Diatomowe skały krzemionkowe z eocenu dolnego Karpat Borysławskich

Abstract

SILICEOUS DIATOMITE ROCKS IN THE LOWER EOCENE OF THE BORYSŁAW CARPATHIANS

The author reports the discovery of siliceous diatomite rocks in the variegated Supra-Jamna horizon (Lower Eocene) in the area of the Borysław Carpathians. The siliceous rocks of this locality have been repeatedly described from a number of sections existing in the region of the Eastern Carpathians; usually they were called hornstones. Macroscopically these rocks resemble the green radiolarites from the Middle Cretaceous of the Western Carpathians.

In thin sections prepared from these rocks there may be observed a copious. accumulation of diatoms of 0.04 to 0.1 mm. size. In their great majority they belong to Triceratiinnae and Hemiaulinae, especially to genus Eutriceratium and to subgenus Euhemiaulus. These diatoms are marine forms. Their planktonic character might explain the wide spread of the siliceous rocks within the Lower Eocene in the area of the Eastern Carpathians