Abstract

Devonian rocks (together with unconformably overlying Carboniferous formations) fill the Lvovian Palaeozoic depression, situated in the western part of the Volyno-Podolia region.

The Lower Devonian is represented by terrigenous red beds up to 7000 metres in thickness, with the remains of terrestrial flora and a fish fauna. The Middle Devonian is made up of terrigenous and carbonate sediments, up to 250 metres in thickness. The Upper Devonian is mainly carbonates over 7000 metres in thickness. For the Middle and Upper Devonian, the brachipods are the most important fossil group.

In the Early Devonian the formation of a compensating depression was initiated in front of the Caledonian folded structures at the margins of the platforms. This depression was filled with continental sediments of Old Red Sandstone facies. In the Middle Devonian the territory was covered by sea, which left lagoonal marine sediments. In the Late Devonian, mainly shallow marine sediments were deposited; only at the close, in the Famennian Stage, did regresssive lagoonal and subcontinental sediments accumulate.

Economic minerals, connected with sediments of Devonian age, include copper mineralization in the Lower Devonian, sandstones and dolomites of the Lower and Middle Devonian, used as building materials; and combustible gas, found at the base of the Middle Devonian.

During the greater part of the Devonian Period the region was a link between the basins of the Russian platform and the geosynclinal region to the west. Therefore, the correlation of coeval sediments of these adjacent territories permits the solution of a number of questions of general Devonian stratigraphy for the whole of the Russian platform.