The Cenozoic history of the Chuya depression (Gorny Altai): Structure and geodynamics

Detailed geological and morphological mapping of transition zones from the Chuya depression to the surrounding mountains in the north (Kurai Ridge) an d west (Chagan-Uzun massif) allowed us to infere that bath changed their ev olution dynamics through time. As a sedimentary basin bounded by uplifts, t he Chuya depression initiated in the Middle Miocene - Early Pleistocene and was then, apparently, a graben formed together with the neighboring Chagan -Uzun horst. The present-day structure of the basin was produced by Intence compression. In the latest Early Pliocene a ramp formed, and in Late Plioc ene and Quaternary time its northern boundary was rejuvenated by thrusting and oblique-slip faulting. The Cenozoic relief formation In southeastern Go rny Altai provides a good illustration of gradual propagation of deformatio ns related to the India-Eurasia collision, which since the Late Pliocene ha ve been making a boundary between the Altai orogen and the Tuva-Mongolia mi croplate, chiefly following Late Paleozoic regional faults. The main regula rities of the structure and evolution of the collisional boundary became ev ident owing to a special study, the results of which can be used in descrip tion of similar boundaries of neotectonic structures in Inner Asia.