scholarly journals VNITŘNÍ ZONÁLNOST TĚLES HORNIN TĚŠÍNITOVÉ ASOCIACE VE SLEZSKÉ JEDNOTCE: KORELACE PETROGRAFICKÝCH A PETROFYZIKÁLNÍCH PARAMETRŮ

2014 ◽  
Vol 21 (1-2) ◽  
Author(s):  
Kristýna Schuchová ◽  
Zdeněk Dolníček
Keyword(s):  
Magnetic Susceptibility ◽  
Igneous Rocks ◽  
Western Carpathians ◽  
Published Data ◽  
Modal Composition ◽  
Petrophysical Parameters ◽  
Rock Samples ◽  
Outer Western Carpathians ◽  
Petrographic Study

This article is focused on petrography of igneous rocks of the teschenite association and its correlation with selected petrophysical parameters. These igneous rocks were studied at three localities in the Silesian unit (Outer Western Carpathians) – Hodslavice, Žilina near Nový Jičín and Tichá. We conducted petrographic study (including modal composition based on planimetry) and then we compared results with previously published data on magnetic susceptibility and density of the same rock samples. The primary magmatic phases (clinopyroxenes, amphibole, biotite, opaque phases, feldspars and analcime) show in all cases less or more signs of post-magmatic alteration, giving rise mainly to secondary chlorite, carbonate and “limonite”. The amount of chlorite ranges from 21 to 23, 3 to 9, and 16 to 35 mod. % and those of carbonate vary from 5 to 15, 3 to 4, and 16 to 24 mod. % in Hodslavice, Žilina near Nový Jičín, and Tichá, respectively. The values of magnetic susceptibility range from 5.56 × 10-8 to 7.66 × 10-5, 5.07 × 10-7 to 1.61 × 10-5, and 2.46 × 10-7 to 2.93 × 10-5 SI and those of density are between 2.50 and 2.77, 2.66 to 3.88, and 2.65 to 2.86 g/cm3 in Hodslavice, Žilina near Nový Jičín, and Tichá, respectively. Correlation of petrographic and petrophysical parameters suggests that various postmagmatic alterations (including chloritization, carbonatization and weathering associated with formation of limonite) can influence the values of magnetic susceptibility and density. The intensity of these alterations varies significantly among samples and sites.

scholarly journals Vliv diagenetických procesů na asociaci těžkých minerálů v pískovcích z lokality Slivotín (ždánická jednotka, flyšové pásmo Vnějších Západních Karpat, Česká republika)

2021 ◽  
Vol 29 (1) ◽  
pp. 27-40
Author(s):  
Zdeněk Dolníček ◽  
Michaela Krejčí Kotlánová ◽  
Rostislav Koutňák
Keyword(s):  
Chemical Composition ◽  
Volcanic Rocks ◽  
Primary Source ◽  
Heavy Mineral ◽  
Heavy Minerals ◽  
Western Carpathians ◽  
Chrome Spinel ◽  
Published Data ◽  
Diagenetic Alteration ◽  
Outer Western Carpathians

An electron microprobe study of polished sections prepared from a sample of fine-grained sandstone from the locality Slivotín (Ždánice-Hustopeče Formation, Ždánice Unit, Flysch Belt of the Outer Western Carpathians, Czech Republic) allowed to yield in addition to data on chemical composition also the detailed information on in situ textural relationships of individual minerals. During our study, emphasis was given to accessory phases belonging to the translucent heavy mineral fraction. The detrital garnet (Alm36-82Grs2-45Prp2-22Sps0-15) was extensively dissolved and replaced by calcite cement from its margins and along the cracks. Detrital fluorapatite was dissolved in a similar way, however, dissolution episode was followed by growth of authigenic rims composed of carbonate-fluorapatite. Other observed heavy minerals (zircon, chrome spinel, TiO2 phase, monazite, tourmaline) probably remained unaltered by diagenetic processes. The chemical composition of chrome spinels varies mostly between magnesiochromite and chromite, whereas spinel is very rare. The chemical composition of garnets and chrome spinels is comparable with published data from Czech, Polish and Slovak parts of the Flysch Belt of the Western Carpathians, and indicates the primary source of detrital material in rocks of deeper parts of orogen, characterized especially by the presence of catazonal metamorphites and almost lacking volcanic rocks. Redeposition of heavy minerals from older sediments cannot also be ruled out. The pronounced diagenetic alteration of garnet, if not very scarce in the area of Flysch Belt, could help to explain the earlier observations of wide fluctuations of contents of garnet in heavy mineral concentrates.

Anisotropy of magnetic susceptibility as an indicator for palaeocurrent analysis in folded turbidites (Outer Western Carpathians, Poland)

Sedimentology ◽  
2020 ◽  
Vol 67 (7) ◽  
pp. 3783-3808
Author(s):  
Aleksandra Stachowska ◽  
Maciej Łoziński ◽  
Michał Śmigielski ◽  
Anna Wysocka ◽  
Leszek Jankowski ◽  
...  
Keyword(s):  
Magnetic Susceptibility ◽  
Anisotropy Of Magnetic Susceptibility ◽  
Western Carpathians ◽  
Outer Western Carpathians

scholarly journals Measurement of Magnetic Susceptibility on Some Rock Samples in Parts of Kuje Area, Abuja-Nigeria

2019 ◽  
Vol 1 ◽  
pp. 275-280
Author(s):  
N N Abdulsalam ◽  
O Ologe
Keyword(s):  
Magnetic Susceptibility ◽  
Metamorphic Rock ◽  
Sedimentary Rocks ◽  
Magnetic Anomalies ◽  
Igneous Rocks ◽  
Rock Samples ◽  
Minimum Value ◽  
Maximum Value ◽  
Sedimentary Succession

Magnetic Susceptibility values are important in interpreting regional magnetic anomalies and in crustal modeling. In this study, Magnetic Susceptibility has been measured on rock samples from the sedimentary succession of Kuje Area in FCT. Variation of susceptibility for the different samples has been analyzed and confirm in the study. According to the measured susceptibility values based on the selected samples, the minimum susceptibility value for sedimentary rocks was found to be 0 which was the minimum value obtained for Dolomite and the maximum susceptibility value for sedimentary rocks was found to be 1480cgs which was the maximum value obtained for shales. For metamorphic rock, the minimum susceptibility value was found to be 25cgs which was the minimum value obtained for schists and its maximum susceptibility value was found to be 3,000cgs which was the maximum value obtained for slate. Finally, the minimum susceptibility value for igneous rocks was found to be 20cgs which was the minimum value obtained for rhyolite and its maximum susceptibility value was 14500cgs which was the maximum value obtained for basalts

scholarly journals The Upper Cretaceous Ostravice Sandstone in the Polish sector of the Silesian Nappe, Outer Western Carpathians

2016 ◽  
Vol 67 (2) ◽  
pp. 149-166 ◽  
Author(s):  
Marek Cieszkowski ◽  
Anna Waśkowska ◽  
Justyna Kowal-Kasprzyk ◽  
Jan Golonka ◽  
Tadeusz Słomka ◽  
...  
Keyword(s):  
Czech Republic ◽  
Upper Cretaceous ◽  
Western Carpathians ◽  
The Czech Republic ◽  
Lithostratigraphic Unit ◽  
Outer Western Carpathians ◽  
Outer Carpathians ◽  
Lowermost Part

Abstract The Ostravice Sandstone Member was identified and described as a lithostratigraphic unit in the Polish part of the Outer Carpathians. This division occurs in the lowermost part of the Godula Formation, is underlain by variegated deposits of the Mazák Formation or directly by the Barnasiówka and Lhoty formations, and overlain by the Czernichów Member of the Godula Formation. Domination by thick- and very thick-bedded sandstones, conglomeratic sandstones and conglomerates rich in calcareous clasts, mostly of the Štramberk-type limestones, is typical for the Ostravice Sandstone Member. These deposits are widespread between the Moravskoslezské Beskydy Mountains in the Czech Republic and the Ciężkowice Foothills in Poland. The documentation of the Ostravice Sandstone Member occurrence as well as the petrological, sedimentological features, and inventory of the carbonate clasts are presented here.

scholarly journals Uran, thorium a draslík v krystaliniku a paleozoických sedimentech na mapovém listu 14-33 Polička – laboratorní gamaspektrometrie a parciální chemické složení variských plutonitů

2017 ◽  
Vol 24 (1-2) ◽  
Author(s):  
Jiří Zimák
Keyword(s):  
Natural Radioactivity ◽  
Gamma Ray ◽  
Igneous Rocks ◽  
Crystalline Complex ◽  
Rock Samples ◽  
Gamma Ray Spectrometer ◽  
Variscan Granitoids ◽  
Mass Activity ◽  
Geological Units

The paper deals with natural radioactivity of metamorphic and igneous rocks and Palaeozoic sediments within the map sheet 14-33 Polička. Studied rocks belong to three geological units: the Hlinsko Zone (phyllites and quartzites of the Mrákotín Fm., flysch sediments of the Hlinsko-Rychmburk Fm.), the Svratka Crystalline Complex (mainly mica schists, paragneisses, orthogneisses and migmatites, also amphibolites, skarns, erlans and quartzites) and the Polička Crystalline Complex (mica schists, paragneisses to migmatites and the Variscan granitoids are dominant). Concentrations of potassium, uranium and thorium were measured using a laboratory gamma-ray spectrometer in 805 rock samples. Data are tabled and discussed. Natural radioactivity of rocks is evaluated on the basis of the calculated values of mass activity of 226Ra equivalent (am). Slightly increased am values were found in migmatites and orthogneisses of the Svratka Crystalline Complex (187 Bq.kg-1 on average), granites and granodiorites of the Budislav Pluton (216 Bq.kg-1), granodiorites and rocks of a tonalite suite of the Miřetín Pluton (199 and 194 Bq.kg-1). Increased concentrations of uranium and thorium were found in some samples of pegmatite and aplite. Radioactivity of rocks of the Hlinsko-Rychmburk and Mrákotín Fms. can be assessed as relatively low.

scholarly journals Nannofossil record across the Cenomanian-Coniacian interval in the Bohemian Cretaceous Basin and Tethyan foreland basins (Outer Western Carpathians), Czech Republic

2012 ◽  
Vol 63 (3) ◽  
pp. 201-217 ◽  
Author(s):  
Lilian Švábenická
Keyword(s):  
Czech Republic ◽  
Black Shales ◽  
Western Carpathians ◽  
High Latitudes ◽  
Foreland Basins ◽  
Mutual Correlation ◽  
The Czech Republic ◽  
Outer Western Carpathians ◽  
First Occurrence ◽  
Bohemian Cretaceous Basin

Nannofossil record across the Cenomanian-Coniacian interval in the Bohemian Cretaceous Basin and Tethyan foreland basins (Outer Western Carpathians), Czech Republic Nannofossil biostratigraphy and mutual correlation was worked out for the Cenomanian-Coniacian deposits of the Bohemian Cretaceous Basin (BCB) and Outer Western Carpathians (OWC) in the territory of the Czech Republic. Similar assemblages of the BCB and from sediments deposited on the SE slopes of West European Platform, Waschbergždánice-Subsilesian Unit, OWC support the hypothesis that the two areas were connected by a sea way (nowadays the Blansko trough). The nannoflora of the Silesian Unit, OWC show more afinity to high latitudes as is documented by the presence of Marthasterites furcatus in the Lower Turonian, UC6b and UC7 Zones. Turonian and Coniacian deep-water flysch sediments of the Silesian Unit and Magura Group of Nappes provide nannofossils on rare occassions. Strongly atched nannofossils dominated by W. barnesiae from Cenomanian black shales of the BCB are comparable to those of the Silesian Unit and reflect a similar shallow nearshore sea. In the BCB, uppermost Cenomanian is marked by the last occurrence (LO) of Axopodorhabdus albianus and first occurrence (FO) of Quadrum intermedium (6 and 7 elements) and lowermost Turonian by a sudden quantitative rise in nannoflora and by the FO Eprolithus octopetalus. First Eiffellithus eximius and thus the base of the UC8 Zone was recorded in the upper part of ammonite Zone Collignoniceras woollgari in the lower Middle Turonian. Lithastrinus grillii is the stratigraphically youngest nannofossil species in this region and indicates the uppermost Coniacian. In the OWC, the Albian-Cenomanian boundary was recorded in the Silesian Unit and is marked by the LO Crucicribrum anglicum and FO Prediscosphaera cretacea and Corollithion kennedyi in the uppermost Albian. The Turonian-Coniacian boundary found both in the BCB and Waschberg-Ždánice-Subsilesian Unit, OWC is indicated by the FO Broinsonia parca expansa and by the base of the interval with common Marthasterites furcatus. In both areas, events were found closely below the FO inoceramid species Cremnoceramus waltersdorfensis. The Coniacian-Santonian boundary interval (Waschberg-Ždánice-Subsilesian and Foremagura Units, OWC) is indicated by Lithastrinus grillii occasionally accompanied by Lucianorhabdus ex gr. cayeuxii, Hexalithus sp. and Arkhangelskiella specillata.

Anisotropy of magnetic susceptibility (AMS) of impact melt breccia and target rocks from the Dhala impact structure, India

2021 ◽  
Author(s):  
Anuj Kumar Singh ◽  
Jayanta Kumar Pati ◽  
Shiva Kumar Patil ◽  
Wolf Uwe Reimold ◽  
Arun Kumar Rao ◽  
...  
Keyword(s):  
Magnetic Susceptibility ◽  
Anisotropy Of Magnetic Susceptibility ◽  
Impact Structure ◽  
Magnetic Phases ◽  
Impact Melt ◽  
Rock Samples ◽  
Average Value ◽  
Magnetic Fabrics ◽  
Target Rock ◽  
The Impact

ABSTRACT The ~11-km-wide, Paleoproterozoic Dhala impact structure in north-central India comprises voluminous exposures of impact melt breccia. These outcrops are discontinuously spread over a length of ~6 km in a semicircular pattern along the northern, inner limit of the monomict breccia ring around the central elevated area. This study of the magnetic fabrics of impact breccias and target rocks from the Dhala impact structure identified a weak preferred magnetic orientation for pre-impact crystalline target rocks. The pre- and synimpact rocks from Dhala have magnetite and ilmenite as common magnetic phases. The distributions of magnetic vectors are random for most impact melt breccia samples, but some do indicate a preferred orientation. Our anisotropy of magnetic susceptibility (AMS) data demonstrate that the shape of susceptibility ellipsoids for the target rocks varies from prolate to oblate, and most impact melt breccia samples display both shapes, with a slight bias toward the oblate geometry. The average value for the corrected degree of anisotropy of impact melt rock (P′ = 1.009) is lower than that for the target rocks (P′ = 1.091). The present study also shows that both impact melt breccia and target rock samples of the Dhala structure have undergone minor postimpact alteration, and have similar compositions in terms of magnetic phases and high viscosity. Fine-grained iron oxide or hydroxide is the main alteration phase in impact melt rocks. Impact melt rocks gave a narrow range of mean magnetic susceptibility (Km) and P′ values, in contrast to the target rock samples, which gave Km = 0.05–12.9 × 10−3 standard international units (SI) and P′ = 1.036–1.283. This suggests similar viscosity of the source magma, and limited difference in the degrees of recorded deformation. Between Pagra and Maniar villages, the Km value of impact melt breccias gradually decreases in a clockwise direction, with a maximum value observed near Pagra (Km = 1.67 × 10−3 SI). The poor grouping of magnetic fabrics for most impact melt rock samples implies local turbulence in rapidly cooled impact melt at the front of the melt flow immediately after the impact. The mean K1 for most impact melt samples suggests subhorizontal (<5°) flow in various directions. The average value of Km for the target rocks (4.41 × 10−3 SI) is much higher compared to the value for melt breccias (1.09 × 10−3 SI). The results of this study suggest that the melt breccias were likely part of a sheet-like body of sizeable extent. Our magnetic fabric data are also supported by earlier core drilling information from ~70 locations, with coring depths reaching to −500 m. Our extensive field observations combined with available widespread subsurface data imply that the impact melt sheet could have covered as much as 12 km2 in the Dhala structure, with an estimated minimum melt volume of ~2.4 km3.

scholarly journals Structure and dynamics of deep-seated slope failures in the Magura Flysch Nappe, outer Western Carpathians (Czech Republic)

2004 ◽  
Vol 4 (4) ◽  
pp. 549-562 ◽  
Author(s):  
I. Baron ◽  
V. Cilek ◽  
O. Krejci ◽  
R. Melichar ◽  
F. Hubatka
Keyword(s):  
Czech Republic ◽  
Slope Failure ◽  
Interdisciplinary Approach ◽  
Failure Surface ◽  
Late Glacial ◽  
Western Carpathians ◽  
Mass Movements ◽  
Slope Failures ◽  
Total Displacement ◽  
Outer Western Carpathians

Abstract. Deep-seated mass movements currently comprise one of the main morphogenetic processes in the Flysch Belt of the Western Carpathians of Central Europe. These mass movements result in a large spectrum of slope failures, depending on the type of movement and the nature of the bedrock. This paper presents the results of a detailed survey and reconstruction of three distinct deep-seated slope failures in the Raca Unit of the Magura Nappe, Flysch Belt of the Western Carpathians in the Czech Republic. An interdisciplinary approach has enabled a global view of the dynamics and development of these deep-seated slope failures. The three cases considered here have revealed a complex, poly-phase development of slope failure. They are deep-seated ones with depths to the failure surface ranging from 50 to 110m. They differ in mechanism of movement, failure structure, current activity, and total displacement. The main factors influencing their development have been flysch-bedrock structure, lithology, faulting by bedrock separation (which enabled further weakening through deep weathering), geomorphic setting, swelling of smectite-rich clays, and finally heavy rainfall. All of the slope failures considered here seem to have originated during humid phases of the Holocene or during the Late Glacial.

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