The geological structure of East Poland and West Russia: A summary of recent discoveries

Abstract

Summary Recent investigations have yielded the following results. The extensive Ukrainian granitic massif has been traced some 30 miles farther north beneath the Pripet Marshes, and the primary Archaean massif must have been at least twice as large las the present one. The Donetz Basin, instead of being relatively small and enclosed, proves to be part of a great trough extending northwestwards for at least 1000 miles to the Pripet Marshes. In the middle of this North Ukrainian trough several Permian salt domes have been detected. The Lower Palaeozoic in Podolia and Volhynia differs in some respects from that of the Baltic countries. The Devonian is more uniform in the two regions. As the younger Palaeozoic rests directly on the granite, the impression is given of two Lower Palaeozoic provinces separated by an Archaean belt. Three new Carboniferous deposits have been discovered; one of Moscow facies with coal in Polesia (under the Pripet Marshes), one in Volhynia with coal near to anthracite and one in Lithuania without coal measures. The last-mentioned would appear to be a prolongation of the Danzig-Lwow trough. Of later connexions between the Russian and the West European basins that pass more or less through Poland, probably none existed in the Triassic period. The Upper Cretaceous seas were very extensively connected in Cenomanian times; the connexion was narrower in the Turonian and apparently absent in Senonian time. In the Oligocene it followed approximately the same line as in the Cretaceous, with a slight displacement to the south. The youngest connexion, in the Upper Miocene, is much farther south. The relation between East and West Europe is much more complicated than has been supposed and Tornquist9s hypothetical line does not, in fact, exist. The big syncline passing from Danzig to Lwow is related only to the West European structure although situated east of the hypothetical line. The Lithuanian basin appears to be a side branch of that trough; here the western structure passes slowly into the Russian type. The extensive North Ukrainian basin perhaps marks more completely the line of separation between the two main parts of Europe.