TERRIGENOUS-CARBONATE CROSS-SECTION IN THE MIDDLE COURSE OF THE VITIM RIVER: CORRELATION, AGE, AND GEODYNAMICS

Abstract

The descripton has been provided for the cross-section (12 km) of a thick sediment unit on the left bank of the Vitim River, opposite the Nizhny Orlov and Dannaya rivers. This place is related to the Karalon-Mamakan area of the Baikal-Muya belt of the Baikal folded area. The changes have been made to the names formally assigned to the following stratigraphic subdivisions: Sulban series was renamed Chayangra formation, and Kelyan subseries was renamed Karalon formation. Evidence has been found for the complex folded and faulted structure and litological-facial characteristics of the cross-section. Some evidence has been provided to confirm that the Karalon formation is younger than the Chayangra formation. When this result is comapared to the well-studied subdivisions of the northern areas of the region, it is apparent that the Karalon formation may well correlate with the Dalnetaiga horizon of the Lower Vendian, the Chayangra formation – with the Ballaganakh series of the Late Riphean, and its layers at the bottom are similar in composition to the the Medvezhevsk horizon.

Keywords

• baikal folded area
• vitim river
• neoproterozoic
• correlation
• depositional environment