The present paper shows elemental and carbon and strontium isotope composition of the Upper Kazanian (Middle Permian) stratotype section Pechishchi, Russia. A new version of Noinsky's cycles scheme ...has been obtained for Martinet and Sougy's Diagram types of carbonates, with the geochemical indices values changing within marine, evaporate and clastic beds. The δ13Ccarb values vary within interval 0 − +10‰ V-PDB with a mean value 6.2 ‰ V-PDB. The negative excursions of δ13Ccarb values (with amplitudes 2-8 ‰) are assigned as significant land-derived sedimentary inputs. The values of 87Sr/86Sr ratio in the data set of 17 samples change from 0.707267 to 0.707417 (mean value 0. 70734). On standard 87Sr/86Sr curve these values correspond to the interval 273 - 268 Ma.
Stratigraphic sequences are interrupted cyclic records. Only 5-10% of the stratigraphic record is preserved in continental sediments. The most of the sedimentary history is not recorded in the ...sections due to the lack of sedimentation or erosion of sediments. Therefore, the lithological data series on continental sections very often represent records of a random process. This paper analyses the spectra of grain size, carbonate content and magnetic susceptibility of three continental sections of the Middle-Upper Permian (the Monastery Ravine and the Kzyl Bairak outcrops on the Volga river bank, the Sheremetievka outcrop on the Kama river bank) to estimate a quantity and a quality of stratigraphic records.
This article overviews the results of a preliminary magnetic and mineralogical study of the bottom sediments of Lake Beloe (Southern Siberia, Russia). The magnetic and mineralogical properties of the ...sediments were examined. Their variations were correlated with geological factors. A comprehensive magnetic survey was performed: magnetic susceptibility of samples extracted from three sediment cores was measured; normal remanent magnetization in a continuously increasing external magnetic field of up to 1.5 T was calculated; differential thermomagnetic analysis was carried out based on induced magnetization and scanning electron microscopy (SEM) for certain samples. The magnetic component was divided into three subcomponents based on the normal magnetization curves: ferromagnetic, dia-/paramagnetic, and superparamagnetic. The contribution of each subcomponent to the total magnetization was determined. It was found that the magnetic susceptibility values correlate well across all the studied cores, thus making it possible to compare them. Magnetite and pyrite turned out to be the magnetic minerals distributed throughout almost the entire section. In the Day–Dunlop plot, the studied samples are represented by single-domain (SD) and pseudo–single-domain (PSD) grains. The magnetic components vary consistently along the section, suggesting that the depositional environment underwent substantial changes. Particles similar in composition and morphology to cosmogenic and volcanic spherules were discovered using the SEM method. Based on the obtained results, the boundary between the Pleistocene and Holocene deposits was defined.
Porosity is known as one of the main properties of reservoir rocks. The exact value of this parameter is difficult to measure. In present paper it is proposed using MultiSpec processing technique as ...cost-effective alternative method for estimating 2D-porosity from thin sections images of carbonate rocks on base of core samples picked out from carbonate reservoir rocks of Tournasian age in well, situated on southern slope of South-Tatarian Arch (Volga-Ural region, Russia).
The Siberian Traps volcanism is widely considered the main cause of the end-Permian mass extinction, the greatest biological crisis in the Earth history. While the extinction is interpreted as ...catastrophic and sudden with estimates of duration of approximately 35–40 thousand years from marine strata in South China, various lines of evidence have emerged for a more complex, prolonged, and diachronous extinction pattern. We present here the results of a multidisciplinary study of the Permian-Triassic continental transition in the Kuznetsk Basin, Russia. The region is proximal to the Siberian Traps LIP and the detrimental effects of the flood basalt volcanism in the Kuznetsk Basin may have been of similar scale as in the main area of the Siberian Traps distribution (Tunguska and Taymyr regions). Whereas earlier work has placed the Permian-Triassic boundary position between the coal-bearing Tailugan Formation and the volcanoclastic Maltsev Formation, here we revised the traditional model using three independent methods: radioisotopic CA-IDTIMS U-Pb zircon ages, δ13Corg isotope values and paleomagnetic proxies. The regional extinction of the humid-dominated forest flora (cordaites) and the aridity-induced biotic turnover in the Kuznetsk Basin occurred 820 kyr earlier than the end-Permian extinction event recorded in South China at 251.94 Ma. The biota in Kuznetsk Basin at the turnover subsequently diversified (with some exceptions) across the Permian-Triassic transition.
By compiling a large taxonomic database, we find that marine and terrestrial biotic diversity in Siberia progressively increased from the beginning of the Permian up to the middle Roadian (early Guadalupian global glacial event). After that time, the diversity at the species and generic level progressively and slowly declined towards the aforementioned latest Changhsingian (252.76 Ma) biotic turnover. Starting from this time, the biota rapidly diversified in the latest Changhsingian and Early-Middle Triassic. We suggest that the Permian-Triassic mass extinction mostly occurred in the tropics and subtropics due to the strong climatic warming, which was relatively low in late Changhsingian and gradually but quickly extends in the latest Changhsingian to an abnormally high temperature and extremely low oxygenated water in the oceans that was deadly for most marine animals. The warm climate shift poleward during Permian-Triassic transition in the middle-high latitudes caused the replacement (turnover) of the humid-related biotas by the dry climate-related and more diverse communities, which continued to expand throughout the Triassic in both marine and terrestrial habitats. The pattern of the Permian-Triassic event in both marine and terrestrial habitats was more intricate in terms of extinction, turnover, and diversity of biota within the different climatic zones and environmental habitats than has been generally considered.
•Permian-Triassic transition in Kuznetsk Basin (Russia) constrained with CA-IDTIMS dates.•Regional biota evolutionary turnover in the region occurs 820 kyr earlier than in South China.•The biota in Kuznetsk Basin diversified across the Permian-Triassic transition.•Permian-Triassic extinction mostly occurs in the tropics due to the strong climatic warming.•Siberian basalts as a cause of the extinction at the P-T boundary remain questionable.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The present paper shows the thermal features of the treatment on the reservoir, geochemistry of sediments, and intensity of chemical weathering of terrigenous rocks of the Ufimian-Kazanian natural ...reservoir of the section of Karkali in the basin of the r. Sheshma and r. Inesh, to predict the efficiency forecast of the application of heat-treat at the object and decipher the genesis of sedimentary formations in the area. Changes in the main elements in rocks are represented in the variation diagram.
This article reports on some preliminary findings of a study on the seismoacoustic profiling of the basin of Lake Turgoyak (Southern Urals) and the magnetic properties of its bottom sediments. In the ...eastern depressions, the lake sediments are up to 8 m thick. The radiocarbon dating of the sediment samples suggests that the lake is at least 25 000 years old. The seismoacoustic data reveal that the lower part of the section, which is composed of the dense Neopleistocene sediments, accumulated when the water level was lower. The Holocene sediments are poorly consolidated silts up to 4 m thick. The magnetic properties of the sediments were found to be indicative of the environmental conditions and fluctuations in the lake level. The high-amplitude variations in the scalar magnetic values of the sediments point to frequent changes in the sedimentation conditions. The sediments with the highest magnetic susceptibility (χ), natural remanent magnetization (
NRM
), coercive force (
B
c
), coercivity of remanence (
B
cr
), saturation magnetization (
M
s)
, and magnetization remanence (
M
rs) are likely to have formed during the periods when sedimentary material was transported by ice, often with a significant influence from wind.
The formation of a modern generation of engineers capable to drive changes that meet the requirements of the future necessitates a new approach in pedagogical training of engineering teachers. The ...international ENTER (
E
ngineeri
N
g educa
T
ors p
E
dagogical t
R
aining) project is being developed as part of EU Erasmus program focused on addressing the actual education needs from the standpoint of human and social capitals development both in Europe and in other countries. The ENTER project is aimed at the creation and development of an international platform for multilevel vocational training/retraining of technical universities teachers on the basis of the Eurasian interaction network. Surveys among employers, teachers, and engineering university students, as well as scientific periodicals analysis allowed us to determine the complex of universal and specific engineering and pedagogical competencies that educators should master not only for today, but also for the future needs. Based on the competency analysis, a three-level modular teacher training/retraining program (iPET program) has been developed and its international accreditation is planned.
Research subject. Bottom sediments of Lake Bannoe (Southern Urals). Aim. Identification of lithologic features of Lake Bannoe sediments, which could reflect sedimentation conditions in the Holocene. ...Materials and methods. The detailed complex analysis included radiocarbon dating, grain-size analysis, X-ray diffraction analysis, electron microscopy, X-ray fluorescence and isotope analysis, coercive spectrometry and pollen analysis. Results. Radiocarbon dating showed that sedimentation in Lake Bannoe began no later than ~13 thousand years ago. Combination of data from various laboratory studies unraveled four lithological zones and the corresponding stages in the sedimentation history. The grain size, allothigenic particles, carbonate minerals, organic matter and isotopic composition of carbon and oxygen are the most informative indicators. Grain size variations and the ratio between allothigenic and carbonate components reflect changes in the Lake’s depth and clastic material supply, which, in turn, is associated with humidity. Organic matter parameters (TOC, δ13Corg, C/N ratio) can be considered as indicators of climate-sensitive changes in bioproductivity of the sedimentation basin. They also reflect the ratio of exogenous and endogenous organic matter in the sedimentary environment. The isotopic composition of carbon and oxygen (δ13Ccarb, δ18Ocarb) in sedimentary carbonates is an informative indicator of lithological zones and climatic events of the Holocene due to its sensitivity to changes in biomass, temperature fluctuations, and fresh water inflow. The paramagnetic component k_para was used as an indicator of the allothigenic material input into the lake basin for the first time in this region. Conclusions. The granulometric, mineral, and chemical composition, as well as the magnetic properties of Lake Bannoe sediments reflect the history of Lake sedimentation in the Southern Urals, which agrees mainly with the climate stages of the Holocene.
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