Paleobiogeographic Zonation of Carboniferous in Northern Hemisphere: ABSTRACT

Abstract

A Siberian biogeographic realm with the fauna and flora of a temperate-cool climate, and a Mediterranean realm with the fauna and floras of a tropical-subtropical climate existed in the Northern Hemisphere during all of the Carboniferous. There were no ammonites during the Tournaisian in the Siberian realm and the corals and brachiopods were less varied than in the Mediterranean one. Endemic brachiopod species are typical for the Siberian realm. The Siberian realm included the Verkhoyansk, Kolyma, Taimyr, Tunguska, and Chersk provinces. The Verkhoyansk and Kolyma provinces, with rich faunas, coincided with the shelf of the Kolyma massif and the Siberian platform that was covered by calcareous silt. Verkhoyansk and Kolyma were separated by the Chersk province which had a poor fauna typical of deep-water basins. The Tunguska province differed from the Taimyr province in variety of tournayellids and endothyrids present and in poverty of brachiopods, but is similar to Kuznetsk province in poverty of brachiopods. Only multifacial foraminifers remained among the Visean foraminifers of the Siberian realm. Ozaweinellidae became scarce during the time of Yasnaya'Polyana and Okhoye deposition. Endothyridae became scarce but archaediscids increased during the time of Serpukhov deposition. Corals were represented by impoverished complexes. The Siberian species constitute a large percentage of the brachiopods. During the Visean, the Siberian realm spread over the Omolon, Zaysan-Mongol, and Kazakhstan provinces. During the Serpukhov deposition, the Kolyma and Verkhoyansk provinces joined, and the Chersk province was eliminated as a result of structurally controlled facies changes. At the same time, the Tunguska and Kuznetsk provinces disappeared as a result of the continuing marine regression. In Late Carboniferous (Samodiye-early Bashkirian) time, the Archaediscidae continued to dominate in the seas of the Siberian realm; there were many local species and genera among the brachiopods. The fauna of that time was especially abundant in the Taimyr province, from where an arm of the sea extended south to the seaway in the Ob'-Zaysan geosyncline. East of the Kolyma massif, the Anyuysk province existed. Beginning with Kulom deposition (late Bashkirian), arenaceous foraminifers continued to develop in the seas of the Siberian realm; fusulinids, archaediscids, and other forms were completely absent. The brachiopods were represented mainly by endemic species and genera. The goniatites (including species common with those of Northern America and the Urals) were represented by Siberi n endemic species and genera. The most essential differences at that time took place between the faunas of Verkhoyansk-Kolyma province with its foraminifers, goniatites and brachiopods and Mongol-Okhotsk province where foraminifers and goniatites were absent. Not long before the end of the Carboniferous the goniatites had disappeared from the seas of the Siberian realm. At the same time, most brachiopods had become extinct. In the western part of the Arctic the Barents-Franklinian area had an impoverished fusulinid and goniatite fauna that differed from the faunas in the Mississippian basins of North America. End_of_Article - Last_Page 2513------------