{"title":"EARLY NEOPROTEROZOIC GRANITOIDS IN THE RYAZANOVSKY MASSIF OF THE YENISEI RIDGE AS INDICATORS OF THE GRENVILLE OROGENY AT THE WESTERN MARGIN OF THE SIBERIAN CRATON","authors":"A. Nozhkin, O. Turkina, I. Likhanov, Y. Ronkin","doi":"10.5800/gt-2024-15-2-0745","DOIUrl":"https://doi.org/10.5800/gt-2024-15-2-0745","url":null,"abstract":"Studies of the geological history of the Yenisei Ridge are important not only for understanding the tectonic evolution of mobile belts at the boundaries of ancient cratons but also for problem solving whether the Siberian craton was a part of the Rodinia supercontinent. The mineralogical-petrological, geochemical and isotope-geochronological studies yielded new data on the petrogeochemical composition, petrogenesis features, U-Pb age of zircon, and Sr and 147Sm-143Nd isotopic parameters for the rocks of the Ryazanovsky granitoid massif located near the Yenisei fault zone of the Yenisei Ridge. These rocks are represented by high-ferruginous peraluminous varieties and are comparable to A-granites or highly differentiated I-granites. Their composition evolves from normal to subalkaline granites and leucogranites, characterized by increased concentrations of highly charged and radioactive elements. Isotopic (Sr, Nd) characteristics of the rocks indicate generation from an ancient crustal substrate, the average age of which corresponds to the Paleoproterozoic. The formation of these granites at the Meso-Neoproterozoic boundary (1013±9.9 Ma) corresponds to the early stage of the Grenville orogeny and the formation time of the structure of the Rodinia supercontinent. This episode of regional crustal evolution is correlated with the synchronous successions and similar style of tectonothermal events on the periphery of large Precambrian cratons (Laurentia and Baltica), thus confirming the reliability of the proposed paleocontinental reconstructions of incorporation of the Siberian craton into the Rodinia.","PeriodicalId":505746,"journal":{"name":"Geodynamics & Tectonophysics","volume":" 574","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140682562","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}
S. I. Dril, V. Kovach, А. В. Kotov, K.‐L. Wang, А. М. Larin, Y. Iizuka, H.-Y. Lee
{"title":"GRANODIORITES OF OLEKMINSKY COMPLEX OF THE EASTERN TRANSBAIKALIA: U-Pb LA-ICP-MS ZIRCONS GEOCHRONOLOGY AND AGE POSITION OF COMPLEX","authors":"S. I. Dril, V. Kovach, А. В. Kotov, K.‐L. Wang, А. М. Larin, Y. Iizuka, H.-Y. Lee","doi":"10.5800/gt-2024-15-1-0740","DOIUrl":"https://doi.org/10.5800/gt-2024-15-1-0740","url":null,"abstract":"The palingenic calc-alkaline granitoid massifs of the Olekminsky complex form a magmatic belt stretching within the Western-Stanovoy terrane in the northeastern direction for more than 700 km. New U-Pb LA-ICP-MS dates for zircons from the granodiorites of the Marekta-Bereinsky massif of the Olekminsky complex and the granodiorites of the Yamninsky massif of the Krestovsky complex were obtained, amounting to 371±4 Ma and 364±5 Ma, respectively. These geochronological data are well consistent with the 355–358 Ma ones, therefore suggesting the Late Carboniferous age of quartz-diorite-granodiorite-granite rocks of the Olekminsky complex. However, these dates are not correlated with the existing legends of geological maps covering the area of the Western-Stanovoy structural-formation zone or the Western-Stanovoy terrane, as the intrusive formations of the Olekminsky complex are dated as the Early Paleozoic. In addition, new geochronological data call into question distinguishing of a separate Early Paleozoic Krestovsky granitoid complex.","PeriodicalId":505746,"journal":{"name":"Geodynamics & Tectonophysics","volume":"36 6","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139961896","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}
V. Kaftan, P. Dokukin, A. Manevich, V. Tatarinov, R. Shevchuk
{"title":"DEFORMATION INTERACTION OF STRONG EARTHQUAKES OF 2010–2016 IN THE ZONE OF INFLUENCE OF THE HIKURANGA SUPERPLUME (NEW ZEALAND) ACCORDING TO GPS OBSERVATIONS","authors":"V. Kaftan, P. Dokukin, A. Manevich, V. Tatarinov, R. Shevchuk","doi":"10.5800/gt-2024-15-1-0735","DOIUrl":"https://doi.org/10.5800/gt-2024-15-1-0735","url":null,"abstract":"Between 2010 and 2016, a series of 11 strong M>6 earthquakes occurred in New Zealand. In the area covering the epicentral zones of these seismic events, the spatiotemporal characteristics of movements and deformations of the Earth’s crust were obtained based on the processing of continuous satellite GPS observations at 64 points of the geodetic network. Using these data, we have studied the evolution of horizontal movements and deformations in order to reveal the possible relationship between the observed deformational and seismic processes. Analysis has been made on the total shear deformation, since the main tectonic structures of the region are faults with a shear mechanism of displacement of their sides. The presence of a giant mantle superplume in the area was the reason for the study of the behavior of horizontal dilatation deformation, and horizontal and vertical crustal motions. Based on the obtained digital deformation models, there were created kinematic visualizations, which are synoptic animations providing direct observations of the seismic deformation process and their heuristic analysis. The study revealed that a series of the strongest earthquakes may be interconnected by a long-term single deformation process, which is caused by the occurrence of an anomalous total shear deformation. The general maximum of shear deformation, dilatation deformation, and horizontal and vertical displacements are concentrated in the center of mantle superplume activity. Prior to strong seismic events, there occur zones of deficit (minimum) displacements of the Earth’s crust in the area of future epicenters, which is of research interest in terms of predicting their locations.","PeriodicalId":505746,"journal":{"name":"Geodynamics & Tectonophysics","volume":"27 7","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139962269","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}
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