Ore-bearing potential of the southeastern part of the East European Platform exemplified by the Saratov region

2010 ◽  
Vol 431 (1) ◽  
pp. 312-313
Author(s):  
O. A. Likhoman ◽  
Yu. V. Van’shin
Keyword(s):  
East European Platform ◽  
Southeastern Part ◽  
Saratov Region ◽  
East European

scholarly journals Early Cambrian syenite and monzonite magmatism in the southeast of the East European Platform: petrogenesis and tectonic setting

2019 ◽  
Vol 27 (4) ◽  
pp. 357-400
Author(s):  
A. A. Nosova ◽  
A. A. Voznyak ◽  
S. V. Bogdanova ◽  
K. A. Savko ◽  
N. M. Lebedeva ◽  
...  
Keyword(s):  
Lithospheric Mantle ◽  
East European Platform ◽  
Tectonic Setting ◽  
Geochemical Data ◽  
Early Cambrian ◽  
Southeastern Part ◽  
East European ◽  
Isotopic Compositions ◽  
Time Period ◽  
Feature Negative

The paper reports new geochronological, petrological, and isotope-geochemical data on the syenites and alkali syenites of the Artyushki massif, and the monzonites of the Gusikha massif. These massifs are located along the southwestern and northeastern margins of the Pachelma aulacogen, in the southeastern part of the East European Platform (EEP). They have Early Cambrian ages of 524 ± 3 (Artyushki) and 514 ± 2 Ma (Gusikha) obtained by the U-Pb zircon method and similar ages of amphibole and K-feldspar by the 40Ar/39Ar method. This time period has previously been regarded as amagmatic in the EEP evolution. The Artyushki massif is made up of Amp-Cpx syenite porphyries and Grt-Cpx alkali syenite porphyries and their fenitized varieties. As compared to the Amp-Cpx varieties the Grt-Cpx rocks are more peralkaline (A/NK > 0.9) and have higher LREE and HFSE, and fractionated HREE patterns. The metasomatized (fenitized) varieties are more potassic and bear geochemical evidence of fluid reworking (high Y/Ho ratios, significant Zn variations, and etc.). Bulk samples have weakly radiogenic Sr isotopic compositions: (87Sr/86Sr)520 are within 0.703066–0.703615. The values of εNd(520) vary from –0.69 to +1.64. The Grt-Cpx syenite porphyries have the positive εNd(520), while the Amp-Cpx and fenitized syenite porphyries feature negative εNd. The Gusikha massif consists of biotite-amphibole and biotite monzonites. Similar to the Artyushki syenites in SiO2 contents, the Gusikha monzonites have higher Mg# (0.22–0.54 and 0.34–0.71 for the Artyushki and Gusikha massifs, respectively). They are also characterized by a negative Nb-Ta anomaly (Nb/Nb* = 0.5), high Ва/Sr ratio, and highly radiogenic (87Sr/86Sr)520 = 0.705204 and 0.705320. Their Nd-isotopic compositions correspond to εNd(520) = –6.7 and –7.0. Two melts contributed to the formation of the Artyushki massif. One was a strongly contaminated melt (Amp-Cpx syenite porphyries, the other was weakly contaminated (Grt-Cpx syenite porphyries). The main contribution was phonolitic melt derived from the melting of a moderately metasomatized (carbonate- and amphibole-bearing) shallow lithospheric mantle. The earliest and deepest melt portions were carbonate-silicate in composition. The geochemical, as well as the Sr and Nd isotopic compositions of the Gusikha monzonites indicate a predominant crustal contribution and pervasive reworking of the lithospheric mantle beneath southeastern Volgo-Uralia of the EEP in the Mesoproterozoic. Both massifs feature the geochemistry of within-plate and supra-subduction derivatives, which suggests a postorogenic tectonic setting of the magmatism. The presence of the Early Cambrian postorogenic magmatism within the East European Platform/Baltica is direct evidence for the involvement of Baltica in the collisional and/or accretionary events during the terminal Neoproterozoic – the beginning of the Paleozoic. This suggests reworking of the lithospheric mantle of Baltica during its collision with Timanian and East Avalonian/Cadomian terranes, including Scythia.

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>

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