pdf № 339, March

DOI: 10.19110/geov.2023.3.1

We present a novel study of fluid inclusions in the vein quartz of the Kyvvozh gold placer field and in the quartz of gold-quartz intergrowths from the placer (methods of homogenization, cryometry, and Raman spectroscopy were used). We determined that in vein quartz the homogenization temperature of fluid inclusions fluctuated in the range of 220–425 °C, the liquid phase was represented by aqueous solutions, predominantly sodium and magnesium chloride. The homogenization temperature of fluid inclusions in quartz of gold–quartz intergrowths is 220–330 °C, and an aqueous solution of sodium chloride predominates in the liquid phase. Mineral formation proceeded in two stages: at the first stage, the fluid was enriched with nitrogen, at the second stage — with carbon dioxide.

Keywords: quartz, fluid inclusions, conditions for the formation, gold.

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DOI: 10.19110/geov.2023.3.2

The fauna of small mammals from two cave localities (Figurny and Ilych grottos) in the western slope of the Northern Urals (Komi Republic, Russia) was studied. The study of taxonomic composition and dental morphology of small mammals from the Figurny grotto revealed Late Glacial and Early Holocene assemblages. Late Glacial assemblages include tundra and tundra-steppe species (76–82 %), forest (15 %) and intrazonal (3–8 %) forms. Species composition indicates open spaces occupied by forest-tundra or forest-steppe vegetation with a relatively low snow cover in winter and also a cold, dry climate in the Late Glacial period. By the Early Holocene, due to the transformation of climate and composition of vegetation, in the communities of small herbivorous mammals, there was a change in the dominant species from tundra-steppe to forest (71 %). The share of tundra and tundra-steppe species was still relatively significant (up to 25 %).

Keywords: small mammals, steppe pika, collared lemming, narrow-headed vole, morphology of molars, Late Pleistocene, Late glacial, Holocene, Northern Urals, northeastern part of European Russia.

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DOI: 10.19110/geov.2023.3.3

The results of a palynological study of terrigenous rocks exposed in the lower reaches of the Vertny River and correlated with the Syninskaya Formation of the Bolshesyninskaya Series of the Legend of the North Ural Sheet Series GK-200/2 are presented. The Middle Triassic (Ladinian) age of the rocks was determined. A quantitative analysis of the species composition of the identified palynological assemblage using the Sporomorph EcoGroup method (SEG-analysis) was carried out. Based on palynological data, elements of the vegetation cover and landscape conditions have been reconstructed. It is concluded that the studied deposits were formed in the Ladinian Age in a very warm, humid climate within a vast tidal paleodelta. In the formation of the terrestrial vegetation cover, the leading role was played by moisture-loving plants characteristic of coastal marshes, deltaic lowlands, and tidal flats with mangrove-like thickets.

Keywords: spores and pollen, Syninskaya Formation, Middle Triassic, Ladinian, the Timan-Northern Urals region.

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DOI: 10.19110/geov.2023.3.4

This paper describes technologies for processing of oil shales and determines parameters of thermal decomposition without oxygen access (pyrolysis) and hydrometallurgical methods for extracting useful components. The following methods are presented: leaching to extract valuable components into a sulfuric acid solution, and selective extraction to ion-exchange resins by sorption of valuable components of vanadium and molybdenum. The presented methods are not implemented on an industrial scale, since there is no oil shale processing in the Republic. Perspective technological schemes of oil shale ash processing are analyzed. The process involves the addition of sodium chloride to the process of thermal decomposition without access to oxygen (pyrolysis). The resulting ash is leached in vats with sulfuric acid 160 g/l, at room temperature, T : W = 1 : 5, duration 60 minutes. The resulting metal-bearing sulfuric acid solution is filtered and sent to sorption and precipitation. Extraction of vanadium and molybdenum into solution is more than 60–70 %. It should be noted that with an increase in the consumption of sulfuric acid over 160 g/l, the concentration of metals in the productive solution does not increase. The ion-exchange resins of the English company PUROLITE were used to extract metals from the productive solutions of leaching of oil shale ash from the Aktau deposit: for the extraction of molybdenum — A-100 Mo grade, and vanadium — A-109 grade.

Keywords: Uzbekistan, metal-bearing oil shale, processing technology, vanadium, molybdenum.

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