On the quantitative analysis of planation surfaces (a case of Western Transbaikalian region)

Abstract

Statistical technique permits reliable determination of modal levels of the planation surfaces using a graph of distribution of altitudes general population. The altitudes district button frequency within longitudinal geomorphological zones together with variation curves analysis allows to distinguish features of structure and changes in the planation surfaces evolution, Two stages can be distinguished during 150 million years of evolution, The first accomplished stage, about 113 million years long, ends with peneplainization, the second stage (37 million years) is still at its ascending phase which is manifested in constant uplift amplitudes and accelerated cyclic development. Unambiguous identification of the planation surfaces will permit to apply them on a broader scale to the paleo-geomorphological analysis and to practical task, i. e. to estimate the depth of erosional downcutting into ore-bearing structures within large region of Meso-Cenozoic mineralization.