SILURIAN DEPOSITS OF THE NORTHERN SLOPE OF THE DZHUNGARIAN ALATAU

Silurian deposits were first identified on the northern slope of the Dzhungarian Alatau by F. A. Makarenko on the basis of fauna collected in the Aksu river basin. In 1938, Silurian deposits, 400 kilometers in length, were mapped by M. M. Yudichev. Later investigations have shown that these beds are Devonian in age. It seems obvious that Paleozoic sediments uncomformably overlying the Precambrian (?) crystalline foundation began accumulating in the Lower Devonian. The principal Paleozoic structures are the result of Hercynian folding, not the final phase of Caledonian folding, as assumed by Makarenko.