pdf № 312, December

DOI: 10.19110/geov.2020.12.1

This article presents new data on ostracodes and their stratigraphic distribution in the boundary deposits of the Devonian and Carboniferous (D₃-C₁) in the reference section Kamenka River (Pechora Uplift). The positions of the Kamenka River section and stratotypic sections of the southern Urals relative to the transgressive-regressive sequence are considered. The ostracode assemblage of the Ps. venulosa — Cor. alba — Cr. primaris zone, which occurs in the section on the Kamenka River and appears in sections of the southern Urals from the base of this zone, is represented by the following taxa: Pseudoleperditia venulosa (Kummerov), Coryellina alba Kotschetkova, Bairdia zaninae Posner, Blessites feluyensis Tschigova, Shishaella alekseevae Tschigova, Knoxiella complanata (Kummerov), Cavellina subeichwaldi Buschmina. The taxonomic characteristics of the upper part of the Pseudoleperditia venulosa — Coryellina alba — Cribroconcha primaris ostracode zone (Gumerovian Regional Substage (Horizon)) are supplemented Acratia subordinaria Buschmina, Healdianella ex gr. alba Lethiers, Phlyctiscapha ? pusilla Gurevitsсh, Pustulobairdia ex gr. confragosa (S. et Sm.), Acanthoscapha pechorica Sobolev, Acratina romboiformis Sobolev, and Rectobairdia eleganta Sobolev first appear at this level A gradual and insignificant change in the ostracode association is observed during the transition from the Gumerovian Horizon to the Malevkian Horizon, which precludes drawing the boundary between them. It is suggested that it would have been more appropriate to draw the boundary at the base of the global Hangenberg transgressive event near the base of the Ps. venulosa — Cor. alba — Cr. primaris ostracode zone (South Urals), which coincides with the initial phase of this transgression.

Keywords: ostracodes, Upper Devonian, Lower Carboniferous, stratigraphy, correlation, Gumerovo Horizon, Pechora Uplift.

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DOI: 10.19110/geov.2020.12.2

The study of samples of volcanic rocks, sulfide ores, and near-ore metasomatites from the bottom of the Atlantic Ocean resulted in the discovery of vital forms of organisms: foraminiferal shells, mineral pseudomorphs after the bodies of polychaetes, deposit feeders, and other fauna. This allows us to understand not only modern geological processes in the depths of the oceans, but also to reconstruct events of the distant geological past based on the principle of actualism.

Keywords: Mid-Atlantic Ridge, deep-sea fauna, picrites, basalts, tuffites, deep-sea sulfide ores, near-ore metasomatites.

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DOI: 10.19110/geov.2020.12.3

For the purposes of modeling and classification of structures and textures of bimineral rocks, a diagram of a new type is proposed — a barycentric tetrahedron (p_iii, p_iij, p_ijj, p_jjj) of probabilities of ternary intergrain contacts. The position of the Hardy-Weinberg equilibrium line is calculated. Correspondences between the classification fields and boundaries in the barycentric tetrahedron and the previously proposed barycentric triangle (p_ii, p_ij, p_jj) of the probabilities of binary intergrain contacts are established. The prospects for the classification of petrographic structures and textures in a barycentric tetrahedron based on Newton's classification of curves of the 3^rd order are discussed.

Keywords: crystalline rocks, petrographic structures and textures, Hardy-Weinberg equilibrium.

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DOI: 10.19110/geov.2020.12.4

The paper briefly describes the repositories of the Geological Museum, consisting of more than 600 monographic and exhibition collections. The paper also highlights the research, educational, exposition and exhibition activities of a highly qualified researcher, curator of the Geological Museum named after A. A. Chernov Liliya Raikovna Zhdanova on the occasion of her 60th birthday. The most important directions of activity and main achievements of L. R. Zhdanova are characterized. Main publications are named, including the unique monograph «Collection of holotypes of the paleontological collection of the Geological Museum named after A. A. Chernov» published in 2020.

Keywords: paleontological collections, paleontological species, holotype, researchers' names in taxonomic names, catalog, museum repository.

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