BURIED VALLEYS IN MOUNTAIN REGIONS, COASTAL LOWLANDS AND CONTINENTAL SHELF IN THE ASIAN PART OF RUSSIA

Abstract

In mountain areas, adjacent coastal lowlands and continental shelf in the Asian part of Russia a variety of buried valleys is found very different in their forming conditions and morphology. Classification of buried valleys is suggested that shows a great variety types, their formation conditions, morphometric and morphological characteristics. Buried valleys are divided into two main groups: 1) valleys formed in areas of rapid crustal uplifts and differential tectonic movements; 2) valleys formed in areas of tectonic subsidence such as transient areas between uplifting and sinking structures, inversion or inherited tectonic basins, individual valley sections preserved at the crossings of subsiding tectonic blocks, valleys buried in coastal lowlands, valleys buried in continental shelf due to the global sea level rise. In most areas, buried valleys are represented by a combination of different age generations of the above types. The degree of inheritance of the identified types of valleys varies and depends on the type and amplitude of tectonic movements. The larger the amplitude of tectonic movements is, the poorer is the inheritance of river network. In the areas of differential tectonic movements, inheritance may be detected not only for river network pattern, but also for morphodynamic types of river channels and even individual channel forms.