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Apatite fission-track (AFT) thermochronological modeling as a diagnostic tool for periods of stability (peneplanation) and tectonic activity (orogeny) has been broadly used in tectonic studies of Central Asia in recent years. We discuss more than 100 AFT ages of samples from the Kyrgyz Tien Shan and Altai and compare them with AFT data from northern Kazakhstan. Geological, geomorphological, and AFT data indicate intense activity in the Late Cenozoic Eurasian continental interior. The impact from the India-Eurasia collision on the northern Tien Shan, Altai, and northern Kazakhstan regions showed up at 11, 5, and 3 Ma, respectively, as a result of stress propagation into the continent, with the ensuing reactivation and mountain growth. We hypothesize that a distant effect of the Late Cenozoic India-Eurasia collision was to rejuvenate Paleozoic fault zones and to deform the Mesozoic sedimentary cover north of the collision front as far as the West Siberian Plate. The reactivation facilitated formation of tectonic oil and gas traps. The activity in northern Central Asia under the effect of the Indian indentation into Eurasia appears to continue and may evolve to include uplift of southern West Siberian plate with uplift. 相似文献
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V Sanfelix ET Gòmez MM Jordán T Sanfeliu S Pallarés AB Vicente 《Environmental Geology》2005,47(6):811-819
The objective of this work is to assess the concentrations of three factions of air particles (settable particles, TSP and PM10) and the levels of several toxic elements in a clay atomisation industry through aerosol sampling at several points inside an industrial plant. Mechanical activities, which produce diffuse emissions, are the main process of discharge of particles in both indoor and outdoor workplace environments in the atomisation plant. The levels of As, Cd, Pb, Zn, Ba and Ni increase in the zones with higher concentrations of particles and lower ventilation. The concentrations of As and F are not influenced by the recycling processes. The levels of Cd and Pb do not show great enrichment in air particles collected inside the atomisation plant although the content of both elements is associated with ceramic muck recycling. Finally, the content of B in waste water is mainly transferred in gaseous phase to the atmosphere during the process of drying by atomisation. 相似文献
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土地利用/土地覆被变化遥感监测研究 总被引：3，自引：0，他引：3
根据1990年和1999年两期TM/ETM 遥感数据,运用遥感分类中的监督分类方法,全面分析乌鲁木齐市的土地利用的数量变化特征和空间变化特征,阐明了区域土地利用变化的区域特点。 相似文献
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Travin A. V. Buslov M. M. Bishaev Yu. A. Tsygankov A. A. 《Doklady Earth Sciences》2023,507(3):S396-S399
Doklady Earth Sciences - The thermal history of the Late Paleozoic granitoids of the Angara–Vitim batholith (AVB) was reconstructed using a comprehensive approach including U/Pb, 40Ar/39Ar,... 相似文献
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A. S. Buslov Yu. D. Kotov V. N. Yurov M. V. Bessonov P. A. Kalmykov E. M. Oreshnikov A. M. Alimov A. V. Tumanov E. A. Zhuchkova 《Solar System Research》2011,45(3):226-230
This paper deals with the organizational structure of ground-based receiving, processing, and dissemination of scientific
information created by the Astrophysics Institute of the Scientific Research Nuclear University, Moscow Engineering Physics
Institute. Hardware structure and software features are described. The principles are given for forming sets of control commands
for scientific equipment (SE) devices, and statistics data are presented on the operation of facility during flight tests
of the spacecraft (SC) in the course of one year. 相似文献
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Seismic-tomography studies were conducted in the Kyrgyz Tien Shan using two different observation schemes. The first was based on the arrival times of P and S waves from regional earthquakes recorded with local seismological networks (local scheme). Nonlinear tomographic inversion based on the LOTOS algorithm was used to construct the 3D distributions of P and S wave velocities in the crust beneath the Kyrgyz Tien Shan and to refine the earthquake locations. The second scheme was used to study the upper-mantle structure based on data from global earthquake catalogs (regional scheme). All the data on waves which at least partly travel within the volume studied were used here, including (1) those from regional earthquakes recorded at world seismic stations and (2) teleseisms recorded at the local stations. This approach was earlier applied to calculate the upper-mantle structure beneath Asia. We used a fragment of this structure beneath the Tien Shan and adjacent areas. A series of synthetic tests was performed to estimate the resolution provided by both schemes. The tomography shows traces of the delamination of the Tarim mantle lithosphere from south to north. Also, the local and regional schemes reveal evidence for cold-matter descent from north to south in the northern Tien Shan but on a much smaller scale. Low velocities in the upper mantle beneath the Tien Shan might indicate lithospheric thinning. These data suggest that mantle-lithosphere delamination is taking place underneath both the northern and the southern margins of the Tien Shan collision belt. Lack of the mantle lithosphere beneath the Tien Shan leads to lithospheric weakening and active deformation, thus causing intense orogeny. 相似文献
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Occurrence of phosphatic microfossils in an Ediacaran–Cambrian mid-oceanic paleo-atoll limestone of southern Siberia 总被引：1，自引：1，他引：0
New phosphatic microfossils were recently discovered in an Ediacaran–Cambrian mid-oceanic paleo-atoll limestone in the southern Gorny Altai Mountains in southern Siberia. Microfossils with calcium phosphate shells are abundant in the limestone that occurs as an exotic block within a Cambrian accretionary complex in the Kurai area. SEM observations confirm that the calcium phosphatic shells are ellipsoidal and equal-sized, about 200–300 μm in diameter. Shell walls are about 1 μm thick. As the absence of external and internal structures hinders a detailed comparison/identification, these microfossils are tentatively treated here as paleontological problematica. EPMA-analysis confirmed the concentration of elements P and Ca in microfossil shells and the absence in the matrix, suggesting the primary phosphatic composition of the shells. Because phosphatic microfossils are generally scarce in the Ediacaran but abundant from the Lower Cambrian, in particular within pre-trilobitic SSF assemblages, the phosphatic fossil-bearing limestone in the Kurai area possibly belongs to the Lower Cambrian. The present find proves that mid-oceanic paleo-seamounts as well as continental shelf domains had already been inhabited by diverse metazoans in the Ediacaran–Cambrian transitional interval. 相似文献