Structural and geological studies in the Naryn and Atbashi depressions (Tien Shan) and geological interpretation of magnetotelluric data

• Published in: IOP conference series. Earth and environmental science Vol. 929; no. 1; pp. 12007 - 12014
• Main Authors: Przhiyalgovskii, E S, Rybin, A K, Morozov, Yu A, Lavrushina, E V, Leonov, M G, Bataleva, E A
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 01.11.2021
• Subjects: Basements; Cenozoic; Earth crust; Electrical conductivity; Electrical resistivity; Elongated structure; Fragmentation; Geologic depressions; Geological structures; Geology; Geophysical studies; Geophysics; Orogeny; Paleozoic; Permeability; Sedimentary rocks; Segments; Seismic analysis; Two dimensional models
• ISSN: 1755-1307; 1755-1315
• DOI: 10.1088/1755-1315/929/1/012007

Abstract The article presents the results of complex geological and geophysical studies in the Naryn depression and Atbashi depression in the Middle Tien Shan. They included the geological interpretation of new magnetotelluric data along the detailed profile crossing the key segment of the Tien Shan, and the study of the morphology and spatial position of the sedimentary cover and basement structures. The compilation of the results of structural-geological and geophysical studies makes it possible to create a 2D model of the upper-crust geological structure, consistent with the structure of the electrical conductivity to depths of about 10 km and to analyze the structural features of deeper horizons. Two types of structural patterns of the electric conductivity, corresponding to the sedimentary complexes of the cover and the folded-metamorphic complexes of the basement, have been identified. Sedimentary rock complexes in depressions have a high electrical conductivity and subhorizontal structure. The upper crust above the K2 density layer is characterized by an alternation of rocks volumes with contrasting conductivity, elongated vertically. The recorded structure of the field confirms the presence of steep zones of fluid permeability and fragmentation, noted earlier in seismic profiles and probably corresponding to the Paleozoic structures of fragmentation of the Earth’s crust, activated during Alpine orogeny. Comprehensive research allow to characterize the deformations of the Cenozoic sedimentary complex and the surface of the Paleozoic basement associated with the Alpine activation of the key segment of the Tien Shan.