Sedymentacja babickich warstw egzotykowych w Karpatach Przemyskich

Stanisław Bukowy


Remarks on the sedimentation of the Babica Clays

The Babica clays form a part of the exotic beds appearing at the boundary of the Cretaceous and the Tertiary of the Marginal Carpathians in the environs of Rzeszów. The exotic beds consist of sandstones, conglomerates, shales, siltstones and clays. The common feature of these deposits is the presence of numerous exotics in them.. The Babica clays are situated in the top of the Inoceramian beds consisting of greenish, marly shales alternating with laminated sandstones and graded conglomerates. The orientation of current hieroglyphs (flow marks) and pebbles points out to the transport from NW towards SE. The Babica clays apperar as large flat lenses consisting mainly of dark pelite in which are situated pebbles of exotic rocks of various size up to1 2,5 cm long, and fragments of the beds torn away from the base. This deposit contains a shallow water macro- and microfauna and also Lithothamnia, although it occurs in clays with a microfauna pointing out to a deeper sea. From the orientation of scarcely scattered pebbles and from the erosion traces on their basement one should assume that this material was transported as a slide of unconsolidated sediment (mud flow) from N towards S. Over the clays of Baibica there are situated diagonally bedded sandstones, graded conglomerates with exotics, and still higher, laminated sandstones. In the conglomerates of the Inoceramian beds, besides the quartz there occur pebbles of porphyry and of Upper Jurassic limestones. In the clays of Babice the pebbles of the Younger Paleozoic rocks, including coal, are in majority. In the conglomerate over the clays, on the other hand, there are besides, quartz, almost exclusively slates and quartzites. From this succession we may trace the structure of he neighbouring land and the progress of erosion. The exotics differ between each other by the degree of roundness and weathering; some show traces of river transport others show roundness acquired rather in the littoral region. Some pebbles of the Carboniferous and Devonian limestones, before they reached the slide, were subject to weatering and have on the surface the weathered out fossils. This material is differentiated by the distance of transport: the pebbles and the unrounded fragments of the Jurassic limestones and Carboniferous coal, being not resistant to the river transport, come apparently from a nearby situated land. The pebbles of the Carboniferous limestones, dolomites and the Devonian limestones, on the other hand were probably carried from inside the land.

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