Abstract

Study of Devonian pelecypods of the Kuznetsk basin permits the several assemblages valuable for biostratigraphic subdivision to be distinguished.

The assemblage of bivalve molluscs of the Salairkinsky unit, belonging, according to the standard stratigraphic succession of the USSR, to the lower part of the Middle Devonian, is very large and diverse. It includes some generalized forms which are close to those of Western Europe: Pterinea (Tolmaia) lineata lineata Goldfuss, Myalina auriculata Spristersbach, Conocardium rhenanum Beushausen, Goniophora trapezoidalis Kaysen, etc., in addition to such local Altai-Sayany forms as Pterinea (Tolmaia) squamosa Khalfin, Mytilarca terbratuloides Khalfin, Goniophora metula W. Kul., and Eoschizodus limus W. Kul.

Among the Western European forms, there is a predominance of Siegenian and Emsian types, only a few of which extend as high as the lower part of the Eifelian Stage. The Altai-Sayan forms also have an Early Devonian appearance.

On the basis of the pelecypods, the Salairkinsky unit correlates with the Emsian Stage of the Ardennes-Rhine Region and probably with the Upper Emsian. In the USSR, is correlates with the Kireevsky unit (Lower part of D₂) of Mountain Altai, and the Burubaisky and Sardzhalisky units (D₁) of northwestern Pribalkhash.