Some problems of the neotectonics of Aldan-Chulma depression

Abstract

The Late Cenozoic history of Aldan-Chulma depression manifests itself in the special features of distribution and composition of Quaternary deposits belonging to periglacial, alluvial and slope series, as well as in patterns of watershed heights. On this basis has been revealed the zonality of neotectonic structures of the depression, approximately corresponding to the zonality of Mesozoic structures. However, relations between Mesozoic and Cenozoic structural plans are those of inversion: maximum Cenozoic uplifts correspond to maximum. Mesozoic downwarping. The analysis of the distribution of watershed heights within the outlined neotectonic zones suggests the fragments of three planation surfaces of different age correlated with general Siberian surfaces as well as deformations of one of these surfaces which fragments are mostly widespread. Arch-block character of the neotectonic structures is established and the amplitudes of deformations of different order are defined.