Strain rates for the southern Siberian craton derived from GPS measurements (original) (raw)
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Geotectonics
Geological data on the Precambrian basic complexes of the Siberian Craton and their isotopic age are considered. The three main episodes of Precambrian basic magmatism of Siberia correspond to certain stages of the geodynamic evolution of the craton and the Earth as a whole. In the Late Paleoproterozoic, largely in the south and the north of the craton, the basic rocks were emplaced against the background of post collision extension, which followed the preceding collision–accretion stage responsible for the formation of the craton. In the Mesoproterozoic, primarily in the north of the craton, basic magmatism was controlled by dispersed within�plate extension apparently caused by the impact of a mantle plume. Neoproterozoic basic magmatism widespread in the southern and southeastern parts of the craton was caused by rifting, which accompanied breakdown of the Rodinia supercontinent and opening of the Paleoasian ocean along the southern margin of the Siberian Craton.
Interexpo GEO-Siberia
The signs of the collisional structure are expressed in the upper crust by the advanced Priverhoyansk forland and local hinterland basins is separated by a high-speed array, most likely of magmatic origin. The boundary of the craton at an angle of about 15 ° is submerged under the crust of the folded system, where the characteristic layer of the craton lower crust at velocity of 6,7–6,9 km /s is absent and the velocity in a whole crust is reduced, as well as along the Moho from 8,3 to 7,9-8,0 km / s.
2013
Shen (Shen et. al., 1996) method has been applied to the GPS measurements results in order to investigate crustal deformation of the Azerbaijan and surrounding areas. The field of velocity vectors obtained from the results of the GPS measurements conducted from 1998-2012 time period in Azerbaijan, İran, Georgia and Armenia used to estimate the deformation rates. Compression observed along the Greater Caucasus, Gobustan, Kura depression, Nakhchivan and the border areas with Iran. Compression axis show that reduction of the Earth's crust in the Greater Caucasus happens towards N-NE direction. The maximum value of the strain rate of about 400 × 10-9 per year was observed in the area between points KHID (Khidirly) and SHIK (Shikhlar) and here compression axis changes direction to the SW-NE. Along with areas of compression in the deformation field, there is a evident area where almost no deformation. Such zones are the Pre-Caspian-Guba region and northern Gobustan. Extension zones are observed in the small Caucasus: in Gedebey (GEDA), Shusha (SHOU) areas and in the area located between the points DAMO and the PIRM, where the dilatation rate reaches 100 ×10-9 per year.
Field Research in Strashnaya Cave (Northwestern Altai) in 2019: New Data on the Stratigraphy
Problems of Archaeology, Ethnography, Anthropology of Siberia and Neighboring Territories, 2019
Для этого был зачищен и изучен стратиграфический разрез по линии «Е» в центральной части карстовой полости. Было составлено геологическое описание стратиграфических подразделений, а также отобраны образцы для основных литологических анализов. В составе разреза было выделено восемь слоев, содержащих археологический материал среднего палеолита, а также три стерильных в археологическом отношении слоя. Детальное изучение стратиграфии сопровождалось отбором образцов для датирования методом OSL. Проведенные исследования позволили составить единую схему осадконакопления в пещере, а также определить генезис основных стратиграфических подразделений. Литологические наблюдения, дополненные лабораторными исследованиями, позволят определить наименее потревоженные слои в пещере. OSL-датированием отобранных образцов возможно установить абсолютный возраст их формирования.
Late Cenozoic faulting and the stress state in the south-eastern segment of the Siberian platform
Geodynamics & Tectonophysics, 2017
We have studied the structural geology and geomorphology of the fault zones in the junction area of the Angara-Lena uplift and the Predbaikalsky trough. We have analyzed faults and folds and reconstructed paleostresses for this junction area named the Irkutsk amphitheatre. Our study shows that syn-fold (Middle Paleozoic) faults include thrusts, reverse faults and strike-slip faults with reverse components, that occurred due to compression from the neighbouring folded region. Recently, contrary to compression, faulting took place under the conditions of extension of the sedimentary cover: most of these recent faults have been classified as normal faults. In the Late Cenozoic, the platform cover was subjected to brittle and partly plicative deformation due to the NW-SE-trending extension that is most clearly observed in the adjacent Baikal rift. Thus, the divergent boundary between the Siberian block of the North Eurasian plate and the Transbaikalia block of the Amur plate is a zone of dynamic influence, which occupies the area considerably exceeding the mountainous region on the Siberian platform. Important factors of faulting are differentiated vertical movements of the blocks comprising the platform. Such vertical movements might have been related to displacements of brine volumes. In the Late Cenozoic basins, movements along separate faults took place in the Late Pleistocene-Holocene.
LITOSFERA, 2018
Исследование сфокусировано на седиментологии и стратиграфии огромного вендского (эдиакаранского) осадочного бассейна на юго-западе Сибирского кратона для освещения происхождения его главных и детальных подразделений. Осадки коррелируются вдоль края кратона и в его внутреннюю область с использованием стратиграфических секвенций, включающих гляциальные и постгляциальные отложения. Особенное значение для корреляции имеют кластические комплексы венда чапской, тасеевской, оселковой и байкальской серий, сложенные аллювиальными отложениями. Детально проанализированы строение аллювиальной айсинской свиты оселковой серии венда Присаянья и ее корреляция с верхними подразделениями чапской, тасеевской и байкальской серий юго-западной периферии Сибирской платформы и подразделениями чехла внутренних ее районов. Детальное описание айсинской свиты сделано на базе единой классификации литофаций и алгоритмов их последовательностей. Выделены два подкомплекса венда (эдиакарана)-нижний континентально-морской и верхний континентальный. Континентальноморской подкомплекс в краевых погруженных зонах Сибирской платформы формировался преимущественно на шельфе окраинных морей, а также на постгляциальных зандрах прибрежной аллювиальной равнины под влиянием внутрикратонных источников кластического материала. Континентальный подкомплекс, которому принадлежат речные отложения айсинской свиты, образован крупными красноцветными и пестроцветными толщами аллювия в передовых прогибах и формировался центростремительными речными системами, направленными от внешних источников материала на север и северо-восток в эпиконтинентальное море центральных районов Сибирской платформы. На начальной и поздней стадиях активизации поздневендского орогенеза возникали большие глубокие песчаные реки с внутрирусловыми барами, тогда как постоянные сетчатые и сплетенные песчано-иловые реки возникали на пассивной стадии орогенеза. Наибольшая проградация аллювиальных отложений на Сибирскую платформу маркируется нижними пачками русловых отложений айсинской свиты, а также немчанской, мошаковской, хужирской и качергатской свит, а на плите-боханской песчаниковой пачкой чорской свиты.
Geodynamics & Tectonophysics, 2013
The article presents results of field studies and interpretation of tectonophysical data from profiles in the valleys of Bystritsa Nadvornyanskaya, Prut, Pistynka (the rightside tributary of the Prut river), Belyi and Chernyi Cheremosh, and Seret rivers. The stress fields reconstructed from different groups of joints and slickensides in flysch and molasse sediments of the Skyba and BoryslavPokuttya nappes are analyzed. A combination of the structuralparagenesis and kinematic analysis methods provided for determination of deformation modes, their sequences, and average azimuth values of orientations of the principal axes of regional paleostress fields (σ 1 , σ 2 , σ 3) which were manifested through the Alpine stage of the Ukrainian Carpathians development. The paleostress fields were reconstructed for the southeastern part of the Skyba nappe of the Ukrainian Carpathians and the BoryslavPokuttya nappe of the Carpathian foretrough. The article describes similarities and differences in the stressand strain states, specific features of the paleostress fields, and the ratio of joints in different groups (oblique and perpendicular to the rock layers) and slickensides in the area under study.
Modern displacement of active faults in South-Yakutian coal-bearing depression on the GPS data
Вулканология и сейсмология, 2019
For a quantitative assessment of the current horizontal velocity of the surface displacement of the crust in southern Yakutia in recent years, was organized the first and only points of permanent GPS observations in the city of Neryungri (NRG) and the city of Chulman (CHL3). Both points of observation are located within the southern margin of the Eurasian plate, near the system of active structures separating it from the Amur plate. To estimate the relative displacement, the period of joint operation of these two GPS points was chosen, namely from June 29, 2015 to December 1, 2016. The rate of displacement of the point in Neryungri, calculated for a 5-year period (from 27.10.2011 to 01.10.2016), was 21.83±0.73 mm/year in the East-West direction and 12.26±0.25 mm/year in the North-South direction in the international reference basis ITRF2014. The obtained values differ slightly from the theoretical values of the velocity of the Eurasian lithospheric plate at the specified point. The ...