Deinocephalians of the U.S.S.R.

The deinocephalian pelvic girdle, of general pelycosaurian structure, is useful in systematic diagnosis. In primitive Russian deinocephalians, two contrasting pelvic patterns are recognized, one light, thin-walled, narrow, and of V-shaped cross-section, and the other massive, thick-walled, wide, and of U-shaped cross-section. The former is characteristic of two families of lightly- built, mobile land carnivores, the Eotitanosuchidae and the Brithopodidae. The Eotitanosuchidae are more primitive and pelycosaur-like, while the Brithopodidae show more variation, and specializations of large size, shallower acetabulum (related to mobility?), and re-enforcement of a weak pubic symphysis by additional processes. The massive type of pelvis characterizes large, heavily built herbivorous animals of the family Estemmenosuchidae. In general pelvic structure, the Estemmenosuchidae resemble the South African anteosaurs and tapinocephalians and the Russian tapinocephalians. In detail, however, they show a more primitive stage of evolution, overlaid by characteristic specializations which relate them more closely to the advanced Russian forms than to those of South Africa. Three new genera are erected, Biarmosaurus, fam. Eotitanosuchidae; Chthomaloporus, fam. Brithopodidae; and Molybdopygus, fam. Estemmenosuchidae. One specimen formerly referred to Deuterosaurus Yefremov 1954, and five formerly included in the type of Brithopus Yefremov 1954 are referred to Molybdopygus. The more primitive deinocephalians are from Yezhovo in the Ocher District, Perm Province, while more advanced forms are from Isheyevo, in Tataria, where-therocephalians and other South African elements are also found. It is therefore concluded that the Ochersk beds are older than those of Isheyevo and must be dated to zone I of Yefremov's system. — N. Hotton III.     

Eozoic complexes of the U.S.S.R.

Soviet geologists consider the Precambrian to be divided into two groups — Archaean and Proterozoic; but such a division is unsatisfactory. A major unconformity separates Proterozoic volcanic and sedimentary formations from an underlying sequence that contains two supergroups of supercrustal formations. The oldest of these is unanimously considered to be Archaean. Rocks of that supergroup play an essential part in the composition of the Baltic, Ukrainian, Aldan and Anabar Shields and of the ancient fold belts of the East-European and Siberian platforms.Distinctive features in the composition, tectonic structure, metamorphism and metallogeny of Archaean complexes lead to the conclusion that they were formed in specifically mobile areas, different from geosynclinal areas.The other supergroup of high-grade metamorphic rocks has no clear place in the accepted two-fold stratigraphic scheme of the Precambrian, and it is considered sometimes to be Archaean and sometimes to be Early Proterozoic. We propose restoring the forgotten name “Eozoic” for that supergroup. Eozoic complexes are characterized by peculiarities of composition and inner structure, which signify changes in the tectonic regime of the earth at the lower and upper boundaries of the Eozoic Supergroup. These peculiarities give grounds for distinguishing the Eozoic Supergroup as an independent stratigraphic division.The Stanovoy Complex of the southern part of the Aldan Shield is a stratotype for the Eozoic Supergroup. Many well-known stratigraphic subdivisions of the Siberian Platform (e.g., the Eniseiskaya, the Birusinskaya series and others), the Taratash Complex of the Urals, the Goranskaya and Shahdarinskaya series of the South-West Pamir, the Tikitch complex and Aulskaya series of the Ukrainian Shield, and in part the Belomorsky Complex of the Baltic Shield, as well as some others, are also Eozoic.The Eozoic complexes are characterized by the following specific features: only some supercrustal formations are typical for them; the small number of rock types which have a total thickness about 5–6 km; relatively monotonous mineral composition of the rocks; variable quantitative ratios of rocks; absence of contrasting marker beds; regional metamorphism and ultrametamorphism in the amphibolite facies; wide development of ultrametamorphic granitoids and migmatites; distinct tectonic differentiations of the basin of sedimentation.Dates determined by isotopic analyses, which mostly reflect the metamorphism of the deposits, fall predominantly in the range 2600–3100 Ma.     

Precambrian tillite rocks of U.S.S.R.

Detailed regional studies and the author' personal observations on tillite-like rocks in Siberia and Ural suggest that pseudo-tillites, only too common in subaqueous landslide formations, were often mistaken for tillites or tillite-like rocks, because of their resemblance to fossil moraines. --V. P. Sokoloff.     

In remembrance of Prof. PhD Dr. h.c. Wolfgang H. Berger

International Journal of Earth Sciences -     

Development of geological research in U.S.S.R Academy of Sciences and U.S.S.R. Ministry of Geology and Mineral Reserves

On October 12, 1962, a joint session of the Presidium of the U.S.S.R. Academy of Sciences and the Collegium of the U.S.S.R. Ministry of Geology and Mineral Reserves adopted a resolution “On the present state of the geological sciences in the U.S.S.R. Academy of Sciences and the U. S. S. R. Ministry of Geology and Mineral Reserves and their prospects for the future.” Important contributions of Russian geologists are acknowledged, but attention is drawn to many shortcomings. Future goals of geological study and work are given in detail. Twenty-one lines of research to be concentrated on are given, covering all phases of geology, geophysics, and geochemistry. In discussing the failings of the geological profession in Russia, it is of interest to note the following comment: “Geological research in other countries is still insufficiently studied and applied, and we are not making adequate use of geologic information from abroad.” The list of the Russian geologists' shortcomings sounds vaguely familiar. —J. R. Hayes     

Geologic factors of distribution of mineral deposits in eastern U.S.S.R.

The Pacific Mobile belt is differentiated into an outer (continental) zone of predominantly Mesozoic folding (Verkhoyansk -Chukotka, Mongolo-Okhotsk, and Sikhote-Alin folded provinces) and an inner oceanic zone of Cenozoic folding, adjacent to mobile provinces of the "island arc" type (Sakhalin, the Kuriles, Kamchatka). These zones are separated by the East-Asian volcanic belt associated with a fault system which cuts off the older Mesozoic Verkhoyansk-Chukotka and Sikhote- Alin structures. Two important mineralization epochs are evident - Sino-Cambrian and late Mesozoic- Cenozoic. The Mesozoic-Cenozoic mineralization epoch exhibits a definite tendency for “rejuvenation” of the mineralization processes, going away from the continent and toward the Pacific trough, from late Jurassic in the eastern Trans-Baykal region and parts of the northeast to Neogene in the province of the Okhotsk geosynclines. An outstanding feature of endogeneous mineralization in this region is the linear arrangement of the ore zones determined by a system of major magma-controlling and other faults.—C. E. Sears     

The selenium content of U.S.G.S. standard rocks

Selenium was determined in duplicate portions from three bottles of six U.S.G.S. standard rocks by a spect rofluorimetric procedure. The following averages, as p.p.m. Se, were obtained: PCC-1, 0.031; GSP-1, 0.088; BCR-1, 0.12; SCo-1, 0.91; MAG-1, 1.3; and SGR-1, 3.7. One-way analysis of variance of the several sets of data showed no significant differences in the selenium content among bottles of any specific rock; these samples may be accepted as homogeneous for their selenium contents by this analytical method.     

Distribution of regional metamorphism fades in U.S.S.R.

A detailed classification of regional metamorphic rock facies is presented along with the results of compiling a small scale Map of Metamorphic Facies of U.S.S.R. It is demonstrated that typical metamorphic complexes are associated with certain large structural elements of the crust. The aspects of metamorphism are used in identifying the areas of ancient platforms, two types of mobile belts, and two types of high pressure zones at the junction of major structures of different degrees of stability.—Author     

Crustal investigations of the U.S.S.R. by means of earthquake-generated converted waves

The method of earthquake-generated converted waves which is based on the simultaneous recording of longitudinal (P), transverse (S) and converted (PS and SP) waves has been used in the U.S.S.R. since 1956. Converted phases generated at crustal and upper-mantle discontinuities in the seismic focal area are carefully analyzed. In this paper some dynamic characteristics of transmitted PS- and SP-waves arising at different types of boundaries are described.

From a comparison of the properties of the recorded converted waves with the results of theoretical computations conclusions can be drawn with regard to the possible structure of the “exchange” (conversion) boundaries. Seismic cross-sections are presented which illustrate the high effectiveness of the method in regional investigations of crustal structure. Owing to its significance and the multitude of observations (over 22,000 km of observation lines) the method is one of the principal seismic techniques used in the U.S.S.R. which give quantitative information on crustal layering.     

X-Ray Fluorescence Determination of Trace Elements in 6 B.C.S. and 5 P.R.E. Reference Materials

The concentrations of 20 trace elements in 6 British Chemical Standards (BCS) reference materials and 5 European Federation of Refractories Producers (PRE) reference materials have been determined by X-ray fluorescence spectrometry.     

A new occurrence of Permian Seymouriamorphs in the U.S.S.R.

A large number of specimens of Seymouriamorph amphibian, family Discosauriscidae, were collected from the south slopes of the Kuramanskiy Khrebet, Mt. Sarytaypan, 10 km northeast of the settlement of Adrasman, Tadzhik S.S.R. Deposits yielding the fossils consist of about 70 m of effusive sedimentary rocks, the top third being tuffs, tuff sandstones, and tuff breccias, and the remainder being alternating fine-grained sandstones, argillites, and siltstones, of gray, greenish, pink, and black colors. The beds overlie 800 m of tuff lavas and tuff breccias and are overlain by 200 m of-tuff breccias. Fossil leaves are abundant in the lower half of the beds in all lithologic types, but the vertebrates are confined to about 1 m of adjoining layers of fine-grained gray to pink sandstone, and almost black argillite. The fossils consist of complete impressions of skeletons, which will yield much anatomical information. Two genera are represented, the most abundant referrable to the Central European form Discosauriscus. The other is related to the European Leptoverpeton but may be new. These specimens permit correlation of the Sarytaypan deposits with Lower Permian' bedsgqn Czechoslovakia and Germany. Larval forms are by far the most abundant, but the presence of adults affords a reliable comparison of growth stages. New and detailed information of the development of the spinal column will also be forthcoming from further study of the growth stages. Presence of gills in the larvae reaffirms the persistence of an aquatic larval stage in the morphologically reptile-like Seymouriamorpha. — N. Hotton III.     

Some patterns of abyssal structure in the U.S.S.R.

Analysis of blocks and linear sutures in the base of the Russian Platform shows significant variations in their tectonic activities in different stages of the platformal evolution. --AGI Staff.