No 3 (2024)

The Paleozoic section on the Kozhim River of the Subpolar Urals is the best sequence of the northern Urals. The border of Carboniferous-Permian deposits are observed on the opposite banks of the Kozhim River and are represented by two types of sections: on the right bank — the Kozhym skeletal mound, on the left bank — depression deposits of mixed composition (Losinoostrov Fm.). The article presents the first information on the isotopic composition of carbon and oxygen in the Lower Permian limestones of the Losinoostrov Fm. It is shown that the obtained data on the isotopic composition on the ä¹³C–ä¹⁸O diagram are visually separated into three clusters. The first cluster with the lowest values of ä¹³C (–0.3…1.1 ‰) and ä¹⁸O (23.5…25.0 ‰) included the most intensively silicified rocks (siliceous bioclastic limestones, secondary silicitolites, siliceous-carbonate- argillaceous mixtolites and siliceous- argillaceous limestone). The third cluster, with the highest values of ä¹³C (3.9…5.1 ‰) and ä¹⁸O (26.0…26.8 ‰), includes bioclastic and peloid-micritic limestones. In this case, the ä¹³С values correspond to the range of variations in the carbon isotopic composition indicated in review works on the chemostratigraphic correlation of Permian deposits. The second cluster occupies an intermediate position and is characterized by the values of ä¹³C (2.0…2.8 ‰) and ä¹⁸O (24.3…25.4 ‰). This cluster is predominantly represented by limestones enriched with terrigenous materials.

A comparison is made of the isotopic composition of the limestones of the Losinoostrov Formation with the coeval limestones of the Kozhim skeletal mound, which showed higher values of ä¹³C and ä¹⁸O in the latter.

This article completes the publication of the «Memories of Mineralogists» of the repressed Professor A. Ya. Mickey, found by the author in the Professor D. P. Grigoriev Archive, kept in the Russian Mineralogical Society. From the correspondence the motivations and life circumstances in which the texts were written become clear. A. Ya. Mickey’s letters are deciphered, attributed and briefly commented. The relevance of the article lies in the need to uphold the priorities of Russian science. The aim of the work is to cover as fully as possible the professional activities of repressed mineralogists as an important component of the history of Russian science. Mention of I. M. Beznarytny, A. K. Boldyrev, P. V. Bryantsev, V. I. Vernadsky, P. Groth, S. A. Zaborovsky, V. A. Zilbermints, L. L. Ivanov, E. P. Kastner, V. I. Kryzhanovsky, E. K. Lazarenko, N. I. Lebedev, A. V. Nechaev, I. I. Tanatar, V. V. Tikhomirov, E. K. Ustiev, N. M. Fedorovsky, G. K. Feldman, A. E. Fersman, P. N. Chirvinsky, and I. I. Shafranovsky should attract the attention of readers. Attention is drawn to the importance of personal archives in the study of the history of science. The of Professor D. P. Grigoriev Archive in letters and other documents reflects several decades of the pre-war and post-war history of Russian mineralogy.

The purpose of this study is to study the microstructure and 3D modeling of Paleoproterozoic stromatolites Segosia columnaris and Sundosia mira in the eastern part of the Fennoscandian shield (Karelian craton). The premise of the study is the extensive paleontological material collected by researchers in the 1950s and 1980s. Modern methods, including SEM analysis, 3D modeling, and the results of Raman spectroscopy are used. As a result of studying the microstructure of stromatolites, possible remnants of cyanobacteria involved in the formation of these structures were identified, which potentially indicated the biogenic origin of the studied samples. The results of Raman spectroscopy obtained by other authors also indicate the biogenic nature of the studied samples.

For the first time, images of the spatial shapes of the studied stromatolites were obtained by 3D visualization software, which could be used to refine the classification of stromatolites by morphological features. 3D modeling of stromatolite buildings allowed restoring their original shape.

Vasily Nikolaevich Filipov, Senior Researcher at the Laboratory of Experimental Mineralogy of the Institute of Geology FRC Komi SC UB RAS, died on March 3, 2024, at the age of 73. Vasily Nikolaevich was a highly qualified specialist who provided electron microscopic observations and microanalysis of minerals, artificial crystals and new materials at the most modern methodological level at the Institute of Geology. On the basis of V. N. Filippov’s researches complex problems of the genesis of a number of minerals — diamond, quartz, sphalerite, gold, fluorite — have been solved, and the ways for the rational use of various types of mineral raw materials of the Komi Republic have been outlined. He is the author of a number of inventions and discoveries in electron microscopy. He particularly discovered a new mode of operation of scanning electron microscopes, which significantly expanded possibilities of study of mineralogical objects, and a method for adjusting the position of the electron gun, a number of methods for metrological testing of the electron microscope was created. His original methods for preparing and mounting samples in an electron microscope are widely used in scientific laboratories and research centers in Russia. Vasily Nikolaevich was awarded the Certificate of Honor of the Ural Branch of the Russian Academy of Sciences (1998), the Certificate of Honor of the Trade Union of the Russian Academy of Sciences (1999), the Certificate of Honor from the Ministry of Natural Resources and Environmental Protection (2013) and the Certificate of Honor of the Komi Republic (2022), the Medal of the 2nd degree of the Order of Merit for the Fatherland (2002).