Upper crust structural and morphological ensembles of the Pamir-Tien Shan segment of Central Asia and their reflection in geophysical fields

Abstract

Structural-morphological ensembles of different ranks for Pamir — Tien Shan segment of Central Asia and their possible correlation with the data of remote geophysical investigations are considered in the paper. Results of such correlation analysis are discussed. A bright example of the morphostructures of cross-regional scale on the territory of the Eurasian continent are the mountain systems of the Pamirs and the Tien Shan, historically, structurally and geologically two different provinces which differ in configuration, internal structure and features of evolution and orogenesis. The paper presents the results of a comprehensive study of the deep structure of the lithosphere of the southern Tien Shan and the Pamirs along the TIPAGE profile. The analysis of the geophysical inhomogeneities distribution of the profile section shows that the deep structure of the southern Tien Shan differs significantly from that of the Pamirs. The orphostructures of the regional scale and their reflection in the detailed magnetotelluric sounding data are considered on the basis of the results of geological and geophysical study of the Tien Shan tectonic zones: Kochkor Basin and Naryn Basin-Baibichetoo- Atbashi Basin. The study reveals a good correlation between the surface structure determined by geomorphological and structural methods and the deep geoelectric section, built on the high-resolution magnetotelluric sounding data. The paper also considers examples of morphostructures of local-regional scale, meso- and micro-scales, identified by the authors of the paper within the study of the structural features of tectonic blocks and rock mass of the Northern Tien Shan. All examples of surface and deep structures correlation presented in the paper demonstrate the paragenetic uniformity of different-scale tectonic structures revealed by geological and geophysical methods within large and tectonically homogeneous segments of the Tien Shan and Pamir crust.