scholarly journals Famenian palynostratigraphy of the Volyn–Podillya margin of the East–Europian platform

Author(s):  
Antonina V. Ivanina

Famenian carbonate-terrigenous deposits with thickness іn 300-580 m are widely distributed within the Volyn-Podillia margin of the East-European platform. It is the facies-varying complex of rocks, the stratification of which is very difficult because there are no faunal remains in the sediments (with the exception of the lower part). Therefore, during the study of this stratum, the palynological method and the palynostratigraphic division are very important. The main purposes of this study are to identify palynozones, distinguish their generalized description and to create a local scale of the palynological zonation - the vertical succesion of biozones. The material for research consists of more than 450 samples, selected from 31 boreholes. The main method is the facial-palynological analysis, or the method of palynoorictocenosis. This is the first study to perform the standardized description of the biostratigraphic units determined by the palynological data for the Famennian of the Volyn-Podillia margin of the East-European platform. In general, five palynozones are allocated in the Famennian. All palynozones are comprehensively documented thanks to numerous palynological data, characterized by a zonal spore assemblage, in the structure of which there are following categories of taxa: based on the vertical range characteristics - key, characteristic, transit ones; on the content - subdominant, accessory. According to spreading peculiarities of key and characteristic species the following types of bio-units are identified: the Range-Zone (two units) and the Concurent-Range Zone (three ones). General the Famenian deposits of the Volyn-Podillia margin of the East-European platform were palynologically subdivided into lebedianensis–magnificus (the oldest zone), varicornata, cassis–lupinovitchi, versabilis –hamulus, lepidophyta (the youngest unit) miospore zones. Palynozones with a thickness from 17 to 231 m are laterally widespreaded, recorded from a number of boreholes within Volyn-Podillya. They have a set of palynological features that allow easy recognition of deposits. Palynozones detail the sequence bedding, complement the paleontological characteristic and form the local palynological zonal scheme of the Famenian of the Volyn-Podillia margin of the East-European platform.

Palaeobotany ◽  
2012 ◽  
Vol 3 ◽  
pp. 5-11
Author(s):  
A. V. Gomankov ◽  
V. F. Tarasevich

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.


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

2020 ◽  
Vol 157 (12) ◽  
pp. 2081-2088
Author(s):  
Sergey B Felitsyn ◽  
Eugeny S. Bogomolov

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.


2021 ◽  
Author(s):  
Alvina Chistyakova ◽  
Roman Veselovskiy

<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>


2021 ◽  
Author(s):  
Mikhail Kaban ◽  
Alexei Gvishiani ◽  
Roman Sidorov ◽  
Alexei Oshchenko ◽  
Roman Krasnoperov

<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>


2018 ◽  
Vol 480 (1) ◽  
pp. 611-614
Author(s):  
D. A. Bushnev ◽  
N. S. Burdelnaya ◽  
I. V. Goncharov ◽  
V. V. Samoylenko ◽  
M. A. Veklich

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