pdf № 277, January

DOI: 10.19110/2221-1381-2018-1-3-11

Two mutually exclusive points of view on the origin of boulder loams are considered, the problem of Genesis, which despite more than a century-long history of the study of Quaternary sediments in the European North-East of Russia, is still debated. Our studies confirmed the importance of a complex lithological research of the Pleistocene sediments to establish their genetic origin. Genetic features of boulder loams characterizing them as moraines of cover continental glaciers are discussed. Examples of a subjective interpretation of published geological facts by adherents of the marinistic concept of the genesis of boulder loam are given.

Keywords: Pleistocene, boulder loam, Genesis, Quaternary sediments, complex research, glacialism, marinism.

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DOI: 10.19110/2221-1381-2018-1-12-18

This work presents a new stratigraphic scheme of the Upper Cambrian — Ordovician Pay-Khoy. It comprises all the information currently available on sedimentary and volcanic formations. Two stratigraphic regions have been identified as part of the Pay-Khoy subzone of the Lemva zone for the Upper Dapingian — Hirnantian. In the first isolated Yambpei region deposits that can be attributed to transitional facies between the shelf formations of the Elets zone and the deep-water formations of the Lemvinskaya zone are described. The new Severnyy Ruchey formation was distinguished in the volume of the upper part of the Hengur formation in the Central-Pay-Khoy district. All local stratigraphic units are brought into combliance with the Stratigraphic Code.

Keywords: Pay-Khoy, Ugra Peninsula, Ordovician, Upper Cambrian, local stratigraphic scheme, formation, Lakorsale Formation, Severnyy Ruchey Formation, Oyu sedimentary and volcanic Formation, Taripat-Yakha Formation, Yambpe Formation, Velikaya Reka Formation.

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DOI: 10.19110/2221-1381-2018-1-19-24

Distribution and morphology of pores and “canals” in the albid tissue of conodont elements of orders Ozarkodinida Dzik 1976 (Mehlina Youngquist, Youngquistognathus Myshkina et Zhuravlev, Polygnathus Hinde, Bispathodus Müller), Prioniodontida Dzik 1976 (Jablonnodus Dzik), and Priniodinida Sweet 1988 (Ligonodina Bassler) are studied by light microscopy, SEM, and X-ray micro-CT. Taxonomical differences (at the generic level) of morphology of the pore-and-canal system of conodont elements promise systematical application of these features. Similarity in the composition of the pore-and-canal system in elements of the apparatus of Youngquistognathus suggests a chance to use the composition in reconstructing apparatuses on the basis of disjuncted conodont elements.

Keywords: Conodonta, histology, Late Devonian.

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DOI: 10.19110/2221-1381-2018-1-25-44

Preliminary results of the field studies of the Upper Devonian deposits from the south-western part of North Timan are presented. Lithological peculiarities, paleosol profiles, ichnofossil associations, plant and vertebrate communities of the Ust’-Bezmoshitsa, Kamenny and Pokayama Formations are characterized. Facial conditions and deltaic environments of formation of the studied deposits are discussed.

Keywords: Devonian, delta plain, lithology, paleosols, trace fossils, fossil plants, lignite coals, fossil vertebrates, North Timan.

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