scholarly journals Chromite Paleoplacer in the Permian Sediments at the East Edge of the East European Platform: Composition and Potential Sources

Minerals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 691
Author(s):  
Ildar R. Rakhimov ◽  
Evgenii V. Pushkarev ◽  
Irina A. Gottman
Keyword(s):  
East European Platform ◽  
Melt Inclusions ◽  
Volcanic Rocks ◽  
Compositional Analysis ◽  
Transitional Zone ◽  
Ural Region ◽  
Additional Source ◽  
East European ◽  
Chromite Ore ◽  
Mantle Peridotites

A chromite occurrence called the Sabantuy paleoplacer was discovered in the Southern Pre-Ural region, at the east edge of the East-European Platform in the transitional zone to the Ural Foredeep. A ca. 1 m-thick chromite-bearing horizon is traced at a depth of 0.7–1.5 m from the earth’s surface for the area of ca. 15,000 m2. The chromspinel content in sandstones reaches 30–35%, maximum values of Cr2O3 are 16–17 wt.%. The grain size of detrital chromspinel ranges from 0.15 to 0.25 mm. Subangular octahedral crystals dominate; rounded grains and debris are rare. The composition of detrital chromspinel varies widely and is constrained by the substitution of Al3+ and Cr3+, Fe2+ and Mg2+ cations. Chemically, low-Al (Al2O3 = 12 wt.%) and high-Cr (Cr2O3 = 52–56 wt.%) chromspinel prevail. The compositional analysis using discrimination diagrams showed that most chromites correspond to mantle peridotites of subduction settings. Volcanic rocks could be an additional source for detrital chromites. It is confirmed by compositions of monomineralic, polymineralic and melt inclusions in chromspinels. The presented data indicates that ophiolite peridotites and related chromite ore associated with oceanic and island-arc volcanic rocks, widespread in the Ural orogen, could be the main sources of the detrital chromspinel of the Sabantuy paleoplacer.

scholarly journals Provenance of lower Palaeozoic metasediments of the East Odenwald (Mid-German-Crystalline Zone, Variscides)—a correlation with the East European Platform (Poland)

2021 ◽  
Author(s):  
Wolfgang Dörr ◽  
Eckhardt Stein ◽  
Ferdinand Kirchner ◽  
Henri Paul Meinaß ◽  
Felicitás Velledits
Keyword(s):  
East European Platform ◽  
Large Scale ◽  
Volcanic Rocks ◽  
Detrital Zircons ◽  
The South ◽  
Early Devonian ◽  
East European ◽  
Magmatic Arc ◽  
Tectonic Model ◽  
Lower Palaeozoic

AbstractU–Pb age spectra of detrital zircons related to the East European Platform could be traced in paragneiss through the whole Mid-German-Crystalline Zone (Variscides, Central Europe) from the Odenwald via the Spessart to the Ruhla crystalline forming an exotic unit between Armorica and Laurussia. The depositional ages of the paragneiss are defined by the youngest age of the detrital zircons and the oldest intrusion ages as Ordovician to Silurian. The Ediacaran dominated age spectrum of detrital zircons from the paragneiss of the East Odenwald suggests the latter to be derived from the shelf of the East European Platform (Baltica), which was influenced by the 1.5 Ga old detritus delivered from a giant intrusion (Mazury granitoid, Poland). The detrital zircon age spectrum of the lower Palaeozoic paragneiss of the East Odenwald and sandstone of the northern Holy Cross Mountains are identical. The pure Sveconorwegian spectrum of the lower Palaeozoic quartzite from the Spessart, (Kirchner and Albert Int J Earth Sci 2020) and the Ruhla (Zeh and Gerdes Gondwana Res 17:254–263, 2010) could be sourced from Bornholm and southern Sweden. A U–Pb age spectrum with 88% Palaeozoic detrital zircons from a volcano-sedimentary rock of the East Odenwald is interpreted to be derived from a Silurian magmatic arc (46%), which was probably generated during the drift of the Mid-German-Crystalline Zone micro-continent to the south. A tentative plate tectonic model of Mid-German-Crystalline Zone is presented taking into account (a) the East European Platform related age spectra of the detrital zircons (b) the Ordovician to Silurian depositional age of the metasediments (c) the Silurian and Early Devonian intrusion age of the plutonic and volcanic rocks and (d) the U–Pb ages of the Middle Devonian high-grade metamorphism. The East European Platform-related part of the Mid-German-Crystalline Zone is interpreted as a micro-continent, which drifted through the Rheic Ocean to the south and collided with the Saxothuringian (Armorican Terrane Assemblage) during the Early Devonian. Such large-scale tectonic transport from the northern continent to the southern continent is also known from the SW Iberia, where Laurussia-related metasediments of the Rheic suture zone are explained by a large scale tectonic escape (Braid et al. J Geol Soc Lond 168:383–392, 2011).

The morphology and ultrastructure of pollen grains of Scutasporites nanuki Utting (Sashiniaceae, Coniferales) from the Permian of the East-European Platform

Palaeobotany ◽  
2012 ◽  
Vol 3 ◽  
pp. 5-11
Author(s):  
A. V. Gomankov ◽  
V. F. Tarasevich
Keyword(s):  
East European Platform ◽  
Central Body ◽  
Pollen Grains ◽  
Irregular Shape ◽  
East European ◽  
Sem And Tem

Dispersed bisaccate pollen grains of Scutasporites nanuki were studied by means of LM, SEM and TEM. Sacci ultrastructure of these pollen grains was rather peculiar. Sacci were like a thin fi lmy fringe attached to the central body near the equator. They were fi lled with sporopollenin elements of irregular shape and various dimensions with equally various cavities between them. Such an ultrastructure is called as spongy. The morphology and ultrastructure of S. nanuki is discussed in the context of the evolution of early conifers.

The quasiplatform sediments of the East European Platform

2005 ◽  
Vol 7 (5) ◽  
pp. 1-12
Author(s):  
M. A. Nagornyi ◽  
V. G. Nikolaev
Keyword(s):  
East European Platform ◽  
East European

Nd isotope composition of the Ediacaran and earliest Cambrian phosphorite nodules and Fe sulphide from the East European Platform

2020 ◽  
Vol 157 (12) ◽  
pp. 2081-2088
Author(s):  
Sergey B Felitsyn ◽  
Eugeny S. Bogomolov
Keyword(s):  
East European Platform ◽  
Isotope Composition ◽  
Water Reservoir ◽  
Secular Change ◽  
Early Cambrian ◽  
Iron Sulphide ◽  
Nd Isotope ◽  
East European ◽  
Moscow Syneclise ◽  
Nd Isotope Composition

AbstractAn enhanced concentration of phosphorus has been found at the stratigraphic level of the disappearance of Ediacaran taxa in two areas, the Cis-Dniester region and the Moscow syneclise, on the East European Platform (EEP). The isotope composition of neodymium was determined in Fe sulphide and phosphorite in the same beds. Measured εNd(t) values in diagenetic phosphate nodules are similar to those in iron sulphide from the same layer. During the Ediacaran − Early Cambrian, accumulation of radiogenic Nd in the epeiric basins on the EEP increased progressively from −17.9 and −19.4 in pyrite from the sequence bottom to −7.9 and −8.5 in the Early Cambrian pyrite of the central part of the EEP. The Ediacaran phosphate nodules show εNd(t) ranging from −12.9 to −15.0, while that in the Early Cambrian nodules is typically c. −9.0. These data indicate the secular change in Nd isotope composition of the water reservoir on the EEP from Ediacaran to Cambrian.

Stratigraphic correlation of the Permian-Triassic red beds constrained by detrital zircon geochronology: Moscow basin, East European platform

2021 ◽  
Author(s):  
Alvina Chistyakova ◽  
Roman Veselovskiy
Keyword(s):  
Detrital Zircon ◽  
East European Platform ◽  
Lower Triassic ◽  
Detrital Zircons ◽  
Upper Permian ◽  
Stratigraphic Correlation ◽  
Red Beds ◽  
East European ◽  
Moscow Basin ◽  
Stratigraphic Position

<p>There's no doubt that nowadays detrital zircon U-Pb geochronology is actually required method of sedimentary basins analysis. Furthermore, this approach may have a lot of applications, such as a stratigraphic correlation. Here we present the first results of U–Pb LA–ICP–MS dating of detrital zircon from the Permian-Triassic red beds located within the Moscow Basin of the East European platform. Two outcrops have been studied: the Zhukov Ravine P/T boundary reference section and the Nedubrovo strata with uncertain stratigraphic position (uppermost Permian or lower Triassic?).</p><p>U–Pb ages of detrital zircon grains have been obtained for two samples – the Upper Permian and Lower Triassic age, which were taken in the proximity to the Permian–Triassic boundary in the Zhukov Ravine. Corresponding age distributions show contrasting provenance of the studied sedimentary rocks, pointing out that principal change in source of clastic material occurred on the Paleozoic-Mesozoic boundary. It means that detrital zircon U–Pb geochronology can be used as an additional independent tool for stratigraphic correlation of the Permian-Triassic red beds, at least within the Moscow Basin. We demonstrate this in the case of the Nedubrovo section with debated (Permian or Triassic?) stratigraphic position: the obtained data on detrital zircons persuasively suggests Early Triassic age of the Nedubrovo strata.</p><p>This study is supported by the Russian Foundation for Basic Research (project no. 18-05-00593).</p>

A new sedimentary cover model for the southern area of the East European Platform and the Pre-Caucasus based on decompensation gravity anomalies data

2021 ◽  
Author(s):  
Mikhail Kaban ◽  
Alexei Gvishiani ◽  
Roman Sidorov ◽  
Alexei Oshchenko ◽  
Roman Krasnoperov
Keyword(s):  
East European Platform ◽  
Sedimentary Cover ◽  
Gravity Anomalies ◽  
Sedimentary Basins ◽  
The Caucasus ◽  
Near Surface ◽  
New Model ◽  
Origin And Evolution ◽  
East European ◽  
Bouguer Anomalies

<p><span>A new model has been developed for the density and thickness of the sedimentary cover in a vast region at the junction of the southern part of the East European Platform, the Pre-Caucasus and some structures adjacent to the south, including the Caucasus. Structure and density of sedimentary basins was studied by employing the approach based on decompensation of gravity anomalies. Decompensative correction for gravity anomalies reduces the effect of deep masses providing compensation of near-surface density anomalies, in contrast to the conventional isostatic or Bouguer anomalies. . The new model of sediments, which implies their thickness and density, gives a more detailed description of the sedimentary thickness and density and reveals new features which were not or differently imaged by previous studies. It helps in better understanding of the origin and evolution of the basins and provides a background for further detailed geological and geophysical studies of the region.</span></p>

Comparison of Organic Matter from Upper Jurassic Oil Shale of the East European Platform and the Bazhenov Formation by Molecular and Isotopic Data

2018 ◽  
Vol 480 (1) ◽  
pp. 611-614
Author(s):  
D. A. Bushnev ◽  
N. S. Burdelnaya ◽  
I. V. Goncharov ◽  
V. V. Samoylenko ◽  
M. A. Veklich
Keyword(s):  
Organic Matter ◽  
East European Platform ◽  
Oil Shale ◽  
Upper Jurassic ◽  
Isotopic Data ◽  
Bazhenov Formation ◽  
East European
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