scholarly journals Biostratigraphy and lithofacies of the Viséan and Serpukhovian deposits of the southeast of the East European platform

2019 ◽  
Vol 27 (6) ◽  
pp. 3-28
Author(s):  
E. I. Kulagina ◽  
E. N. Gorozhanina ◽  
V. M. Gorozhanin ◽  
T. V. Filimonova

This paper presents new data on the biostratigraphy and sedimentology of Upper Visan and Serpukhovian deposits (Lower Carboniferous) from boreholes in the southeast of the East European Platform around the Sol-Iletsk Swell (Orenburg region). Based on rock lithology, sublatitudinal facies zones are recognized in the studied area. The deposits are represented by open shallow shelf facies, up to 500 m thick, in the area of the Sol-Iletsk Swell and near-side zone of the Preuralian Foredeep. To the south, at the margin of the Northern Pericaspian, their thickness sharply decreases to 36 m, and the succession is composed of carbonate-clay sediments of the relatively deep shelf. Based on foraminifers and conodonts, the Upper Visan and Serpukhovian are subdivided using the horizons of the stratigraphic scheme of the East European Platform, and foraminiferal zones are recognized. The base of the Serpukhovian in the high-energy shallow-water facies of the open shelf is drawn at the entry of the foraminifers Janischewskina delicata and Endothyranopsis plana; in lower-energy facies, it is placed at the level of the first appearance of Neoarchaediscus postrugosus; in the clay-carbonate facies of the relatively deep shelf it is based on the appearance of the conodont Lochriea ziegleri. The distribution of microfauna from the five boreholes, the characteristics of the foraminiferal zonal assemblages, and the interregional correlation are discussed.

2018 ◽  
Vol 92 (4) ◽  
pp. 681-712
Author(s):  
William I. Ausich ◽  
Elizabeth C. Rhenberg ◽  
David L. Meyer

AbstractThe Batocrinidae are characteristic faunal elements in Lower Mississippian shallow-marine settings in North America. Recent delineation of objectively defined genera allows a reexamination of batocrinid species and their distribution in the Fort Payne Formation (early Viséan, late Osagean), a well-studied array of carbonate and siliciclastic facies. The Fort Payne batocrinid fauna has 14 species assigned to six genera, plus hybrid specimens.Magnuscrinus spinosus(Miller and Gurley, 1895a) is reassigned to its original placement inEretmocrinus. Hybrid specimens (Ausich and Meyer, 1994) are regarded asEretmocrinus magnificus×Eretmocrinus spinosus.Macrocrinus casualisis the dominant species ofMacrocrinusin the Fort Payne, andM.mundulusandM.strotobasilarisare recognized in the Fort Payne Formation for the first time.Magnuscrinus cumberlandensisn. sp. is named, 13 species are designated as junior synonyms, the name for the hybrid specimens is changed toEretmocrinus magnificus×Eretmocrinus spinosus, and the previous occurrences of two species in the Fort Payne are rejected. The Eastern Interior Seaway was a mixed carbonate-siliciclastic setting with both shallow- and deep-water epicontinental sea facies ranging from relatively shallow autochthonous green shales to deep-water turbidite facies.Dizygocrinuswas restricted to shallow-water carbonate and siliciclastic facies,Eutrochocrinuswas restricted to shallow-water carbonate facies, andMagnuscrinuswas restricted to deep-water facies. Species distributions varied fromAbatocrinus steropes,Alloprosallocrinus conicus,Macrocrinus mundulus, andUperocrinus nashvillae, which occurred throughout the Eastern Interior Seaway, to species that were restricted to a single facies.Eretmocrinus magnificus,Alloprosallocrinus conicus, andUperocrinus robustuswere the dominant batocrinids in the Fort Payne Formation.UUID:http://zoobank.org/703aafd8-4c73-4edc-9870-e2356e2d28b8


2019 ◽  
Vol 34 (4) ◽  
pp. 1703-1721 ◽  
Author(s):  
Farid Bolourchifard ◽  
Farajollah Fayazi ◽  
Behzad Mehrabi ◽  
Ayyub Memarkouchehbagh

2019 ◽  
Vol 94 (2) ◽  
pp. 255-265 ◽  
Author(s):  
Jan Ove R. Ebbestad ◽  
Juan Carlos Gutiérrez-Marco

AbstractPhragmolites lissoni new species is described from 11 specimens found in the Sandbian Calapuja Formation near Calapuja in Peru. The deposits are part of the Central Andean Basin. This is the hitherto only systematically described Ordovician gastropod from Peru. The species is from a brachiopod-dominated siliciclastic sequence and is associated with bryozoans. Most specimens are preserved as external molds, but latex casts yield excellent details of shell ornamentation and are used as a basis for evaluating this feature in the genus. The characteristic ornamentation of Phragmolites should be called corrugated lamellae, and the individual elements on these should be referred to as flutes. A descriptive terminology for these is suggested. The development and shape of the corrugated lamellae and flutes could be biomechanical process. A second component in lamellar formation is the alternation between regular incremental growth and formation of a lamella. Phragmolites is mainly found in shallow-water carbonate facies from tropical latitudes in the Sandbian and a mid-latitude presence in Peru is unexpected. Brachiopods from the same section in Calapuja show affinities with faunas of the Mediterranean margin of Gondwana but also weak links with Avalonia. Phragmolites is found abundantly in deeper-water facies in Laurentia, and a broad tolerance to facies and temperature and possible planktotrophy might have allowed a wide geographical dispersal of the genus. The scant record of Ordovician gastropods in the Central Andean Basin precludes comparison with the disparate record of the Ordovician gastropod taxa from the Precordillera, which do not include Phragmolites.UUID: http://zoobank.org/References/fbd7a43e-a610-42fd-a31d-b1a16fa69c9b


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.


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