Marine Upper Paleozoic Deposits of Arctic: ABSTRACT

Abstract

Marine upper Paleozoic deposits within the Arctic are widespread in Novaya Zemlya, the Pechora basin, Taimyr, the Verkhoyansk basin, northeastern USSR, Spitsbergen, Greenland, the Arctic Archipelago of Canada, and Alaska. The upper Paleozoic in all these regions includes not only Permian, but also widespread middle-Upper Carboniferous deposits. Fossils of middle-Upper Carboniferous deposits in the western Arctic sector (Pechora basin, Novaya Zemlya, Spitsbergen, Greenland, Arctic Archipelago of Canada) do not generally differ from those of the corresponding deposits of the Urals, Russian platform, and other regions of the tropic paleozoogeographical province. The middle-Upper Carboniferous fauna of the eastern Arctic sector (Taimyr, Verkhoyansk basin, northeastern USSR) is marked by complete lack of fusulinids, colonial corals, and some other groups. This fauna contains several endemic genera of brachiopods and ammonoids (Yakutoproductus, Orulgania, Taimyrella, Yakutoceras, and others). This fact allows one to consider the region as a boreal zoogeographical province. Within this region the Bashkirian and Moscovian stages and the Upper Carboniferous are tentatively recognized. The boundary between the Carboniferous and the Permian is drawn at the appearance of Yakutoproductus verchoyanicus, which does not correspond to the base of the Schwagerina zone. A westward shift of the boundaries of the boreal province occurred in the Permian. At the beginning of the Late Permian this province covered all the territory considered. In the Early Permian two stages may be distinguished and traced here: the Asselian within the Schwagerina zone and the Artinskian, within the limits established by A. P. Karpinskiy. The Lower-Upper Permian boundary is determined by the appearance of brachiopod genera such as Grumantia, Megousia, and Pterospirifer, and by flourishing pelecypods of the genera Prosrassatella, Prooxytoma, Pseudobakewellia, and a development of the genus Kolymia. This renovation of the fauna is connected with a general transgression of the seas and establishment of short-term connections between the Arctic and Tethys seas. The Pay-Khoy and Kazanian stages may be distinguished in the Upper Permian. In the Arctic, ammonoids became extinct at the end of the Pay-Khoy stage, and brachiopods in the middle of the Kazanian. End_of_Article - Last_Page 2510------------