Trzeciorzęd okolic Korfantowa

Abstract

THE TERTIARY IN THE KORFANTÓW VICINITIES (Opole Silesia)

During the prospection drillings for brown coal in the Korfantów vicinities, Opole Silesia, the Tertiary fresh-water deposits (Pliocene, and Miocene ones), about 100 m thick, have been encountered .in the substratum of the Quaternary which in this area amounts from 2 to 32 m in thickness. The sediments discussed here do not represent a complete Tertiary profile in the region under study, since in a bore hole at Wawrzencowice, about 10 km to the east, approximately 200 m thick Tertiary fresh-water deposits have been found to rest on the marine and brackish sediments of Tertiary age.

Analysis of gravimetric map and geological materials of bore holes show that the region of Korfantów is situated in a tectonical graben-like depression.

The process of formation of brown coal In this basin, deepening in the course of Tertiary time, has been hindered by very violent accumulation of clastic material originating from the adjacent mountains.

The Tertiary sediments occurring in the vicinities of Korfantów are represented mostly by grey green, grey and variegated clays, more or less arenaceous, with calcareous (marly) concretions in the lower part, as well as by silts and arenaceous lenses, also lenses of sands with gravels. Considerable thickness of arenaceous and arenaceous-gravelly lenses occurring within the claysediments, proves the great part of river sediments in lake deposits.

In the drilling cores of the two bore holes well preserved prints of plant leaves with pellicles have been found in silts and arenaceous clays ·at the depth from 45,6 m to 51,7 m at Śnicz and from 85,4 m to 87,6 m at Stara Jamka. J. Bobrowska, who has determined the flora in question, regards·the floral assemblage from the bore hole Stara Jamka as that to be best compared with the Middle Miocene flora from Zalesice, near Wiśniowiec (H. Czeczott, 1951). On the other hand, the floral assemblage found in the bore hole at Śnicz, comprises a series of species, the age of which is usually referred to the Upper Miocene .(H. R. Goeppert, 1855, J. Lilpop, 1924). However, in the ,bore hole at Śnicz a specimen of Quercus kubini (K o v.) C ze c zo t t has also been found, which does not occur, as it is commonly known, later than at the Middle Miocene time.

Description of the determined flora is given in the text and several better preserved specimens are ·shown on Tab. I and Tab. II.