scholarly journals PETROGRAFIE A MINERALOGIE KRUPNÍKOVÉHO TĚLESA NA LOKALITĚ ZADNÍ HUTISKO U VERNÍŘOVIC (HRUBÝ JESENÍK)

2018 ◽  
Vol 25 (1-2) ◽  
Author(s):  
Jiří Zimák ◽  
Zuzana Juránková
Keyword(s):  
Bohemian Massif ◽  
The Body ◽  
Metasomatic Alteration ◽  
Accessory Minerals ◽  
Ore Minerals ◽  
Variable Content ◽  
Chlorite Schist ◽  
Magnetite Formation

The paper deals with mineralogy and petrology of a soapstone body at the locality Zadní Hutisko near Vernířovice in the Hrubý Jeseník Mts. (NE part of the Bohemian Massif). The soapstone body is located in the northern spur of the Sobotín Massif composed dominately of amphibolites. The soapstone body shows a very distinct symmetrical internal zonation. Four main types of rocks can be distinguished in the direction from the centre to the edge of the body: i) soapstone (talc + dolomite); ii) talc schist; iii) tremolite schist; iv) chlorite schist. Common accessory minerals of the rocks are apatite and magnetite. Formation of the studied soapstone body may have been caused by metasomatic alteration of peridotite (serpentinite). Epidote-chlorite granofels with a variable content of amphibole (magnesiohornblende or tschermakite) and with a high content of opaque ore minerals (magnetite, hematite, and also ilmenite) was found at the contact of the soapstone body with amphibolite. Epidote-chlorite granofels has been formed by alteration of amphibolite.

scholarly journals Mineralogie krupníkového tělesa v Medvědím dole u Koutů nad Desnou v Jeseníkách

2017 ◽  
Vol 24 (1-2) ◽  
Author(s):  
Jiří Zimák ◽  
Bohuslav Fojt ◽  
Zuzana Juránková
Keyword(s):  
Hydrothermal Alteration ◽  
Bohemian Massif ◽  
Shear Zones ◽  
Accessory Mineral ◽  
Mineral Association ◽  
Body Formation ◽  
Variable Content ◽  
Chlorite Schist

Soapstone bodies are relatively common in the Sobotín Massif in the Hrubý Jeseník Mts. (NE part of the Bohemian Massif). There was a small soapstone body found near Kouty nad Desnou in the northern spur of the Sobotín Massif composed dominately of amphibolites. The article focuses on mineralogy and petrology of this body and rocks in its surroundings (mainly hornblendite). Studied soapstone body is composed of these four types of rocks: i) talc schists with variable content of chlorite (clinochlore) and amphibole (actinolite, magnesiohornblende); ii) soapstone (mineral association talc + dolomite); iii) chlorite schist; iv) actinolite schist. Chromite is a typical accessory mineral of soapstone body rocks as well as hornblendite. This soapstone body does not show mineralogical and petrographical zonality typical for well-known soapstone bodies of the Sobotín Massif – former soapstone deposits Smrčina and Zadní Hutisko. However there is no mineralogical or petrographical difference between those deposits and studied soapstone body. Formation of the soapstone body at Kouty nad Desnou is probably connected to hydrothermal alteration of hornblendite running along shear zones.

scholarly journals Magmatic and Postmagmatic Mineral Associations of the Malyutka Massif Rocks (Khudolazovkiy Complex of the South Urals)

2021 ◽  
Vol 20 (2) ◽  
pp. 99-109
Author(s):  
I.R. Rakhimov ◽  
Keyword(s):  
Chemical Composition ◽  
Crystallization Temperature ◽  
Equilibrium Temperature ◽  
South Urals ◽  
The South ◽  
Accessory Minerals ◽  
Rock Formation ◽  
Genetic Interpretation ◽  
Mineral Associations ◽  
Ore Minerals

The results of detailed mineralogical studies of the Malyutka massif altered rocks of the Khudolazovskiy differentiated complex are presented. The morphology and chemical composition of many rock-forming and accessory minerals are described. According to the study, the magmatic and post-magmatic (hydrothermal-metasomatic) stages of rock formation are distinguished. The problems associated with the genetic interpretation of a number of rock-forming and ore minerals are discussed. The conclusion about the polygenic nature of the formation of spinelids is made. The equilibrium temperature in the «Ti-magnetite–ilmenite» system (633–650 °C), as well as the crystallization temperature of chlorite, replacing phlogopite and hornblende (145–185 °C), were estimated.

scholarly journals Rare-earth accessories and secondary minerals in plagiogneisses from the Stankuvatske Li-deposite

2020 ◽  
Vol 41 ◽  
pp. 54-67
Author(s):  
N.М. Lyzhachenkо ◽  
◽  
S.I. Kurylo ◽  
S. M. Bondarenko ◽  
◽  
...  
Keyword(s):  
Rare Earth ◽  
Microprobe Analysis ◽  
Metamorphic Rocks ◽  
Metasomatic Alteration ◽  
Accessory Minerals ◽  
Secondary Minerals ◽  
Fine Grained ◽  
Partial Redistribution ◽  
Bulk Chemical ◽  
First Time

The Stankuvatske Li deposit (SD) is situated at western flank of the Lypniazka structure (Ingul megablock of the Ukrainian Shield). Knowledge about REE content in host metamorphic rocks is based on the results of bulk chemical analysis, but their minerals have not been determined. For the first time rare-earth mineralization of the Stankuvatsky lithium deposit has been investigated in fine-grained gneiss with «augen» and schistose structure, porphiroblastic texture, formed as result of tectonical alteration. Our investigations were carried out using petrographic and microprobe analysis (EPMA). Mineralogically gneisses consist of quartz, plagioclase, zoizite, biotite, graphite, chlorite and abundant sulphides mainly represented by pyrite, arsenopyrite, sphalerite, molibdenite. Accessory minerals presented by titanite, apatite, monazite, zircon and coffinite. Gneisses have been subjected to deformation and hydrothermal — metasomatic alteration. An investigation of rock-forming and accessory minerals allows to revel low-temperature alterations of primary allanite by bastnäsiteand chlorite with formation of secondary bastnäsite-chlorite-coisite-pyrite association with «coronary» texture. The penetration of S, F, CO2, H2O enriched fluids were caused disintegration, partial redistribution and reprecipitation of rare earth elements. As result synhysite-chlorite-pyrite association was formed.

Mineralogická charakteristika hydrotermální mineralizace ze starých těžebních pozůstatků v oblasti Mladoňov - Nový Malín (silezikum)

2020 ◽  
Vol 28 (2) ◽  
pp. 261-275
Author(s):  
Zdeněk Dolníček ◽  
Miroslav Nepejchal ◽  
Vlastimil Flášar ◽  
Jana Ulmanová
Keyword(s):  
Electron Microprobe ◽  
Bohemian Massif ◽  
Native Gold ◽  
Native Copper ◽  
Ore Minerals ◽  
Ore Mineralization ◽  
Area North ◽  
Native Bismuth

In the area north of Mladoňov, which is built by phyllites and quartzites of the Vrbno Group and granite-derived phyllonites of the Desná Group (Silesicum, northern part of the Bohemian Massif), there were found two types of hydrothermal ore mineralization in vein material sampled from remnants of old mining/prospection. The Cu(-Bi-Au) mineralization hosted by quartz gangue was found at the locality Husarčina šachta. A main ore mineral is chalcopyrite, which contains inclusions of pyrite, native bismuth, bismuthinite, a phase close to bismite, and native gold with fineness of 717 - 818. Baryte, recorded in part of collected samples, probably represents a significantly younger hypogene mineralization. Supergene minerals include malachite, azurite, a phase close to chrysocolla, bornite, Cu-sulphides, tenorite, native copper, limonite and probably also cuprite. A quartz-pyrite-pyrrhotite mineralization with accessory arsenopyrite and xenotime-(Y) and supergene limonite and baryte was recorded at localities Husarčina šachta and Kopka. Sporadically, Fe-sulphides contain elevated contents of Au (measurable by means of an electron microprobe), probably due to submicroscopic inclusions of native gold. Gold could be leached from wall rocks by ore fluids and/or remobilized from older mineralization to the younger one. The presence of traces of Cr, Co and Ni in some ore minerals implies for wider circulation of parent fluids involving probably also basic or ultrabasic rocks.

Gold and silver accessory minerals in ultramafites of the Kyzyr-Burlyuksky ultramafic massif (Western Sayan)

2022 ◽  
pp. 109-120
Author(s):  
Alexey Yurichev
Keyword(s):  
Low Temperature ◽  
Ultramafic Rocks ◽  
Natural Setting ◽  
Accessory Minerals ◽  
Ultramafic Massif ◽  
Ore Minerals ◽  
Native Silver ◽  
Temperature Transformation ◽  
Western Sayan ◽  
Epigenetic Processes

The study focuses on gold and silver accessory minerals (native silver, cuprous gold, luanheite (Ag3Hg), unspecified mineral phase (Cu,Ag,Hg), first diagnosed in dunites and apodunite serpentinites of the Kyzyr-Burlyuksky ultramafic massif, which is part of the Kurtushibin ophiolite belt of Western Sayan. The revealed ore minerals are mainly observed in the form of single hypidiomorphic, irregular microscopic precipitates (0.5– 3.0 μm) mainly inside magnetite, much less often in grains of avaruite. Typomorphic and chemical features of ore minerals, their natural setting in rock-forming silicate matrix are characterized. Formation and concentration of these accessory minerals is associated with superimposed low-temperature transformation (hydration) processes affecting original ultramafic rocks. At the same time, the presence of luanheite and an unnamed phase (Cu,Ag,Hg), along with the previously identified potarite (PdHg), is probably evidence of low-temperature conditions of mineral formation during the manifestation of epigenetic processes of serpentinization (lowgrade metamorphism) due to solutions enriched in mercury. The source of such solutions could be gabbro intrusions that penetrated later into the main ultramafic body.

scholarly journals Minerály kontaminovaných granitových pegmatitů z lomu Pohled u Havlíčkova Brodu (moldanubikum), část I: oxidy, karbonáty, silikáty a fosfáty

2020 ◽  
Vol 28 (1) ◽  
pp. 132-151 ◽  
Author(s):  
Zdeněk Dolníček ◽  
Karel Malý ◽  
Jana Ulmanová ◽  
Jaroslav Havlíček ◽  
Luboš Vrtiška
Keyword(s):  
Czech Republic ◽  
Mineral Composition ◽  
Bohemian Massif ◽  
Small Body ◽  
Coarse Grained ◽  
Metamorphic Rocks ◽  
Granitic Pegmatites ◽  
Ore Minerals ◽  
Magmatic Stage

In the Pohled quarry near Havlíčkův Brod town (central part of Czech Republic), granitic pegmatites form dikes or irregular bodies cementing breccia of host metamorphic rocks (paragneisses, amphibolites) belonging to the Monotonous (Ostrong) Group of the Moldanubicum of the Bohemian Massif. Pegmatites exhibit coarse-grained textures and very simple mineral composition, which, however, was in places strongly modified by superimposed hydrothermal alterations and locally also by crystallization of ore minerals. K-feldspar, plagioclase (An0-38), biotite (phlogopite), apatite (fluorapatite to hydroxylapatite), zircon, allanite-(Ce) and part of quartz undoubtedly originated during magmatic stage. Products of hydrothermal alterations include younger quartz, Fe-Mg chlorites (older clinochlore and younger chamosite with an admixture of Ca-smectite), prehnite, clinozoisite, amphibole (actinolite), titanite, calcite, and very probably also ilmenite (with up to 22.5 mol. % of pyrophanite), rutile, anatase and V-Cr-Fe-rich grossular with 13 - 25 mol.% of goldmanite and 12 - 24 mol.% uvarovite. The elevated contents of Mg, Ca, V and Cr found in some minerals are associated with a material contamination by the surrounding metamorphic rocks (especially amphibolites, serpentinites and perhaps also graphitic lithologies), which took place with varying intensity during both magmatic and hydrothermal stages of evolution of the studied pegmatites. Geochemically, they are poorly fractionated pegmatites, whose origin was probably connected with anatexis of the host Moldanubian metamorphic rocks, which was likely associated with emplacement of adjacent small body of the Pohled Granodiorite.

Representing utility and deploying the body

2020 ◽  
Vol 43 ◽  
Author(s):  
David Spurrett
Keyword(s):  
Functional Activity ◽  
Degrees Of Freedom ◽  
The Body ◽  
Target Article ◽  
Processing Demands ◽  
The Many

Abstract Comprehensive accounts of resource-rational attempts to maximise utility shouldn't ignore the demands of constructing utility representations. This can be onerous when, as in humans, there are many rewarding modalities. Another thing best not ignored is the processing demands of making functional activity out of the many degrees of freedom of a body. The target article is almost silent on both.

Neuron-glia relationship during the early postembryonic development of the nervous system in some oligochaetes

1978 ◽  
Vol 36 (2) ◽  
pp. 600-601
Author(s):  
Wiktor Djaczenko ◽  
Carmen Calenda Cimmino
Keyword(s):  
Nervous System ◽  
Glial Cells ◽  
Early Period ◽  
Postembryonic Development ◽  
Ruthenium Red ◽  
The Body ◽  
Tubifex Tubifex ◽  
Growth Stages ◽  
Cell Processes ◽  
Cytoplasmic Processes

The simplicity of the developing nervous system of oligochaetes makes of it an excellent model for the study of the relationships between glia and neurons. In the present communication we describe the relationships between glia and neurons in the early periods of post-embryonic development in some species of oligochaetes.Tubifex tubifex (Mull. ) and Octolasium complanatum (Dugès) specimens starting from 0. 3 mm of body length were collected from laboratory cultures divided into three groups each group fixed separately by one of the following methods: (a) 4% glutaraldehyde and 1% acrolein fixation followed by osmium tetroxide, (b) TAPO technique, (c) ruthenium red method.Our observations concern the early period of the postembryonic development of the nervous system in oligochaetes. During this period neurons occupy fixed positions in the body the only observable change being the increase in volume of their perikaryons. Perikaryons of glial cells were located at some distance from neurons. Long cytoplasmic processes of glial cells tended to approach the neurons. The superimposed contours of glial cell processes designed from electron micrographs, taken at the same magnification, typical for five successive growth stages of the nervous system of Octolasium complanatum are shown in Fig. 1. Neuron is designed symbolically to facilitate the understanding of the kinetics of the growth process.

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