Reservoirs in carbonates of the lower oil and gas-bearing complex of the Timan-Pechora Province (for the anniversary of T. V. Maydl)

The paper presents Tatyana V. Maydl’s researches of formation and patterns of distribution of natural reservoirs in carbonate deposits of the Timan-Pechora oil and gas province. Tatyana Viktorovna Maydl is a recognized specialist in oil and gas geology. Her significant contribution to the development of the theoretical base of formation of carbonate deposits in the region, reconstruction of sedimentation conditions, finding degree of influence of secondary transformations on the reservoir and filtration properties of carbonate rocks, development of the basis for geological models of carbonate reservoirs, are analyzed. In the field of studying the morphology of the void space in low-capacity carbonate reservoirs, T. V. Maydl found that in the Lower Silurian dolomites with a shadow biohermal structure had the best filtration features, and in the Upper Silurian — bioclastic limestones. The main volume of the void space in the first type is associated with caverns and cracks, in the second — with matrix porosity. We showed that the results of T. V. Maydl’s work were not only of theoretical, but also of practical importance.

Woman-scientist, paleontologist

The article is devoted to the scientific activities of one of the first Russian women geologists, paleontologists — Tatyana Alekseevna Dobrolyubova in connection with the anniversary date — the 130th birthday anniversary. A whole stage in the history of geological studies of the natural resources of the Northern Urals, as well as paleontological studies of the Carboniferous and Permian corals of the Russian Platform and the Urals, are associated with her name. The most important directions of her research and the most significant achievements, as well as the stages of her life, are briefly highlighted.

First find of a potentially new mineral, Na-dominant at M 2-site eudialyte analogue: crystal structure and significance as a marker of ultraagpaitic environment

A potentially new mineral, M2Na-dominant analogue of eudialyte from the Khibiny alkaline massif, was investigated using the methods of electron probe microanalysis, X-ray diffraction, and IR spectroscopy. The crystal structure was refined to R = 5.7% in the anisotropic approximation of atomic displacements using 2577 independent reflections with F > 3(F). The unit-cell parameters are: a = 14.277(1), c = 30.400(1) Å, V = 5328.7(1) Å3; the space group is R-3m. The idealized formula of the mineral is (Z = 3): Na14Ca6Zr3[Na2(Fe,Mn)][Si26O72](OH)2(H2O1.0Cl0.6S2-0.5)(OH,H2O)2.5. Distribution of cations in the M2 micro-region is established: Fe in the flat-square coordination, Mn in the square pyramid and Na in the seven-vertex polyhedron. A comparative analysis of crystal chemical features of eudialyte М2Na-analogue samples from the Khibiny-Lovozero alkaline complex and Ilimaussaq alkaline pluton, Greenland is given. The mechanism of blocky isomorphism with the replacement of IVFe2+ with VIINa in the M2 micro-region is discussed. IR spectra of the М2Na-dominant eudialyte analogue are given: essentially hydrated sample (Na,H3O,H2O)15Ca6Zr3[Na2Fe][Si26O72](OH)2Cl∙2H2O from Ilimaussaq, less hydrated М2Zr-bearing sample (Na,H3O)13(Ca4Mn2)Zr3(Na2Zr)[Si26O72](OH)2Cl∙H2O from Lovozero and low-hydrated sample Na14Ca6Zr3[Na2(Fe,Mn)][Si26O72](OH)2Cl(OH,H2O)3 from Khibiny studied in this work.

Palynological asemblage of the Synya Formation (Middle Triassic) from outcrops at the Kydz'rasyu River, Bol’shaya Synya Depression, the Timan-Northern Urals region

The results of palynological study of the Synya Formation (Middle Triassic) in outcrops along the Kydz'rasyu River banks are presented. The published and archival results of previous palynological investigations of the Synya deposits were used as an additional record. It was shown that the species composition of the palynological assemblage (PA) of the Synya Formation on the Kydz'rasyu River fully corresponded to the PA Converrucosisporites conferteornatus — Florinites pseudostriatus and determined the Triassic, Ladinian, age of the enclosing deposits. The results of reconstruction of the growing vegetation testified to the existence of rich and diverse vegetation in the Ladinian Age on the studied territory, where the flora of highly moistened biotopes prevailed.

Origin of large diamonds in kimberlite

The evidence of the existence and fractionation of the global magmatic ocean on the Earth allows us to distinguish two stages of the formation of diamonds of increased size. The largest giant diamonds arose at an early stage of crystallization and fractionation of the peridotite layer of the magmatic ocean, since its bottom layer at that time was blocked by still hot upper ones and therefore cooled and crystallized very slowly and long. The mafic composition of this layer and the low viscosity of its magmas caused mainly octahedral cutting of the formed giant diamonds. Later crystallized mainly rhombododecahedral diamonds have increased coarseness due to the formation mainly by the growth of early octahedral crystals.

Specific features of sandstones of Upper Devonian Tayokuyakhinskaya Formation on southeastern slope of the Kanin Kamen range (Kanin Peninsula)

The results of studying the lithological and geochemical characteristics of sandstones of the Upper Devonian Tayaokuyakhinskaya Formation in the southeastern part of the Kanin Nos Peninsula are presented. The accumulation of sandstones of the Tayaokuyakhinskaya Formation occurred in the absence of volcanic activity in a shallow basin with small periodic fluctuations in sea level, which led to a change in the degree of maturity, sorting, and the ratio of clay and sandy components in the rock. The accumulation of the psammitic strata occurred due to the destruction and redeposition of weakly weathered sedimentary rocks in a moderately warm climate. It was established that the formation of the composition of sandstones was influenced by at least two sources of clastic material — garnet-bearing crystalline shales and feldspar-quartz sandstones metamorphosed into the greenschist facies. The latter, most likely, were the source of the indicative gold contents found in the Devonian clastic rocks.

The mesolithic Baigara human: mineralogical-geochemical studies, paleoecological reconstructions and history of early human migrations to Western Siberia

A modern human bone of the Mesolithic age, found for the first time in Western Siberia, was studied by the number of mineralogical-geochemical methods. Based on the results obtained, the conclusions about paleoecology, food types, and history of human migrations in the Late Pleistocene — Holocene in Siberia presented

First results of complex studies of modern microorganisms by physico-chemical and mineral-geochemical methods

We studied 14 samples of gram-negative and gram-positive bacteria, unicellular yeasts and green algae using optical, atomic force and analytical scanning electron microscopy, thermal analysis, gas chromatography, infrared spectroscopy, inductively coupled plasma mass spectrometry and isotope mass spectrometry. In shape, the cells of microorganisms vary from rod-shaped to lenticular and coccoid, in size they range from mesonanometer to micrometer. A strong positive correlation was found between the extreme cell sizes. An admixture of inorganic chemical elements — Mg, Ca, Ba, Na, K, Cu, Zn, P, S, Cl and submicron-sized precipitates of mineral phases — carbonates, phosphate sulfates, hydrogen sulfate phosphates, hydrogen phosphates, halite, kaolinite, was found in the chemical composition of the studied microorganisms, metal alloys of brass composition, baddeleyite. Among the 45 microelements identified in microorganisms, there were 7 essential elements (E), 17 physiogenically active (FA) and 19 abiotic (AB). The total concentration of trace elements ranged from 0.003—0.26 wt. %. The value of the essential coefficient — E / AB — averaged 196 ± 153. Microorganisms were characterized by a mixed fat-protein elemental composition, they contained 14 amino acids belonging to the aliphatic, aromatic, basic, acidic, hydroxyl, imino and sulfur-containing groups. The total amino acid content ranged from 409 to 942 (682 ± 221) mg/g. Up to half of the amino acids were represented by the left (L) and right (D) enantiomers. The degree of racemization (D / L) ranged from 0.01 to 0.37. Yeast and chlorella were characterized by the most isotopically heavy composition of carbon in combination with relatively isotopically light nitrogen. In bacteria, a statistically lighter carbon was found in combination with a much heavier nitrogen. According to a number of properties — the chemical composition of organic matter, microelements, the degree of enrichment with antibiotic elements, the content of amino acids and the degree of their racemization — gram-negative and gram-positive bacteria differed. In general, the studied biological microorganisms were fundamentally different from the abiogenic organic substances found in meteorites and products of modern volcanism regarding their elemental and amino acid composition, carbon and nitrogen isotopes.

Lithogeochemical characteristics of metasandstones of the Chetlas series (Chetlassky Kamen, Middle Timan)

The lithological and geochemical features of the metasandstones of the Svetlinskaya and Vizingskaya formations of the Middle Late Riphean Chetlas series in the Middle Timan, which are a substrate of rare-metal-rare-earth mineralization in several ore occurrences of the Kosyus ore cluster, have been investigated. The interpretation of the results of traditional weight chemical and mass spectrometric inductively coupled plasma (ICP MS) analyses allowed us to identify differences in the material composition of metapesanics, mainly due to changes in the degree of sedimentation maturity of terrigenous material coming from the demolition areas. The composition of metasandstones in various ratios includes both weakly weathered products of destruction of volcanic rocks of intermediate/basic composition, and altered, including under conditions of the weathering crust, metaterrigenous formations. The accumulation of sediments took place in a shallow coastal-marine environment with changing hydrodynamics, which affected the rate of destruction of rocks in paleo-catchments.

Technological mineralogy: from Academician V. M. Severgin to the present day

It is shown that the origins of technological mineralogy in Russia are associated with the name of Academician V. M. Severgin, who at the end of the 18th century introduced the concept of «technological and economic» mineralogy. The stage of development of 1921—1955 is considered as important for the formation of the school of applied mineralogy. The next stage is the implementation of the principles of technological mineralogy in the practice of geological exploration and mining production and the creation of the Technological Mineralogy Commission of the All-Union Mineralogical Society by the beginning of 1983. The main directions of the development of technological mineralogy and the role of the published works of the commission are substantiated.