VOLCANITES OF THE FEDOTOVSKAYA SWITCH IN SECTIONS BY R. KOYVA
Description is given of acidic and basic volcanites along the river. Koyva, placed in the Fedotovskaya Formation of the upper Riphean and accompanying subvolcanic intrusions of granite-porphyries, and also containing carbonaceous shales. Threefold division of the Fedotovskaya Formation was established.