Seismic anisotropy in the central Tien Shan unveils rheology-controlled deformation during intracontinental orogenesis

نویسندگان

چکیده

Abstract The initiation and evolution of compressional intracontinental orogens are favored by rheologically weak lithosphere underneath; however, how this weakened responds to the regional stress regime remains vigorously debated. Tien Shan mountains in central Asia provide best example illustrate deep deformational responses orogenesis. We present new constraints on nature seismic anisotropy crust upper mantle through shear-wave splitting analyses. Our results reveal a sharp change orientations crustal anisotropic fabrics two sides mountains. convergence-parallel fast northern segment closely related lower-crustal simple-shear deformation caused underthrusting Kazakh Shield, whereas depth-independent orogen-parallel southern suggest vertically coherent pure-shear thickening response northward indentation Tarim Basin. thickened has partly foundered into mantle, contributing accelerated shortening late Cenozoic. observations demonstrate complex tectonic processes that rheological properties bounding blocks can play significant role shaping lithospheric structures orogens.

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ژورنال

عنوان ژورنال: Geology

سال: 2022

ISSN: ['0091-7613', '1943-2682']

DOI: https://doi.org/10.1130/g49633.1