshivsko- Znamianskyi potential ore region, as well as uranium ores of various genetic types, in particular superimposed rich hydrothermal mineralization of vein-stockwork type. There were developed recommendations for further research in the Tymoshivsko-Znamianskyi potential ore region with the aim of farther development of rare and rare-earth elements raw material base.

scholarly journals 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)

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.

Cytomembrane Preservation in Tissue Dehydrated Only With Glutaraldehyde and Epon 812 Resin

1973 ◽  
Vol 31 ◽  
pp. 320-321
Author(s):  
Daniel C. Pease
Keyword(s):  
Diffraction Pattern ◽  
X Ray Diffraction ◽  
High Concentration ◽  
Unpublished Study ◽  
X Ray ◽  
Sectioned Material

A previous study demonstrated that tissue could be successfully infiltrated with 50% glutaraldehyde, and then subsequently polymerized with urea to create an embedment which retained cytomembrane lipids in sectioned material. As a result, the 180-190 Å periodicity characteristic of fresh, mammalian myelin was preserved in sections, as was a brilliant birefringence, and the capacity to bind OsO4 vapor in the hydrophobic bilayers. An associated (unpublished) study, carried out in co-operation with Drs. C.K. Akers and D.F. Parsons, demonstrated that the high concentration of glutaraldehyde (and urea) did not significantly alter the X-ray diffraction pattern of aldehyde-fixed, myelin. Thus, by itself, 50% glutaraldehyde has little effect upon cytomembrane systems and can be used with confidence for the first stages of dehydration.

Effects of carbamylcholine on chick embryo aggregate retina cell cultures

1988 ◽  
Vol 46 ◽  
pp. 350-351
Author(s):  
Glenn M. Cohen ◽  
Radharaman Ray
Keyword(s):  
Cell Cultures ◽  
Single Cells ◽  
Retinal Cell ◽  
Cell Aggregates ◽  
High Concentration ◽  
In Ovo ◽  
Sterile Culture ◽  
Retinal Tissue ◽  
Synaptic Junctions ◽  
And Control

Retinal,cell aggregates develop in culture in a pattern similar to the in ovo retina, forming neurites first and then synapses. In the present study, we continuously exposed chick retinal cell aggregates to a high concentration (1 mM) of carbamylcholine (carbachol), an acetylcholine (ACh) analog that resists hydrolysis by acetylcholinesterase (AChE). This situation is similar to organophosphorus anticholinesterase poisoning in which the ACh level is elevated at synaptic junctions due to inhibition of AChE, Our objective was to determine whether continuous carbachol exposure either damaged cholino- ceptive neurites, cell bodies, and synaptic elements of the aggregates or influenced (hastened or retarded) their development.The retinal tissue was isolated aseptically from 11 day embryonic White Leghorn chicks and then enzymatically (trypsin) and mechanically (trituration) dissociated into single cells. After washing the cells by repeated suspension and low (about 200 x G) centrifugation twice, aggregate cell cultures (about l0 cells/culture) were initiated in 1.5 ml medium (BME, GIBCO) in 35 mm sterile culture dishes and maintained as experimental (containing 10-3 M carbachol) and control specimens.

The Fine Structure of Phloem Cells

1985 ◽  
Vol 43 ◽  
pp. 632-635
Author(s):  
James Cronshaw
Keyword(s):  
Structural Studies ◽  
High Concentration ◽  
Long Distance ◽  
Phloem Tissue ◽  
Sieve Elements ◽  
Long Distance Transport ◽  
P Protein ◽  
Companion Cells ◽  
Electron Microscopical ◽  
Distance Transport

Long distance transport in plants takes place in phloem tissue which has characteristic cells, the sieve elements. At maturity these cells have sieve areas in their end walls with specialized perforations. They are associated with companion cells, parenchyma cells, and in some species, with transfer cells. The protoplast of the functioning sieve element contains a high concentration of sugar, and consequently a high hydrostatic pressure, which makes it extremely difficult to fix mature sieve elements for electron microscopical observation without the formation of surge artifacts. Despite many structural studies which have attempted to prevent surge artifacts, several features of mature sieve elements, such as the distribution of P-protein and the nature of the contents of the sieve area pores, remain controversial.

Tem analysis of multiple-energy arsenic implanted and Rta'd silicon

1987 ◽  
Vol 45 ◽  
pp. 246-247
Author(s):  
R.A. Herring
Keyword(s):  
Device Fabrication ◽  
High Concentration ◽  
Tem Analysis ◽  
Defect Clusters ◽  
High Fluences ◽  
Small Defect ◽  
Before And After ◽  
The Matrix ◽  
The Difference ◽  
Factor Type

Rapid thermal annealing (RTA) of ion-implanted Si is important for device fabrication. The defect structures of 2.5, 4.0, and 6.0 MeV As-implanted silicon irradiated to fluences of 2E14, 4E14, and 6E14, respectively, have been analyzed by electron diffraction both before and after RTA at 1100°C for 10 seconds. At such high fluences and energies the implanted As ions change the Si from crystalline to amorphous. Three distinct amorphous regions emerge due to the three implantation energies used (Fig. 1). The amorphous regions are separated from each other by crystalline Si (marked L1, L2, and L3 in Fig. 1) which contains a high concentration of small defect clusters. The small defect clusters were similar to what had been determined earlier as being amorphous zones since their contrast was principally of the structure-factor type that arises due to the difference in extinction distance between the matrix and damage regions.

Scanned tip measurement of deep vertical facets on a flat surface: Measuring roughness on gaas laser waveguide mirrors

1993 ◽  
Vol 51 ◽  
pp. 532-533
Author(s):  
Chang Shen ◽  
Phil Fraundorf ◽  
Robert W. Harrick
Keyword(s):  
Integrated Circuits ◽  
Flat Surface ◽  
Scanning Force Microscopy ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Force Microscopy ◽  
Optoelectronic Integrated Circuits ◽  
Laser Waveguide ◽  
Scanning Force ◽  
Gaas Laser

Monolithic integration of optoelectronic integrated circuits (OEIC) requires high quantity etched laser facets which prevent the developing of more-highly-integrated OEIC's. The causes of facet roughness are not well understood, and improvement of facet quality is hampered by the difficulty in measuring the surface roughness. There are several approaches to examining facet roughness qualitatively, such as scanning force microscopy (SFM), scanning tunneling microscopy (STM) and scanning electron microscopy (SEM). The challenge here is to allow more straightforward monitoring of deep vertical etched facets, without the need to cleave out test samples. In this presentation, we show air based STM and SFM images of vertical dry-etched laser facets, and discuss the image acquisition and roughness measurement processes. Our technique does not require precision cleaving. We use a traditional tip instead of the T shape tip used elsewhere to preventing “shower curtain” profiling of the sidewall. We tilt the sample about 30 to 50 degrees to avoid the curtain effect.

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