Vol 53 Iss. 2

Stratigraphy emerged during the differentiation of historical geology, The classic monographs of F. N. Chernyshev on the Devonian of the Urals, S. N. Nikitin on the Jurassic of the central regions are typical stratigraphic works. True, they were not called stratigraphic at that time. They were geological works connected with the geologic map. Stratigraphy existed as an undifferentiated part of geology, and later as a part of historical geology ...

Ordovician and Silurian sediments are quite widespread in the Altai-Sayan region. In describing the stratigraphy, tectonics, and history of geologic development of southern Siberia, many researchers have touched upon the paleogeography of certain areas in the Ordovician and Silurian. A. B. Ginzinger [1964] considered the paleogeography of Altai and Salair in the Ordovician in the most detail. M. S. Potapova gave the first detailed paleogeographic constructions for the Silurian of Altai. I. N. Kazakov [1965] and L. P. Zonenshain [1963] considered the geologic history of the Western Sayan in the Ordovician and Silurian periods

All researchers note the wide distribution of Ordovician sediments in the area of the Western Sayan, although the volume and structure of sediments attributed to the Ordovician are understood in different ways. In spite of sufficient geological study of the territory, the number of locations of remains of reliable Ordovician fauna is still measured here in units. One of these localities is the Karyn-Sug river. Karyn-Sug (according to I. B. Filippova) is located in the central part of the Western Sayan, the other two - the Manchurek River, the upper Manchurek River, and the upper Manchurek River. Manchurek River and the headwaters of the Ak-Sug River are located on its south-western edge, within Tuva. Locations of Ordovician fauna are also described on the northern and northeastern margins of Tuva - in the area of its interface with the Western Sayan ...

Finding out the depths of the seas of the geological past is of undoubted interest in the preparation of lithologic-paleogeographic maps, in establishing the conditions of formation of sediments, with which a number of deposits of sedimentary minerals are associated. There is a set of methods for determining the relative depth of ancient basins. The characterization of absolute depths of ancient seas is given on the basis of the principle of actualism. In particular, L. V. Rukhin, taking into account the spread of underwater erosions and algae in modern seas to a depth of 50-70 m, believed that “... these limit values are also applicable to ancient basins, as they are determined by physical factors almost unchanged with time”. Usually, however, greater depths are allowed. Since in modern seas the edge of the shelf, characterized by optimal conditions for organic life, passes at a depth of about 200 m, it is assumed that finds of organic remains in marine sediments indicate depths of up to 200 m ...

The region under consideration is located in the western part of the Zaisan Hercynian folded region, bounded in the southwest by the Caledonian structures of the Chingiz-Tarbagatai middle mass (geoanticlinal zone of the first kind, according to V. A. Nikolaev) and in the northeast by the Charsky uplift (internal geoanticline of the second kind, according to V. A. Nikolaev) .....

In 1963, the study of reference sections of the Lower Permian of the Western Urals provided an opportunity to study in detail complete, well exposed, faunistically richly characterized sections of the Shvagerian horizon of the Asselian Stage. Until then, complete sections of the Schwagerian horizon were not known on the western slope of the Middle Urals ...

The problems of paleobiogeographic zoning cover a wide range of issues, among which the ways of fauna and flora distribution occupy not the least place. Knowledge of the main communications linking paleobiogeographic provinces and districts makes it possible to correlate even distant territories with a high degree of reliability, to identify features of commonality of the environment, to establish the belonging of an area to a particular province or region. The detailed study allowed us to solve a number of interesting problems related to the distribution of Devonian four-beam corals ...

The schemes of subdivision of Permian sediments of southern areas based on microfauna are difficult to link with stratigraphic schemes of subdivision of Permian sediments of other areas, in particular, with the reference section of the Urals. This problem is solved only by the joint location of ammonoids and microfauna. More than ten locations of ammonoids of good preservation prove the wide distribution of ammonoids in the Permian sediments of the Pamir over the area and section. The main results of the processing of the collected materials on the age of individual formations and broad correlation of Permian deposits of different areas are presented earlier. The present work contains a description of a number of new forms of ammonoids collected mainly from a single locality - on the right bank of the Istyk River, from deposits of the Kuberganda Formation ...

There are almost no fossil remains of good preservation in the Jurassic marine sediments of the Upper Priamurye. However, the assembled collection makes it possible to describe some groups of fauna monographically. The present work describes the representatives of the genus Retroceramus collected in the Oshurkovskaya Formation. The age of this formation is established on the basis of the study of the whole complex of fauna collected in it and, first of all, belemnites as Middle Jurassic (Aalenian-Baiosian). The fauna described here was studied under the direction of V. I. Bodylevsky ...

The present paper summarizes the author's long-term study of the Jurassic and Cretaceous faunas of Novaya Zemlya. It is based both on literary sources, subjected here to critical revision, and on the collections made by many expeditions that visited Novaya Zemlya ....