Deposits of the Middle Carboniferous, first established in the Zaisan fold system back in the 30's and originally assigned to the Permian, for about half a century have been the object of close attention and lively debate ...

In most areas of W. Kazakhstan, the boundary between the Lower and Middle Carboniferous is indistinct, gradual, which is the reason for the allocation of local stratigraphic subdivisions, the age of which is interpreted as Upper Namur-Middle Carboniferous undissected or as Upper Namur-Middle Carboniferous ...

The region under consideration is located in the western part of the Zaisan Hercynian folded region, bounded in the southwest by the Caledonian structures of the Chingiz-Tarbagatai middle mass (geoanticlinal zone of the first kind, according to V. A. Nikolaev) and in the northeast by the Charsky uplift (internal geoanticline of the second kind, according to V. A. Nikolaev) .....