New geophysical data on the depth structure of the Tien Shan intermontane depressions

Abstract

New results of a detailed study of the Issyk Kul intermontane depression system by electromagnetic and geomagnetic methods are presented. A profile-based magnetometric survey across the water area of Lake Issyk Kul revealed a positive 30-km-wide magnetic anomaly at approximately +100 nT in intensity. The nature of this anomaly can be explained by the exposure of Late Paleozoic granitoid intrusions. The problems of the construction of a regional geoelectric model along the Barskaun magnetotelluric profile, which crosses the central Issyk Kul Depression in the meridional direction, are discussed. On the basis of generalization of previously obtained data from complex studies along the MANAS geophysical transect, a structural-geodynamic lithosphere section was constructed along this transect. In this section, the interrelationships between the surface and deep seismic and geoelectric structures are clearly reflected in the lithosphere of the Naryn-Atbashi intermontane depression system.