Abstract

The Lower Devonian carbonate sediments of the Soviet Arctic yield various and abundant Tabulata, which commonly form distinct beds. The writer studied the Tabulata of Novaya Zemlya and the Taimyr Peninsula and, in the Lower Devonian sediments, distinguished three distinct tabulate assemblages, two of which are diagnostic for the two regions and the third for the lower part of the Eifelian. The boundary between Lower and Middle Devonian (Eifelian) is drawn at the base of the Favosites regularissimus beds.

For each of the recognized assemblages of Tabulata, restricted to certain beds or tongues, or their parts, some morphological features of Favosites are recognized. The generic composition of all the assemblages of Tabulata is similar to that of synchronous sediments of the Kuznetsk basin, Salair, and northeastern USSR.

The study of the Lower Devonian Tabulata of Novaya Zemlya suggests that their generic and specific compositions, as well as the morphological character of the walls of the Favositinae, is distinct from that of the Tabulata of the underlying Silurian. In the light of synchronous sequences, the similarity of morphological features of the walls of Favositinae acquire great importance. This evidence may be used for subdivision of the Lower Devonian and for long-range correlation.