LITHOSPHERE (Russia)最新文献

{"title":"Geophysical study of the Earthʼs crust (Northern regions of Russia and the Arctic sea shelf)","authors":"M. Chadaev, V. Kostitsyn, V. Gershanok, G. Prostolupov, M. Tarantin","doi":"10.24930/1681-9004-2023-23-1-52-67","DOIUrl":"https://doi.org/10.24930/1681-9004-2023-23-1-52-67","url":null,"abstract":"Research subject. The results of the geological and geophysical study of the Earth’s crust on the territory of two regions are presented: the northwestern part of the East European Platform and the adjacent water area, as well as the waters of the East Siberian, Chukchi Seas and the Russian eastern sector of the Arctic Ocean, including the Lomonosov ridge and the Mendeleev–Alpha rise. The research is focused on mapping the Moho, the thickness and type of the Earth's crust necessary to substantiate the outer boundary of the continental shelf.Materials and methods. The authors’ original materials obtained during the processing of gravimetry and magnetometry data in the VECTOR system were used. Based on the relationship between gravity anomalies and density variations of rocks, the shape, size of the studied objects, and their deep mutual position are characterized.Results. The constructed schemes and profiles of the deep structure of the Earth's crust, obtained using the VECTOR method, were tested using the European Moho global seismic model. The positive forms of the Moho section and the raised parts of the shelf surface correspond to the positive anomalies of the transformed gravitational field. The spread of the structure of the field of continental anomalies in the Pevek–Anadyr area to the marine part of the territory under consideration can indirectly confirm the belonging of the Lomonosov Cr., the Mendeleev and Alpha ridges to the continental type of crust.Conclusion. Global, i.e., related to the territory of the globe, three-dimensional models of Moho allow us to expand and deepen the amount of knowledge about the features of the shelf structure. Geopotential fields in the VECTOR system display the tectonics of the studied environment systematically and comprehensively compared to is representation according to the scheme of profile seismic studies.","PeriodicalId":18202,"journal":{"name":"LITHOSPHERE (Russia)","volume":"99 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81418228","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":"Crystal chemistry of globular layered silicates of the Troitsko-Bainovskoye fre-clay deposit (Middle Urals)","authors":"Y. Simakova","doi":"10.24930/1681-9004-2023-23-1-133-146","DOIUrl":"https://doi.org/10.24930/1681-9004-2023-23-1-133-146","url":null,"abstract":"Research subject. The composition and crystal chemistry of glauconite from the open deposits (K2cn-cp) of the Poldnevskaya area of the Troitsko-Bainovskoye deposit of fire clays.Materials and methods. An analysis of the mineralogical and crystallochemical properties of glauconite was carried out using a set of modern analytical methods (“Geonauka” Centre for Collective Use, IG FRC Komi SC UB RAS): X-ray diffractometry, IR-spectroscopy, scanning electron microscopy, modeling of diffraction profiles.Results and conclusions. The crystal-chemical features of glauconite were determined. Two main glauconite varieties (green and light green) in the rocks of the Zaikovskaya suite were distinguished and their differences and degree of maturity have been established. It was found that dark green globules are close to glauconite and represent a more “mature” variety, while the light green ones are a disordered mixed-layer mineral of the mica (glauconite) – smectite series and are a product of incomplete replacement of the original smectite by glauconite. Phase heterogeneity of glauconite globules was revealed. It has been established that the rocks of the Troitsko-Bainovskoe deposit are exposed to intensive transformation under the influence of acidic surface and technogenic waters, which result in the destruction of the initial minerals and the appearance of secondary mineralization. Clay minerals of the glauconite-bearing rocks are represented by disordered mixed-layer phases of predominantly illite/smectite type.","PeriodicalId":18202,"journal":{"name":"LITHOSPHERE (Russia)","volume":"28 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87513766","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":"Reference section of the Uk Formation of the Upper Riphean (Karatavian) in the Alatau anticlinorium (Southern Urals)","authors":"N. Sergeeva, V. Puchkov, S. Dyakova, T. S. Zaitseva","doi":"10.24930/1681-9004-2023-23-1-38-51","DOIUrl":"https://doi.org/10.24930/1681-9004-2023-23-1-38-51","url":null,"abstract":"Research subject. The deposits of the Uk Formation of the Upper Riphean (Karatavian) in the Alatau anticlinorium (Southern Urals) were studied in the section of the right bank of Basu river and its tribute Manaysu located to the east of the Kulmas settlement.Results. The structure of the sections of Uk Formation along Basu River (Kulmas) in the Alatau anticlinorium and its stratotype at the Yuryzan river near town of Ust-Katav in the Suleimanovo anticline is identical: the Lower Uk Subformation is represented by irregular alternation of sandstones, siltstones and shales with rare layers of limestones and dolomites with Patomella kelleri Raaben and Tungussia bassa Kryl. stromatolites and microphytolites of the IV complex, while the Upper Uk – by limestones with Linella ukka Kryl. and Linella simica Kryl. stromatolites and microphytolites of the IV complex. However, the sandstones and siltstones of the Lower Uk Subformation in the stratotype at the Yuryuzan river (Ust-Katav) are polymictic, while in the reference section along Basu river (Kulmas) they have mostly quartz composition. These petrographic features may be a result of different provenance. In the rocks of Uk Formation in the Basu section (Kulmas), the epigenetic processes (dolomitization and silicification) are strongly manifested. In the limestones of the Upper Uk Formation the caverns and fractures along with layers enriched by a bitumen (?) are observed.Conclusions. The reference section of the Uk Formation along the river Basu (Kulmas) is proposed as a hypostratotype, in which the deposits of the lower subformation of the Uk suite are most fully represented in comparison with the stratotype along the river Yuryuzan (Ust-Katav). Cavernous-fractured limestones of the Uk Formation with layers enriched by a bitumen (?), may be regarded as an interesting search object for hydrocarbons, taking into account that a large hydrocarbon deposit has been discovered in the silicified cavernous-fractured dolomites of Kamovskaya Formation of the Upper Riphean of the Siberian platform.","PeriodicalId":18202,"journal":{"name":"LITHOSPHERE (Russia)","volume":"71 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85194448","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":"Possible influence of CaO admixture in the Pre-Ural Foredeep terrigenous rocks on the determination of the source rocks composition based on geochemical data","authors":"А. V. Maslov, G. Mizens, L. V. Badida","doi":"10.24930/1681-9004-2023-23-1-21-37","DOIUrl":"https://doi.org/10.24930/1681-9004-2023-23-1-21-37","url":null,"abstract":"Research subject. The article discusses the analysis results of correlations between the calcium oxide content and a number of other rock-forming oxides in the Asselian sandstones and in the Middle–Upper Permian clay rocks of the Pre-Ural trough with some of their inherent ratios of rare and trace elements (La/Sc, Th/Cr, Th/Co, Ce/Cr, etc.), which act as traditional indicators of source rocks composition.Methods. Our main method is to analyze the correlation coefficients values between different pairs of oxide-indicator ratios. During the discussion, we proceeded from the fact that a statistically significant (both positive and negative) correlation between calcium oxide, ignition loss, or magnesium oxide, on the one hand, and the values of indicator ratios of rare and trace elements, on the other hand, suggest the dependence of the noted ratios on the features of the aluminosilicate matrix replacement with carbonate minerals.Results. We have established, there is a statistically significant positive or negative correlation between the calcium oxide content in Permian terrigenous rocks (different sedimentary intervals of the Pre-Ural Foredeep) and some indicator ratios of rare and trace elements (Asselian sandstones – Th/Cr, Ce/Cr and Eu/Eu*, Urzhum–Viatsk clay rocks – La/Sc, Th/Co, (La/Yb)N, etc.). As a result, the values of these ratios depend to some extent on the carbonate minerals content (mainly calcite) in terrigenous rocks. These carbonate minerals corrode the aluminosilicate matrix and in one way or another change the primary contents and ratios of impurity elements. On the contrary, there is no significant correlation between the CaO content in the Asselian sandstones and the values of La/Sc, Th/Co, etc. There is no correlation between the CaO content and the Ce/Cr ratio in the Urzhum–Viatsk clay rocks.Conclusions. We suggest, the correlation (not statistically significant at 5% confidence level) between calcium oxide content (in sandstones and clay rocks) and some indicator ratios of rare and trace elements can be considered as an indication that such ratios can be used to reconstruct the source rocks composition.","PeriodicalId":18202,"journal":{"name":"LITHOSPHERE (Russia)","volume":"66 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77961186","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":"On the nature, composition and gas content of epigenetic mineralization in the salt column of the Verkhnekamskoe deposit (on the example of the Usolsky mine)","authors":"I. I. Сhaikovskiy, O. V. Ivanov, M. Bubnova, T. V. Fedorov","doi":"10.24930/1681-9004-2023-23-1-117-132","DOIUrl":"https://doi.org/10.24930/1681-9004-2023-23-1-117-132","url":null,"abstract":"Research subject. The paper considers the tectonic position of the zone of epigenetic mineralization in the salt strata of one of the mines of the Verkhnekamskoye deposit, the gross and microelement chemical composition, gas content and component composition of gases.Materials and methods. To assess the composition of the original and epigenetic formations, structural and geological observations were carried out in mine workings, sampling, determination of the gross chemical composition (XRF, Bruker S8 Tiger spectrometer), trace elements (Aurora M90 inductively coupled plasma mass spectrometer), gas content and component composition of associated gases (gas chromatograph 450-GC company “Varian, Inc”).Results. It has been established that vein mineralization fills delamination cracks in the cores of the synclinal fold and is accompanied by zones of halite leaching and sylvite recrystallization. Further down the section, possible sources of K-oversaturated brines are recorded, which are generated in numerous small structures such as pop-ups or kink bands. The enrichment in light hydrocarbon gases, as well as easily soluble salts and mobile elements (KCl, CaCl2, MgCl2, Br, Rb, Li, Sr, Zn, Cu, Co, Te, Se, Sn, Pb), reflects their formation from sediment-brines mobilized during folding from sylvinite rocks.Conclusions. One of the mechanisms for the mobilization of fluids, salts, and trace elements in the salt column is characterized, which is associated with the folded appearance of small scattered chambers in the lower silyvinite bed KrIII and subsequent pulsating migration up the section along the synclinal bends of larger folds in the bed KrII. It is shown that in the process of formation of the zone of epigenetic mineralization, differentiation of small elements and gases occurs, which is associated with different sorption properties of halite, sylvin, and clay material.","PeriodicalId":18202,"journal":{"name":"LITHOSPHERE (Russia)","volume":"41 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87209546","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":"Biostratigraphy and lithofacies of the Middle-Upper Devonian in the Ayazovo oil field (North-Eastern of Bashkiria)","authors":"E. N. Gorozhanina, V. Pazukhin, V. M. Gorozhanin, Z. A. Voykina","doi":"10.24930/1681-9004-2023-23-1-68-91","DOIUrl":"https://doi.org/10.24930/1681-9004-2023-23-1-68-91","url":null,"abstract":"Research subject. Oil-bearing deposits of the Middle-Upper Devonian in the Ayazovo oil field located in the north-east of Bashkiria.Materials and methods. A detailed description and subdivision of the section were carried out based on the borehole cores of the Rustamovskaya area using biostratigraphic and lithofacial analysis, micropalaeontology of spores and conodonts.Results. The sediments of the Pashian, Timan, Sargaevo, Domanic and Mendym horizons are identified, their lithofacial features are described, and sedimentation conditions are determined.Conclusions. The studied succession of the Devonian sediments demonstrates cyclical changes in terrigenous and carbonate shelf sedimentation environments caused by eustatic sea level change and complicated by the tectonic events associated with the formation of uplifts and troughs of the Kama-Kinel system at the end of the Frasnian.","PeriodicalId":18202,"journal":{"name":"LITHOSPHERE (Russia)","volume":"63 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80695777","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":"Geodynamic aspects of the metallogeny-magmatic zonality relationship of orogenic volcanic-plutonic belts","authors":"A. M. Kurchavov","doi":"10.24930/1681-9004-2023-23-1-5-20","DOIUrl":"https://doi.org/10.24930/1681-9004-2023-23-1-5-20","url":null,"abstract":"Research subject. The orogenic marginal-continental and collisional volcanic-plutonic belts, and the zonality of magmatism and metallogeny within them, as well as the relationship of endogenous metallogeny with magmatic zonality and geodynamics of belt formation.Materials and methods include the long-term studies of the Devonian and Upper-Paleozoic belts of Kazakhstan and the Cretaceous-Paleogenic belt of Sikhote-Alin; an analysis of the alterations in the material parameters of magmatites; the identification of the front and rear parts of the belts and the arrangement features of metallogenic zones within their limits; and the data on other belts of the world.Results. For the marginal continental belts, an asymmetric change of the tholeiitic and low-potassium magmatites of the calcareous-alkaline petrochemical series of the frontal zone of the belt into the magmatites of the high-potassium branch of the calcareous-alkaline and shoshonite series of the rear zone (Devonian and Upper Paleozoic belts of Kazakhstan) has been established. In the same direction, the elemental, as well as the genetic type of deposits changes: pyrite copper-polymetallic frontal zones are replaced by molybdenum-copper-porphyry rear zones (near the border with the frontal zone) and then by rare metal ones. This is also characteristic of the Andean and Okhotsk-Chukchi belts. The collision belts are characterised by symmetrical zonality with a change from rare metal deposits in the centre to copper-polymetallic deposits at the edges (Mongolia). In some cases (Sikhote-Alin and Japan), the continuity of the marginal-continental belt is disrupted as a result of the mantle diapir (or plume), symmetrical magmatic and metallogenic zonality occurs with the change of polymetallic manifestations (near the ocean–continent boundary) to rare-metal ones in the distance. Conclusions. The change in the material parameters of the magmatites of the marginal-continental belts correlates with the removal of their ranges from the ocean–continent transition zone to the interior of the latter. In this case, copper-polymetallic pyrite ore formations are replaced by copperporphyry and then by rare metal ones in this direction. This is due to subduction processes. The collision situation is characterised by a symmetrical zonality of material magmatic parameters with respect to the crowding zone and a symmetrical arrangement of metallogenic zones with a change of rare metal deposits in the crowding zone to copper and polymetallic along the frame. These data are important for metallogenic prediction, as well as for palaeotectonic reconstructions.","PeriodicalId":18202,"journal":{"name":"LITHOSPHERE (Russia)","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90920701","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":"On the nature of the Zhamanshin crater (Northern Cis-Aralian Region)","authors":"V. A. Bykadorov, G. M. Gorkin, M. Antipov, K. E. Knizhnik","doi":"10.24930/1681-9004-2023-23-1-92-116","DOIUrl":"https://doi.org/10.24930/1681-9004-2023-23-1-92-116","url":null,"abstract":"Research subject. The Zhamanshin structure is located in the northern Aral Sea region and represents the outcrops of pre-Mesozoic rocks among Paleogene deposits. This structure has been known in the literature as a young meteorite crater for more than half a century.Aim. To consider all available geological and geophysical information on the structure and material composition of rocks and explain the development features of the Zhamanshin structure in relation to its position within the Late Paleozoic suture-collision zone of the Eastern-Uralian fold system.Materials and methods. The materials of geological surveys of various scales, as well as the interpretation of geophysical data, satellite images, data on the material composition of rock samples and paleotectonic reconstructions were analysed. In addition, the published literature on the meteorite origin of the Zhamanshin structure was analysed.Results. The main structural features of the Zhamanshin structure are rather associated with the accretion-subduction processes in the Paleozoic and strike-slip movements, especially active in the Pliocene, than with an impact event. The young age of glasses (from 10 thousand to 50 Ma) remains unproven due to unreliable methods used. The composition of the glasses allows them to be attributed to Paleozoic volcanic rocks, while some samples of slags and glasses may be of technogenic origin.Conclusions. Almost all arguments in favour of the meteorite origin of the Zhamanshin structure are questioned. A more realistic conclusion is that it has formed by deep tectonic and geological processes. The Zhamanshin structure is a dissected rounded upland with a ring of Paleozoic rocks along the edges and a hollow in the middle, which is associated with an eroded Carboniferous caldera. After the collision in the middle of the Carboniferous, the entire Northern Aral Sea remained an area of denudation until the beginning of the Cretaceous. After that, terrigenous lacustrine-alluvial strata up to 300 m thick had accumulated. During the Paleogene and Miocene, this upland with the remnants located along a circular rampart tens of meters high was covered by marine and continental sediments. In the Pliocene, the area was subjected to active strikeslip movements with the formation of the Tasaran mega-anticline with the Zhamanshin, North-Zhamanshin and Tasaran uplifts. The Irgiz-Tobolsk shear-thrust had limited and uplifted the western flank of the Zhamanshin structure, while feathering faults resulted in the formation and subsidence of a rounded depression around the Paleozoic caldera in the centre of Zhamanshin.","PeriodicalId":18202,"journal":{"name":"LITHOSPHERE (Russia)","volume":"32 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76207018","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":"Hydrocarbon formation in CaCO3–FeO–H2O–SiO2 and Fe3C–H2O–SiO2 systems under thermobaric conditions of the upper mantle","authors":"A. Serovaiskii, V. Kutcherov","doi":"10.24930/1681-9004-2022-22-6-840-846","DOIUrl":"https://doi.org/10.24930/1681-9004-2022-22-6-840-846","url":null,"abstract":"Research subject. The possible influence of the SiO2 environment as the most common component of the mantle on the deep abiogenic synthesis of hydrocarbons in the CaCO3–FeO–H2O and Fe3C–H2O systems under thermobaric conditions corresponding to those in the upper mantle is investigated.Materials and methods. Experiments were carried out using a high-pressure unit in Toroid-type chambers across the thermobaric range of 2.0–4.0 GPa and 220–750°C. CaCO3 and Fe3C were used as carbon donors, H2O was used as a hydrogen donor, and SiO2 was used as an environment. The synthesized products were analyzed by gas chromatography and X-ray diffraction.Results. Across the entire temperature and pressure range used, mixtures of light alkanes with the predominance of methane were obtained. The composition of the hydrocarbon systems synthesized in the presence of SiO2 was similar to that obtained at the same thermobaric parameters without SiO2, depending exclusively on the temperature and pressure of synthesis. The conducted X-ray diffraction analysis of solid products demonstrated transformation of quartz into coesite at 400°C and 750°C.Conclusions. According to the conducted investigation, the qualitative and quantitative composition of hydrocarbon systems formed during the abiogenic synthesis of hydrocarbons in the presence of SiO2 corresponds to the results of similar experiments without SiO2. However, the total yield of the hydrocarbon systems in the SiO2 environment decreases. The dependence of the composition of the synthesized hydrocarbon systems on the thermobaric conditions of synthesis remains in the SiO2 environment.","PeriodicalId":18202,"journal":{"name":"LITHOSPHERE (Russia)","volume":"88 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85172536","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":"Medium-term earthquake forecasts by the LURR method on the example of the strongest earthquakes of the 21st century","authors":"A. Zakupin, N. Boginskaya","doi":"10.24930/1681-9004-2022-22-6-872-881","DOIUrl":"https://doi.org/10.24930/1681-9004-2022-22-6-872-881","url":null,"abstract":"Aim. To carry out a retrospective forecast of the eight strongest earthquakes (with a magnitude greater than 8) of the 21st century using the Load/Upload Response Ratio (LURR) method.Methods. Calculations were performed according to the authors’ original data processing technique, which had been successfully tested while studying the seismicity of Sakhalin Island. A significant advantage of this methodology consists in using fixed (basic) parameters of mathematical processing and sampling of calculated earthquakes (geometry of the calculation area and sequestration by magnitude). This enables researchers to conduct not only retrospective studies, but also real-time forecasting. In the present paper, a seismic catalog of the United States Geological Survey (USGS) was used.Results. For four of the considered earthquakes, precursors in the form of anomalies of the LURR parameter were identified. These anomalies had manifested themselves in periods from six months to two years before the earthquake, which is consistent with our results for Sakhalin. At the same time, no other anomalies (false alarms) were recorded in three cases. For the other four earthquakes, no anomalies were recorded at all. It is noted that the level of seismic activity (in the operating range of magnitudes) in these cases allows the smoothing window to be reduced. In some cases, the calculation for a window twice as small (180 days) revealed pre cursors, at the same time as contributing to the appearance of additional, false anomalies.Conclusions. It was confirmed that the authors’ methodology for data preparation and calculation parameters selection, as well as the LURR method, apparently have limited possibilities for extrapolating to various seismically active regions of the planet. There may be different reasons, which have not been considered in the present paper due to the uncertainty associated with the capabilities of the USGS network.","PeriodicalId":18202,"journal":{"name":"LITHOSPHERE (Russia)","volume":"15 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91010611","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}