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.

scholarly journals Geochemical Characterization and Presence of Rare Earth Elements in the Recent Depositions at the Islands of the Eastern Bay of Bengal, Bangladesh

2020 ◽  
Vol 11 (1) ◽  
pp. 40-47
Author(s):  
Farah Deeba ◽  
Syed Hafizur Rahman ◽  
Mohammad Zafrul Kabir ◽  
Mohammad Rajib
Keyword(s):  
Rare Earth ◽  
Chemical Composition ◽  
Rare Earth Elements ◽  
Bay Of Bengal ◽  
Heavy Mineral ◽  
Heavy Minerals ◽  
Mineral Concentration ◽  
Near Surface ◽  
Geochemical Characterization ◽  
X Ray

This study presents geochemical characterization, as well as, quantification of rare earth elements in the recent beach deposition at the two major islands of the eastern Bay of Bengal-Kutubdia and Moheshkhali. Placer sand samples from near surface depositions were analyzed by heavy mineral separation, mineralogical identification, chemical composition and elemental mapping. X-ray diffraction (XRD), X-ray fluorescence (XRF), Scanning Electron Microscopy with Energy Dispersive Spectroscopy (SEM-EDS) were used to obtain these results. The heavy mineral concentration in different raw sand samples resulted by heavy liquid separation technique revealed that the average abundance of heavy minerals is 69.67% in Kutubdia island and 9.32% in Moheshkhali island, respectively. The X-ray patterns of Kutubdia and Moheshkhali sand samples show the presence of zircon, quartz, hematite, magnetite, ilmenite, chromite, kyanite, anatase, rutile and garnet. Chemical composition of heavy mineral sands from Kutubdia and Moheshkhali islands were analyzed using X-ray fluorescence method (XRF) for major oxides and trace elements. The concentration is of Na2O, MgO, Al2O3, SiO2, P, K2O, CaO, TiO2, V2O5, Cr2O3, MnO, Fe2O3, CoO, ZnO, SrO, Y2O3 ZrO2, Nb2O5, MoO3, HfO2, WO3, ThO2, U3O8, CeO2, Nd2O and Er2O3 were determined. A significant amount of various rare earth elements (REEs) in the elemental composition of few samples was also identified. The study is expected to be useful in the baseline and environmental aspects of both the islands.

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.

Paleogeographic implications of a multi-parameter Paleogene provenance dataset (Transylvanian Basin, Romania)

2021 ◽  
Vol 91 (6) ◽  
pp. 551-570
Author(s):  
Gabriella Obbágy ◽  
István Dunkl ◽  
Sándor Józsa ◽  
Lóránd Silye ◽  
Róbert Arató ◽  
...  
Keyword(s):  
Sedimentary Environment ◽  
Volcanic Rocks ◽  
Heavy Mineral ◽  
Heavy Minerals ◽  
Second Phase ◽  
Provenance Analysis ◽  
Drainage Patterns ◽  
Mineral Associations ◽  
Recent Developments ◽  
Felsic Volcanic

ABSTRACT Recent developments in geoanalytics have led to the rapidly increasing potential of sedimentary provenance analysis in paleogeographic reconstructions. Here we combine standard methods (petrography, zircon U-Pb geochronology, optical heavy-mineral identification) with modern techniques such as automated Raman-spectroscopic identification of heavy minerals and detrital apatite and titanite U-Pb geochronology. The resulting multi-parameter dataset enables the reconstruction of tectonic and paleogeographic environments to an as-yet unprecedented accuracy in space and time. The Paleogene siliciclastic formations of our study area, the Transylvanian Basin, represent an intensely changing sedimentary environment comprising three transgressive–regressive cycles on a simultaneously moving and rotating tectonic plate. We identified six major source components of the Paleogene sediments and outlined the paleo-drainage patterns for the three cycles, respectively. According to our data these components include: 1) pre-Variscan basement units of the nappes, 2) Variscan granitoids, 3) Permo-Triassic felsic volcanic rocks, 4) Jurassic ophiolites, 5) Upper Cretaceous granodiorites, and 6) Priabonian to Rupelian (37–30 Ma) intermediate magmatites, the latter representing newly recognized formations in the region. Abrupt paleographic changes can be directly deduced from the obtained dataset. The first phase of the Paleogene siliciclastic sequence is composed of mostly Southern Carpathian–derived sediments, to which Jurassic ophiolite detritus of the Apuseni Mts. was added during the second phase, while the siliciclastic material of the third phase represents mainly recycled material from the second phase. According to the detected diagnostic heavy-mineral associations, U-Pb age components and the positions of the potential source areas a set of provenance maps are presented.

scholarly journals Geochemical Characterization and Presence of Rare Earth Elements in the Recent Depositions at the Islands of the Eastern Bay of Bengal, Bangladesh

2020 ◽  
Vol 11 (1) ◽  
pp. 40-47
Author(s):  
Farah Deeba ◽  
Syed Hafizur Rahman ◽  
Mohammad Zafrul Kabir ◽  
Mohammad Rajib
Keyword(s):  
Rare Earth ◽  
Chemical Composition ◽  
Rare Earth Elements ◽  
Bay Of Bengal ◽  
Heavy Mineral ◽  
Heavy Minerals ◽  
Mineral Concentration ◽  
Near Surface ◽  
Geochemical Characterization ◽  
X Ray

This study presents geochemical characterization, as well as, quantification of rare earth elements in the recent beach deposition at the two major islands of the eastern Bay of Bengal-Kutubdia and Moheshkhali. Placer sand samples from near surface depositions were analyzed by heavy mineral separation, mineralogical identification, chemical composition and elemental mapping. X-ray diffraction (XRD), X-ray fluorescence (XRF), Scanning Electron Microscopy with Energy Dispersive Spectroscopy (SEM-EDS) were used to obtain these results. The heavy mineral concentration in different raw sand samples resulted by heavy liquid separation technique revealed that the average abundance of heavy minerals is 69.67% in Kutubdia island and 9.32% in Moheshkhali island, respectively. The X-ray patterns of Kutubdia and Moheshkhali sand samples show the presence of zircon, quartz, hematite, magnetite, ilmenite, chromite, kyanite, anatase, rutile and garnet. Chemical composition of heavy mineral sands from Kutubdia and Moheshkhali islands were analyzed using X-ray fluorescence method (XRF) for major oxides and trace elements. The concentration is of Na2O, MgO, Al2O3, SiO2, P, K2O, CaO, TiO2, V2O5, Cr2O3, MnO, Fe2O3, CoO, ZnO, SrO, Y2O3 ZrO2, Nb2O5, MoO3, HfO2, WO3, ThO2, U3O8, CeO2, Nd2O and Er2O3 were determined. A significant amount of various rare earth elements (REEs) in the elemental composition of few samples was also identified. The study is expected to be useful in the baseline and environmental aspects of both the islands.

scholarly journals Provenance of the detrital garnets and spinels from the Albian sediments of the Czorsztyn Unit (Pieniny Klippen Belt, Western Carpathians, Slovakia)

2009 ◽  
Vol 60 (6) ◽  
pp. 463-483 ◽  
Author(s):  
Roman Aubrecht ◽  
Štefan Méres ◽  
Milan Sýkora ◽  
Tomáš Mikuš
Keyword(s):  
Middle Jurassic ◽  
Alternative Interpretation ◽  
Heavy Mineral ◽  
Western Carpathians ◽  
Accretionary Wedge ◽  
Outer Western Carpathians ◽  
Pieniny Klippen Belt ◽  
Central Western Carpathians ◽  
Heavy Mineral Analysis ◽  
Back Arc

Provenance of the detrital garnets and spinels from the Albian sediments of the Czorsztyn Unit (Pieniny Klippen Belt, Western Carpathians, Slovakia)According to earlier concepts, the Czorsztyn Unit (Oravic Superunit, Pieniny Klippen Belt, Western Carpathians) sedimented on the isolated Czorsztyn Swell which existed in the Middle Jurassic-Late Cretaceous time in the realm of the Outer Western Carpathians. This paper brings new data providing an alternative interpretation of its Cretaceous evolution. They are based on heavy mineral analysis of the Upper Aptian/Lower Albian sediments of the Czorsztyn Unit. They rest upon a karstified surface after a Hauterivian-Aptian emersion and are represented by condensed, red marly organodetritic limestones with some terrigenous admixture (Chmielowa Formation). The heavy mineral spectrum is dominated by spinels, followed by garnet, with lesser amounts of zircon, rutile and tourmaline. The composition of the majority of the detrital garnets shows that they were derived from primary HP/UHP parental rocks which were recrystallized under granulite and amphibolite facies conditions. The garnets were most probably derived directly from the magmatic and metamorphic rocks of the Oravic basement, as the high-pyrope garnets are known to be abundant in Mesozoic sediments all over the Outer Western Carpathians. The presence of spinels is surprising. According to their chemistry, they were mostly derived from mid-oceanic ridge basalts (MORB) peridotites, supra-subduction zone peridotites (harzburgites) and transitional lherzolite/harzburgite types. Only a lesser amount of spinels was derived from volcanics of BABB composition (back-arc basin basalts). The presence of this ophiolitic detritus in the Czorsztyn Unit is difficult to explain. Ophiolitic detritus appeared in the Aptian/Albian time only in the units which were considered to be more distant, because they were situated at the boundary between the Central and the Outer Western Carpathians (Klape Unit, Tatric and Fatric domains). The hypothetical Exotic Ridge which represented an accretionary wedge in front of the overriding Western Carpathian internides was considered to be a source of the clastics. In previous paleogeographical reconstructions, the Czorsztyn Unit was situated north of the Pieniny Trough (considered to be one of the branches of the Penninic-Vahic Ocean). In the trough itself, the ophiolitic detritus appeared as late as in the Senonian and there was no way it could reach the Czorsztyn Swell which was considered to be an isolated elevation. The new results presented herein show that these reconstructions do not fit the obtained data and infer a possibility that the Czorsztyn sedimentary area was not isolated in the Cretaceous time and it was situated closer to the Central Carpathian units than previously thought. A new paleogeographical model of the evolution of the Pieniny Klippen Belt is presented in the paper: Oravic segment was derived from the Moldanubian Zone of the Bohemian Massif by the Middle Jurassic rifting which caused block tilting where most of the Oravic units were arranged north of the Czorsztyn Swell. The Oravic segment was situated in the lateral continuation of the Central and Inner Western Carpathians from which it was detached by later clockwise rotation. The Oravic segment was then laterally shifted in front of the Central Western Carpathians, together with remnants of the Meliatic suture zone which represented a source for the exotics to the Klape, Tatric, Fatric and Oravic units.

Geochemistry of fluid manifistations of the Ebeko Volcano, Paramushir Island (Kurile Islands, Russia).

2020 ◽  
Author(s):  
Elena Kalacheva ◽  
Tatiana Kotenko ◽  
Ekaterina Voloshina
Keyword(s):  
Chemical Composition ◽  
Thermal Field ◽  
Volcanic Rocks ◽  
Hydrothermal Activity ◽  
Trace Element Composition ◽  
Western Slope ◽  
Published Data ◽  
Fumarolic Activity ◽  
Volcanic Gas ◽  
Crater Lakes

<p>The Ebeko volcano (50°41′N, 156°01′E) is located at the northern part of Paramushir Island and composed of several Quaternary volcanic cones. The Neogene volcano-clastic basement occurs below ~200 m asl. The post-glacial cone of Ebeko is composed by lava flows and pyroclastics of andesitic composition. The summit is represented by three craters (Northern, Middle and Southern). The modern phreatic and fumarolic activity of Ebeko started after a strong explosive phreatic–magmatic eruption from the Middle crater in 1934–1935 which ejected about 10<sup>6</sup> t of andesitic ash and bombs. Last eruptive activity of Ebeko volcano began in October 2016 and continues to the present. </p><p>Main feature of the hydrothermal activity of Ebeko is the existence of two thermal fields separated in the space. The summit field consists ~ 10 thermal grounds, low-temperature fumaroles (<120 °C) and near-boiling pools with no or weak outflowrates. The second thermal field, Yurievskie springs, is locatedat low elevations, ~550 m asl down to 280 m asl, on the western slope of Ebeko volcano in the canyon of Yurieva River. Gases from different parts of the summit thermal field are all water-rich (97–99 mol%) and show varying contents of HCl and total sulfur and ratios of C/S and H<sub>2</sub>S/SO<sub>2</sub>. All waters from the Yurievskie springs and Ebeko pools are ultra-acidic, with pH < 2. The Yurievskie waters are of the SO<sub>4</sub>–Cl type (SO<sub>4</sub>/Cl ratios are ~1:1molar and 3:1 by weight), whereas the SO<sub>4</sub>/Cl ratio in Ebeko pools show low (<1) and varying SO<sub>4</sub>/Cl ratios. Major and trace element composition of Ebeko-Yurievskie acidic waters is suggesting congruent dissolution of volcanic rocks. Oxygen and hydrogen isotopic composition of water and Cl concentration for Yurieva springs show an excellent positive correlation, indicating a mixing between meteoric water and magmatic vapor. In contrast, volcanic gas condensates of Ebeko fumaroles do not show a simple mixing trend but rather a complicated data suggesting evaporation of the acidic brine. Temperatures calculated from gas compositions and isotope data are similar, ranging from 150 to 250 °C, which is consistent with the presence of a liquid aquifer below the Ebeko fumarolic fields.</p><p>Thermal grounds and pools of the summit field are closely associated with the volcano activity. Each period of volcano excitation causes changes in the locations of major fumarole vents, crater lakes, and affects the chemical composition of water and gas. The Ebeko volcano eruption (from 2016 to the present) also triggered changes in the isotope and chemical composition of the Yuryevskie springs.</p><p>In this paper we report data on water and gas compositions of samples obtained during the 2016-2019 field seasons and compare partially published data from 2005-2014 field campaigns. This work was supported by the RFBR grant #20-05-00517.</p>

On the provenance of mid-Cretaceous turbidites of the Pindos zone (Greece): implications from heavy mineral distribution, detrital zircon ages and chrome spinel chemistry

2006 ◽  
Vol 143 (3) ◽  
pp. 329-342 ◽  
Author(s):  
P. FAUPL ◽  
A. PAVLOPOULOS ◽  
U. KLÖTZLI ◽  
K. PETRAKAKIS
Keyword(s):  
Detrital Zircon ◽  
Heavy Mineral ◽  
Heavy Minerals ◽  
Chrome Spinel ◽  
Internal Source ◽  
Suprasubduction Zone ◽  
Mid Ocean Ridge ◽  
Detrital Zircon Ages ◽  
Back Arc ◽  
Ocean Ridge

Two heavy mineral populations characterize the siliciclastic material of the mid-Cretaceous turbidites of the Katafito Formation (‘First Flysch’) of the Pindos zone: a stable, zircon-rich group and an ophiolite-derived, chrome spinel-rich one. U/Pb and Pb/Pb dating on magmatic zircons from the stable heavy mineral group clearly illustrate the existence of Variscan magmatic complexes in the source terrain, but also provide evidence for magmatism as old as Precambrian. Based on microprobe analyses, the chrome spinel detritus was predominantly supplied from peridotites of mid-ocean ridge as well as suprasubduction zone origin. A small volcanic spinel population was mainly derived from MORB and back-arc basin basalts. The lithological variability of the mid-Cretaceous ophiolite bodies, based on spinel chemistry, is much broader than that of ophiolite complexes presently exposed in the Hellenides. The chrome spinel detritus compares closely with that from the Outer and Inner Dinarides. The source terrain of the ophiolite-derived heavy minerals was situated in a more internal palaeogeographic position than that of the Pindos zone. The zircon-rich heavy mineral group could have had either an external and/or an internal source, but the chrome spinel constantly accompanying the stable mineral detritus seems to be more indicative of an internal source terrain.

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