Russian Geology and Geophysics最新文献

{"title":"Two-Stage Model of Devonian Basic Magmatism in the Vilyui Paleorift (Siberian Platform)","authors":"O. Polyansky, V. Simonov, O.V. Koroleva, A. V. Prokopiev, A. Babichev, A. Kotlyarov, A. N. Semenov","doi":"10.2113/rgg20234666","DOIUrl":"https://doi.org/10.2113/rgg20234666","url":null,"abstract":"\u0000 —We report study results of basic intrusive bodies in the middle Paleozoic Vilyui paleorift (eastern Siberian Platform). Geochemical data for basic sills penetrated by boreholes in the rift’s dike swarms are presented, as well as our data on the time of formation of sills and dikes. We also studied mineral-hosted melt inclusions from a dolerite dike of the Vilyui–Markha dike swarm on the northwestern flank of the Vilyui paleorift. Data on the compositions of homogenous glasses of mineral-hosted melt inclusions yielded the P–T parameters of mantle sources of basic melts responsible for the formation of the Vilyui paleorift gabbro-dolerites. Two depth levels of basic melt generation have been established: 95–65 km at 1480–1400 °C and 55–45 km at 1360–1320 °C. Crystallization of the melts occurred at a shallow depth of 12–4 km with a decrease in temperature from 1185 to 1125 ºС. This occurrence of basic melt sources at two different depths, as well as the heterogeneity of the chemical composition of melt inclusions and their host minerals explains the presence of two pulses of Devonian basic magmatism. Our new numerical thermomechanical model of magma rise during melting of the lithospheric mantle above a mantle plume supports the existence of two chambers at the spinel–garnet peridotite boundary and under the base of the crust, as well as the two-stage nature of Devonian magmatism.","PeriodicalId":506591,"journal":{"name":"Russian Geology and Geophysics","volume":"189 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140222600","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Paleomagnetism of the Abinskaya Group of the Kuznetsk Depression (southern Siberia) – Implications for the Evolution of the Siberian Large Igneous Province at the Permian–Triassic Boundary","authors":"A.A. Eliseev, D. Metelkin, V. Abashev, N. Mikhaltsov, E. Vinogradov, V. Bragin","doi":"10.2113/rgg20234692","DOIUrl":"https://doi.org/10.2113/rgg20234692","url":null,"abstract":"\u0000 —We report results of a systematic paleomagnetic study of the Abinskaya Group of the Kuznetsk depression, including a typical volcanic complex that reflects important features of the evolution of the Permian–Triassic Siberian large igneous province (LIP). Four zones of magnetic polarity have been established in the group’s deposits. We revise the correlation of the volcanic sheets of the Mal’tsevo Formation (Fm.) at the base of the group with the Ivakinsky Fm. of the Norilsk region, which is linked to the initiation of trap magmatism. The beginning of the eruption of the Saltymak complex volcanic rocks in the Kuznetsk area corresponds to the boundary between subchrons LT1n.1n and LT1n.1r (251.2 Ma) within the Kedrovka sub-formation of the Mal’tsevo Fm. This boundary was traced in the magnetostratigraphic sections of the Maimecha-Kotui, Koltogor-Urengoy, Western Taimyr, and Norilsk regions of the Siberian LIP and suggests a correlation of the Mal’tsevo Fm. volcanic rocks with the upper part of the undifferentiated interval of the Onkuchak – Tyvankit (?) fms., the base of the Korotchaev Fm., the Verkhnetam Fm. and the top of the Samoed Fm. The duration of this main pulse of volcanism in the Kuznetsk depression did not exceed 0.1 Myr. The volcanic sheets of the second, significantly weaker pulse of the Yamin Fm. are compared with the Maimecha Fm. of the Maimecha-Kotui area and the top of the Korotchaev Fm. of the Koltogor-Urengoy area. Thus, the accumulation of the entire Abinskaya Group, including the sedimentary complex of the Sosnovka Fm., lasted no more than 1.5 Myr. Except for the initial stage, this coincided with the eruption of most of the Maimecha-Kotui and Koltogor-Urengoy trap sections. The early magmatism of the Ivakinsky time and its analogs in other areas of the Siberian province during the Permian–Triassic boundary in the Kuznetsk depression probably corresponds to the break between the Taylugan Fm. and the Abinskaya Group. The mean paleomagnetic pole (PLat = 59.0°, PLon = 160.3°, A95 = 5.7°, N = 33) calculated for the entire studied section reflects the paleogeography of the Kuznetsk depression and can be considered a reference pole for the Permian–Triassic boundary.","PeriodicalId":506591,"journal":{"name":"Russian Geology and Geophysics","volume":"3 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140229440","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Algorithm for Surface Wave Suppression on 2D Seismic Data Using the Slant Karhunen–Loeve Transform in a Time-Frequency Domain","authors":"A. Yablokov, M.V. Moiseev, A. Serdyukov, D.A. Litvichenko","doi":"10.2113/rgg20234660","DOIUrl":"https://doi.org/10.2113/rgg20234660","url":null,"abstract":"\u0000 —Surface waves are the main source of coherent noise in land seismic survey, and their suppression is one of the main stages of common depth point data processing designed to improve the quality of tracking primary reflections on time sections. In practice, noise reduction is carried out using procedures from modern software based on numerical modeling of waveforms. However, they are too resource-intensive and have a large number of subjectively customizable parameters. The known algorithms have a common drawback: either the energy of reflected waves is distorted in an interference zone with a noise wave or the noise suppression quality is unsatisfactory. The current research is aimed at improving the filtering algorithm in a time-frequency domain using the slant Karhunen–Loeve transform in order to overcome these limitations, to increase the accuracy and rate of its software implementation, and also to test it when processing profile field data from land-based 2D seismic surveys. The algorithm is modified by developing a new method for determining static corrections for surface wave hodograph rectification in a time-frequency domain and by the application of preprocessing in which the reflected wave signal is removed preliminarily. These and other modifications ensure faster calculations and improve the quality of surface wave interference suppression. In addition, the slant Karhunen–Loeve transform is accelerated by parallelizing calculations across logical processor cores. In this paper, the algorithm is described in detail, its significant advantage over the standard methods of bandpass filtering and F–K filtering is shown, and the results of processing the field data obtained by the SWANA procedure (Geovation 2.0) and by the slant Karhunen–Loeve transform. The result obtained by the slant Karhunen–Loeve transform is superior to the SWANA procedure in terms of the surface wave filtering quality and has only four adjustable parameters (SWANA has 20 parameters)","PeriodicalId":506591,"journal":{"name":"Russian Geology and Geophysics","volume":"60 5","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140230264","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Upper Jurassic Sediments in the Western Side of the Frolovskoye Basin in West Siberia: Diverse Patterns and Environments of Deposition","authors":"V. Nemova, A. S. Shakhov, T.A. Bazhukova, A.M. Isangulova, O.O. Kim, A.D. Skomorokhova","doi":"10.2113/rgg20234683","DOIUrl":"https://doi.org/10.2113/rgg20234683","url":null,"abstract":"\u0000 —The paper presents data on different types of Late Jurassic carbonaceous–siliceous–shale sequences of marine deposits in the western side of the Frolovskoye basin. The diverse sedimentation patterns in the area were presumably controlled by tectonics, sea bottom topography, and currents, with voluminous gas venting through large faults. Recent exploration drilling in the Elizarovo trough and the Vygnlor basin revealed Upper Jurassic sections of a previously unknown type with low-radioactivity lower strata markedly thicker at the account of biogenic radiolarite intercalations affected by postdepositional carbonatization. The lithology of these rocks is described with implications for deposition environments and extent of such sections.","PeriodicalId":506591,"journal":{"name":"Russian Geology and Geophysics","volume":"58 15","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140231033","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fuzzy Logic-Based Landslide Susceptibility Mapping in Earthquake-Prone Areas: A Case Study of the Mila Basin, Algeria","authors":"W. Chettah, S. Mezhoud, M. Baadeche, R. Hadji","doi":"10.2113/rgg20244699","DOIUrl":"https://doi.org/10.2113/rgg20244699","url":null,"abstract":"\u0000 —This research focuses on analyzing landslides triggered by a moderate earthquake (Mw = 4.9) in the northeastern region of the Mila province, which resulted in significant damage and economic losses in the El Kherba district and Grarem Gouga city. Through an extensive field-based investigation, a comprehensive inventory of landslides has been compiled. To assess the susceptibility to landslides triggered by seismic activity, a GIS-based fuzzy logic model was employed. The model incorporates various input factors, such as lithology, slope angle, normalized difference vegetation index (NDVI), distance from rivers and roads, precipitation, and seismic hazard, which is shown on a map. The study compares the performance of different fuzzy operators and gamma values and determines that using fuzzy gamma operators with a gamma value of 0.8 yields a satisfactory consistency with the distribution of landslides. Moreover, incorporating the map of seismic hazard as a causative factor enhances the accuracy of landslide susceptibility mapping. This study underscores the utility of the fuzzy logic model in disaster management and the planning of development activities.","PeriodicalId":506591,"journal":{"name":"Russian Geology and Geophysics","volume":"18 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140242878","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ratios of Sulfur Isotopes (32S, 33S, 34S, and 36S) in Archean Rocks of Karelia: Evidence of Microbial Life and the Anoxic Atmosphere","authors":"T. Velivetskaya, A. Ignatiev, S. Vysotskiy, A. Aseeva","doi":"10.2113/rgg20234602","DOIUrl":"https://doi.org/10.2113/rgg20234602","url":null,"abstract":"\u0000 ––We have studied sulfur isotope ratios (33S/32S, 34S/32S, and 36S/32S) archived in the volcanic and ferruginous rocks of the Sumozero–Kenozero (ca. 2.9 Ga) and Kostomuksha (ca. 2.7 Ga) greenstone belts of the Fennoscandian Shield. The obtained data provide new arguments for developing ideas of the bacterial activity in the Archean ocean and the involvement of sulfur in the biogenic cycle and also indicate no free oxygen in the Archean Earth’s atmosphere. The isotope data on 34S and 33S show a high activity of sulfate-reducing and sulfur-disproportionating bacteria in the surface environments of Archean sedimentary rocks. The discovery of 33S and 36S anomalies in the studied rocks is the main evidence for the anoxic atmosphere during the formation of Meso- and Neoarchean deposits in Karelia.","PeriodicalId":506591,"journal":{"name":"Russian Geology and Geophysics","volume":"14 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140248344","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geochemistry of Crude Oils from the Bazhenov Horizon (West Siberia)","authors":"E. Fursenko, A. Kontorovich, E. Kostyreva, N.L. Padalko, A. Rodchenko, S. Ryzhkova","doi":"10.2113/rgg20234682","DOIUrl":"https://doi.org/10.2113/rgg20234682","url":null,"abstract":"\u0000 —The Bazhenov horizon is the main source rock stratum of the West Siberian petroleum province, which possesses significant resources of hard-to-recover hydrocarbons, making it a unique exploration target. The study summarizes geochemical data on crude oils (39 samples) collected from pools within the Bazhenov and Tutleima formations. A comparative analysis of the carbon isotope composition and geochemical parameters calculated from the composition of the identified saturated and aromatic compounds (pristane/phytane, C29/C27 steranes, C35/C34 homohopanes, tricyclane index, relative concentrations of dibenzothiophenes) confirm a common aquatic genotype of the studied oils and their genetic affinity to the organic matter of the same age. At the same time, significant variations in the main physical and chemical characteristics of the studied Bazhenov oils may be caused their fractionation during migration processes.","PeriodicalId":506591,"journal":{"name":"Russian Geology and Geophysics","volume":" 14","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139392142","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Petroleum Potential and Organic-Matter–Oil Correlation in the Rocks of the Upper Riphean Iremeken Formation in the Kamo Arch of the Baikit Anteclise (Siberian Platform)","authors":"L. Boldushevskaya, S. Fadeeva, I. V. Goncharov, P. Trushkov, V. V. Samoilenko, M. Veklich, N.B. Krasil’nikova, D.M. Savchik, G.U. Rudaya, A.B. Turova, Yu.L. Nikolaeva","doi":"10.2113/rgg20234656","DOIUrl":"https://doi.org/10.2113/rgg20234656","url":null,"abstract":"\u0000 ––A complex of laboratory studies of Riphean rocks and oils was carried out by the organic-geochemistry methods to construct a basin model for the Kamo arch of the Baikit anteclise of the Siberian craton. We compared the parameters of the organic matter (OM) and oils of the Upper Riphean Iremeken carbonaceous member by biomarker hydrocarbons. Analysis of the obtained chromatography–mass spectrometry data showed an unordinary group hydrocarbon composition of extracts from the OM and oils and low contents of cheilanthanes and steranes in them. Within the Kamo arch, the Upper Riphean Iremeken OM-enriched deposits with a high petroleum potential might have reached the peak of petroleum generation only in the deepest part of the Madra trough; thus, the traps could not be completely filled with oil. The distribution of tricyclic terpanes in the rock bitumens from the studied wells testifies to immature OM in the Iremeken Formation. However, in the most submerged zones of the Kamo arch and in the adjacent areas, oil was generated from the OM of the Iremeken Formation. This is evidenced by the oils of the Upper Iremeken Subformation in the Kuyumbinskoe field and the Ter’-Kamo license area.","PeriodicalId":506591,"journal":{"name":"Russian Geology and Geophysics","volume":"227 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139395263","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Kinetic Characteristics of Kerogens in the Kuonamka Complex, Lower and Middle Cambrian of the Siberian Platform","authors":"L. Burshtein, A. A. Deshin, A.N. Kozyrev, T.M. Parfenova, P. I. Safronov, E. S. Yaroslavtseva","doi":"10.2113/rgg20234673","DOIUrl":"https://doi.org/10.2113/rgg20234673","url":null,"abstract":"––The kinetic characteristics of kerogen (activation energy and frequency factor distributions of the initial generative potential) determine the dynamics of naphthide generation during catagenesis. In the previous studies on quantitative modeling of naphthidogenesis in the Kuonamka source rocks, the kinetic characteristics were taken by analogy with the known kerogens from other complexes and provinces. It seems relevant to determine the effective kinetic characteristics of the kerogen from the Kuonamka source rocks from experimental data. To estimate the kinetic parameters, specialized multi-rate pyrolysis studies were performed. The variations in pyrolysis data was reported to be presumably associated with the conditions of kerogen and source rock formation during accumulation and diagenesis of organic matter. The effect of carbonate and organic carbon contents on the temperature range of the second pyrolysis peak is recorded. Reconstruction of the average (effective) kinetic characteristics of kerogens from the Kuonamka source rock, was conducted using data on kerogens from Serkinsky-5 and 10 and Tit-Ebya-6 wells, which are less degraded than kerogens from Ust’-Maiskaya-366 well and probably attained the early mesocatagenesis grades. The current average effective kinetic characteristics of kerogen were estimated and corrected for the possible partial degradation of reference samples. The obtained effective kinetic models of kerogen are compared with models of kerogens of various genetic types known from the literature. The estimated effective kinetic characteristics of kerogens or Menil-1 and Type B kerogens with similar characteristics are to be taken, as a first approximation, in regional historical-genetic (basin) modeling of naphthide generation in the Kuonamka source rock.","PeriodicalId":506591,"journal":{"name":"Russian Geology and Geophysics","volume":"85 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139155743","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geological Position, Sources, and Age of Mingling Dikes of the Northwestern Margin of the Tuva–Mongolian Massif in Western Sangilen, Southeastern Tuva","authors":"V.A. Yakovlev, I. Karmysheva, V. Vladimirov, D. Semenova","doi":"10.2113/rgg20234589","DOIUrl":"https://doi.org/10.2113/rgg20234589","url":null,"abstract":"––The best source of information about the specific features of magmatism in collision zones is the late collisional tectonomagmatic stage, which is associated with the largest volume and diversity of the resulting magmatic associations. In this paper, granitoid and mafic late collisional magmatism is considered using the example of Early Caledonian igneous complexes of Western Sangilen (Tuva–Mongolian massif). Results of geochronological, petrographic, petrogeochemical, and mineralogical studies of the rocks of the Saizyral mingling dike and salic dikes are presented. Approximately ~485 Ma, high-potassium granitoid massifs formed simultaneously with the intrusion and occurrence of a complex of granitoid and mingling dikes. The Saizyral mingling dike resulted from the joint intrusion and mixing of basic and silicic magmas in a low-pressure region within the Erzin shear zone at a middle crust depth level. Interaction of contrasting magmas is comprised of two stages. The first stage occurs during the transport of a contrast mixture and comes down to intensive mechanical mixing and the introduction of LIL and HFS elements, as well as Th and U from granitoids into the mafic rocks. This changes the geochemical characteristics of the mafic rocks. The second stage is when the joint crystallization of magmas is accompanied by gravitational sedimentation of denser mafic magmas and the formation of narrow zones of intermediate composition at the contact of contrasting rocks.","PeriodicalId":506591,"journal":{"name":"Russian Geology and Geophysics","volume":"85 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139239010","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}