Russian Journal of Pacific Geology最新文献

{"title":"Sedimentation History of the Aldan–Maya Sedimentary Basin (Southeast of the North Asian Craton) Reconstructed from a Seismostratigraphic Section","authors":"E. P. Razvozzhaeva","doi":"10.1134/s1819714024700040","DOIUrl":"https://doi.org/10.1134/s1819714024700040","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The sedimentation history of the Aldan–Maya sedimentary basin was reconstructed based on a seismostratigraphic section. In total, ten reconstructions were obtained showing the formation stages of the main sedimentary structures—the Riphean (Late Proterozoic) Aldan and Yudoma–Maya troughs and the overlying Vendian–Cambrian deposits, as well as the stages of tectonic restructurings. The use of the seismostratigraphic section and geological data to investigate the formation of the sedimentary cover contribute to a more substantiated and visual understanding of the evolution of the structure over more than 1.5 Ga.</p>","PeriodicalId":49583,"journal":{"name":"Russian Journal of Pacific Geology","volume":"119 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2024-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141255843","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Landslide Activation during the Development of Mountainous Areas","authors":"V. A. Lobkina, Yu. V. Gensiorovsky","doi":"10.1134/s1819714024700076","DOIUrl":"https://doi.org/10.1134/s1819714024700076","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The development of mountainous areas leads to activation of hazardous exogenic processes, primarily landslides and mudflows. One of the important factors determining the intensity of these processes and having a significant impact on their characteristics is moistening of rocks in potential landslide and mudflow masses. This work considers the case of landslide activation at Gornyi Vozdukh ski resort in December 2021. A predictive model is presented for the formation of landslides induced by excessive moistening of slopes, which was calibrated to the conditions of southern Sakhalin. To calibrate the model, the data on the cases of landslides and mudflows within a 30-km radius from Yuzhno-Sakhalinsk hydrometeorological station are collected. The predictive model uses data on daily, antecedent, and cumulative precipitation. All these data are publicly available, which makes it possible to calibrate the model for any nearest hydrometeorological station. The daily precipitation threshold making possible the formation of landslides and mudflows in the given territory is determined as 51.4 mm.</p>","PeriodicalId":49583,"journal":{"name":"Russian Journal of Pacific Geology","volume":"8 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2024-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141255832","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ulban Terrane (Zone) as Part of the Jurassic Accretionary Complex of the Sikhote-Alin Orogenic Belt","authors":"A. I. Khanchuk, I. V. Kemkin, V. E. Kirillov, V. V. Ivanov, M. F. Kiryanov, S. I. Trushin","doi":"10.1134/s1819714024700015","DOIUrl":"https://doi.org/10.1134/s1819714024700015","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The paper presents new data on the age of Triassic–Jurassic cherts replaced up section by siliceous mudstones, then by mudstones, which together with basalts form thin (up to hundreds of meters) plates and lenses that wedge out along strike at different levels of the multikilometer terrigenous section of the Ulban terrane (zone). These deposits in the Nimelen subzone (Albazino gold deposit area) formed in the Norian–Early Toarcian; host terrigenous deposits formed in the Pliensbachian–Bathonian. The age of cherts and siliceous–clayey rocks in the Mewachan subzone is Middle Triassic–Callovian, and that of host terrigenous rocks is Middle–Late Jurassic (including the Tithonian). Comparison of deposits of the Ulban terrane with well-studied deposits of the Samarka terrane similar in age and composition allows us to consider the Ulban terrane (zone) as part of the Jurassic accretionary complex of the Sikhote-Alin orogenic belt. There are also sufficient signs to consider that its structural features are consistent with the subduction model. This idea is based on the fact that Triassic–Jurassic cherts and siliceous–clayey rocks, which accumulated over about 45 Ma at a rate of about 1.8 m/Ma, are considered the sedimentary cover of the oceanic plate. At the same time, a gradual transition from cherts to mudstones is evidence of movement of the oceanic plate into the subduction zone. The occurrence of its fragments in the terrigenous section is the result of their detachment in the trench and under the overhanging slab. Tectonostratigraphic columns of the subzones of the Ulban terrane and a zonal scheme of the Jurassic accretionary wedge, including four structural-age levels, have been compiled.</p>","PeriodicalId":49583,"journal":{"name":"Russian Journal of Pacific Geology","volume":"120 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2024-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141255964","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"First Data on Late Cretaceous Terrigenous Deposits of the Upper Part of the Zhuravlevka–Amur Terrane Section in the Lower Amur River Area: Evidence from U/Pb Detrital Zircon Geochronology","authors":"I. A. Alexandrov, A. I. Malinovsky, V. V. Ivin, S. Yu. Budnitskiy","doi":"10.1134/s1819714024700039","DOIUrl":"https://doi.org/10.1134/s1819714024700039","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The paper reports data on the age and composition of poorly studied Cretaceous clastic rocks of the Lower Amur River area, which are part of the Zhuravlevka–Amur terrane and are attributed to the Berriasian–Valanginian Komsomolsk series. U/Pb dating of detrital zircons yielded reliable dates of 99 and 90 Ma for the Gorin and Pioneer formations, respectively. Thus, a sedimentary complex with a Late Cretaceous sedimentation age was identified for the first time in the Sikhote-Alin orogenic belt based on detrital zircon geochronology. In composition and detrital zircon age distribution pattern, the studied rocks are more similar to sediments of the upper, Hauterivian–Albian part of the Zhuravlevka–Amur terrane section rather than to those of the lower, Berriasian–Valanginian part. In rocks of the Pioneer Formation, the youngest zircon population with an age of about 90 Ma makes up more than 40% of all dated grains. The main source of detrital material of this age was probably proximal andesites hosting the Mnogovershinnoe deposit and granitoids of the Nizhneamurskii Complex. The source of detritus for sediments of the ∼99 Ma Gorin Formation was probably felsic rocks from the Albian–Cenomanian igneous province of Pacific Asia. The discrepancy between the Late Cretaceous age obtained by us and the paleontologically established Berriasian–Valanginian stratigraphic age of the formations requires additional research. New data on the Late Cretaceous age of the Zhuravlevka–Amur sediments of strike-slip marginal-continental basin requires revision of the geologic evolution of the terrane and the entire Sikhote-Alin orogenic belt.</p>","PeriodicalId":49583,"journal":{"name":"Russian Journal of Pacific Geology","volume":"128 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2024-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141255848","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Formation of Gold Mineralization under Amphibolite Facies Metamorphism: Ykan Deposit (Baikal–Patom Belt)","authors":"A. E. Budyak, Yu. I. Tarasova, A. V. Chugaev, N. A. Goryachev, T. A. Velivetskaya, A. V. Ignatiev","doi":"10.1134/s1819714024700052","DOIUrl":"https://doi.org/10.1134/s1819714024700052","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Black shale sequences whose metamorphic grade exceeds the regional greenschist facies are considered by most researchers exclusively as promising for alluvial gold. The paper reports the results of a study of the Ykan deposit, located within the epidote–amphibolite facies zone, and its comparison with previously studied deposits localized in the greenschist-facies alteration zone. It was found that the the main factor of localization of the Ykan gold deposit is its lithological and stratigraphical restriction to the contact between carbonaceous phyllite shales and sandstones of the Aunakit Formation in the hanging wall of the anticline. The ore mineralization of the deposit is represented by a subsequent change of early dia-catagenetic pyrite (py-I, py-II) → metamorphogenic pyrrhotite (po, cpy, asp) → metamorphogenic-metasomatic pyrite–base metal (cpy, asp, py-III, gln, sph, pn, mrc) → postore pyrite (py-IV) assemblages. The ore stage is characterized by the highest possible PT parameters in the early ore metamorphic phase and their decrease at the ore-productive phase. Data on variations in the sulfur and lead isotopic composition indicate that they were transported into the ore fluid from the host metasedimentary sequences of the Aunakit Formation. Comparison of the obtained parameters of the Ykan deposit with the previously studied Sukhoi Log, Golets Vysochaishii, Ugakhan, and Krasnoe deposits confirmed that the Ykan deposit can be attributed to the Sukhoi Log-type deposits.</p>","PeriodicalId":49583,"journal":{"name":"Russian Journal of Pacific Geology","volume":"69 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2024-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141255833","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Deep Seismic Structure of the Pacific Tectonic Belt along the 8-DV Reference Profile","authors":"V. M. Soloviev, A. S. Salnikov, V. S. Seleznev, T. V. Kashubina, A. V. Liseykin, N. A. Galeva","doi":"10.1134/s1819714024020088","DOIUrl":"https://doi.org/10.1134/s1819714024020088","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>This article presents the results of deep seismic studies over the Sikhote-Alin fragment of the 8-DV reference geophysical profile running across the large fold structures of the Pacific tectonic belt, that is, the Sikhote-Alin Orogenic Belt with the superimposed Middle Amur sedimentary basin and the East Sikhote-Alin volcanoplutonic belt. A deep seismic section of the Earth’s crust and upper mantle with the distribution of longitudinal wave velocities is constructed. In the upper part of the section, P-wave velocities vary from 4.0–5.0 km/s within the Middle Amur sedimentary basin and the eastern part of the Eastern Sikhote-Alin volcanoplutonic belt to 5.5–5.6 km/s in the central part of the Sikhote-Alin Orogenic Belt. It was established that the thick Paleozoic sedimentary complex within the Middle Amur sedimentary basin is faulted and folded in a complex manner. Crystalline rocks with a compressional wave velocity of 6.0–6.2 km/s occur at depths from 8 to13 km in different parts of the Middle Amur sedimentary basin and at depths of 4–6 km within the Sikhote-Alin orogenic complex. Compressional wave velocities of the crust in the Sikhote-Alin fragment of the 8-DV profile are between 6.3 and 6.35 km/s. The crust varies in thickness from 32–34 km in the northern part of the fragment to 36–37 km in its central and eastern parts. Along the Moho, P-wave velocities are 8.1–8.3 km/s; a number of areas with reduced <i>V</i>_p of 7.8 to 8.0 km/s were identified in the junction zones of large crustal blocks. <i>P</i>-wave data were used to identify anomalies which were correlated with structural-tectonic zones, deep fault zones, and seismicity. The thick Middle Amur sedimentary basin was distinguished along the Central Sikhote-Alin deep fault. This basin is filled by Paleozoic low-velocity deposits and is displaced along the fault plane by 4–5 km at its junction with the Sikhote-Alin Orogenic Belt. Zones of increased heterogeneity in the upper crust projected onto the area within the contours of the Middle Amur sedimentary basin are characterized by increased seismicity.</p>","PeriodicalId":49583,"journal":{"name":"Russian Journal of Pacific Geology","volume":"6 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2024-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140887849","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Distribution and Genesis of Hydrocarbon Gases in the Bottom Sediments of the Laptev–Siberian Sea Zone of the East Arctic Shelf","authors":"A. I. Gresov, A. V. Yatsuk","doi":"10.1134/s1819714024020040","DOIUrl":"https://doi.org/10.1134/s1819714024020040","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Gases from bottom sediments of the Laptev–Siberian Sea zone contain methane (up to 8.3047 cm³/kg) and its homologues (up to pentane including) totaling 0.0259 cm³/kg. The established values of the carbon isotope composition of methane (δ¹³С), the molecular weight of the hydrocarbon fraction, the weight concentrations of С₁–С₅ hydrocarbons and their ratios, the “wetness” and “transformation” coefficients of the hydrocarbons fraction indicate the presence of various syngenetic and epigenetic gases in different source rocks: bottom sediments, peatlands, coal, gas, and gas hydrate? deposits, solid bitumen, igneous rocks, and inferred oil and gas reservoirs. It has been established that the vertical and lateral distribution of hydrocarbon gases in sediments depends on the influence of a complex of geological factors: fold and fault tectonics, magmatism and seismic activity in the region, coal, oil and gas potential and bitumen content, organic saturation and lithological composition, hydrogeological, geocryological, and other conditions for accumulation of gases or their degassing.</p>","PeriodicalId":49583,"journal":{"name":"Russian Journal of Pacific Geology","volume":"12 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2024-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140887854","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sources of Terrigenous Sediments of the Lower Cambrian Bystraya Formation of the Argun Massif and Paleogeodynamic Settings of Their Accumulation","authors":"Yu. N. Smirnova, A. V. Kurilenko, V. B. Khubanov, S. I. Dril","doi":"10.1134/s1819714024020076","DOIUrl":"https://doi.org/10.1134/s1819714024020076","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>This paper presents the results of mineralogical, geochemical, isotope, and geochemical (Sm–Nd) studies of siltstones from the upper Bystraya subformation of the Argun continental massif, as well as U–Pb dating of detrital zircon grains from them. The main goal of the research was to identify the main sources of clastic material, to reconstruct the paleogeodynamic environment of accumulation, and to constrain the lower age limit for the formation of terrigenous rocks of the upper Bystraya subformation. The mineralogical composition of the studied rocks indicates their accumulation in an environment associated with subduction processes. The trace element composition of siltstones from the subformation suggests the presence of rocks of mixed composition in the source area in terms of their silica content. Based on Sm–Nd isotope and geochemical data, it was established that the main sources of clastic material for siltstones of the stratigraphic unit were Paleoproterozoic rocks and (or) younger rocks whose formation is associated with the reworking of the Paleoproterozoic continental crust. Most of the zircons from the studied siltstone sample of the upper Bystraya subformation are Neo- and Paleoproterozoic in age. Their sources are probably Neo- and Paleoproterozoic igneous rocks widespread within the Argun massif in China. The ages of the youngest zircons (556 ± 9 and 566 ± 10 Ma) isolated from siltstones of the upper Bystraya subformation were used to constrain the lower limit of their accumulation at the middle Ediacaran.</p>","PeriodicalId":49583,"journal":{"name":"Russian Journal of Pacific Geology","volume":"70 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2024-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140887861","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Composition and Formation Conditions of Nitrogen–Siliceous Thermal Waters of the Amgu Group (Northeast of the Primorsky Krai)","authors":"I. V. Bragin, A. A. Pavlov, G. A. Chelnokov, V. Yu. Lavrushin, N. A. Kharitonova","doi":"10.1134/s1819714024020039","DOIUrl":"https://doi.org/10.1134/s1819714024020039","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>This article presents new data on the ionic, microcomponent, and isotope compositions of thermal waters of the Amgu group classified as sodium-bicarbonate waters with low mineralization (up to 0.2 g/L), high contents of silica (up to 24 mg/L), lithium, tungsten, and molybdenum, and pH = 8.5–9.7. The influence of neotectonics and Quaternary magmatism on the composition and conditions of formation of nitrogen–siliceous thermal waters is shown. Using δD and δ¹⁸O values in thermal and background waters, their atmogenic origin was proved, and the source area of mineral waters was identified. The calculated deep reservoir temperature of 77–81°С indicates the formation of water resources in the crust at significant depths (as much as 2.5 km). The efficiency of using the multicomponent geothermometry method for low-temperature reservoirs is shown.</p>","PeriodicalId":49583,"journal":{"name":"Russian Journal of Pacific Geology","volume":"42 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2024-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140887980","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structural–Geodynamic Systems of the Eastern Arctic Region","authors":"B. V. Senin, V. Yu. Kerimov, M. I. Leonchik, R. N. Mustaev, R. A. Mamedov","doi":"10.1134/s1819714024020064","DOIUrl":"https://doi.org/10.1134/s1819714024020064","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The research considered in the paper was aimed at studying the structure and evolution of the Eastern Arctic structural–geodynamic systems. The tectonic model of the base of the Eastern Arctic plate section determines their vertical zonality in terms of structure and tectonics based on the interpretation of seismic and other geophysical survey data correlated at a varying reliability degree with the studied sections in the adjacent or remote areas. Accordingly, the vertical structure and formation composition models built on this basis are largely hypothetical and tend to change (even fundamentally) as geological and geophysical information accumulates. The geodynamic analysis of formation of the Eastern Arctic structural–geodynamic systems was based on tectonic–geodynamic paleoreconstructions recorded the interaction between blocks of the consolidated crust. The results we obtained made it possible to considerably update, expand and, in some cases, refine understanding of a structure of the basement and individual reference horizons of the sedimentary cover in this part of the water area. It is concluded that the East Arctic waters are of great interest in terms of hydrocarbon exploration. However, the assessment of their hydrocarbon potential is difficult due to the poor geophysical knowledge and lack of wells.</p>","PeriodicalId":49583,"journal":{"name":"Russian Journal of Pacific Geology","volume":"19 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2024-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140887797","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}