Wstępne wyniki badań egzotyków warstw inoceramowych serii skolskiej z niektórych stanowisk Karpat przemyskich i birczańskich

Abstract

RELIMINARY RESULTS OF STUDY ON EXOTICS FROM THE INOCERAMIAN BEDS OF THE SKOLE SERIES, OF SEVERAL SITES IN THE PRZEMYŚL AND THE BIRCZA CARPATHIANSThe author presents the preliminary results of his study on exotics from the upper part of the inoceramian beds; collected in several sites of the Przemyśl and the Bircza Carpathians. The exotics originate from three different localities.The first assemblage consisting only of sedimentary rocks, originates from the Przemyśl-Krzemieniec area. In this group the author has distinguished: yellowish quartz sandstones with residual calcitic matrix; grey, finegrained sand-stones; brown, organogenic-oolitic limestones; cream coloured, organogenic-oolitic limestones; grey, arenaceous limestones with spicules of siliceous sponges; grey, arenaceous, foraminiferal-algal limestones and light coloured marly spiculose-radiolarian-foraminiferal limestones.The second assemblage originates from the Przemyśl-Zielonka area. There are represented here: rough sandstones (-HCl); reddish-brownish, oolitic limestones; light coloured, creamy-white organogene-oolitic limestones; cream coloured dolomitic limestones of subclastic structure; cream coloured limestones with red coating of sub clastic structure; yellowish, arenaceous, aglauconitic marls; arenaceous deposits filling fissures in limestones, and dark hornstones of bluish tint.The third discussed site of exotics is at Wola Korzeniecka, near Bircza. In the material, there are represented sedimentary, volcanic and metamorphic rocks, viz.: finegrained quartzsandstones; light brown organogenic limestones with crinoids, foraminifers and calpionellae; ashen-grey limestones as above; white limestones of "biancone" type; greenish limestones containing Calpionella alpina, C. elliptica and other forms; grey foraminiferal-spiculose-radiolarian siltstones; yellowish, marly foraminiferal-spiculose radiolarian limestones with 2-leruf Globotruncana; grey-white, marly foraminiferal-spiculose radiolarian limestones with Globotruncana lapparenti lapparenti, G. lapparenti tricarinata, G. marginata a.o. Among volcanic rocks there are represented: andesite of pilotaxitic structure; andesite of polyphyr structure; andesite of a structure resembling spilites; red dacite of apohialopylitic structure; greenish, spotted lava agglomerate, and pearl-grey crystal tuffoid. Among metamorphic. rocks there are grey gneisses.A fairly distinct difference may be observed between exotics derived from the Przemyśl area and those from the vicinity of Bircza. In the area of Przemyśl the Tithonian shows the Stramberg development, whereas in the Bircza region it is pelagic, with the features of Calpionella-type Tithonian. In the vicinity of Bircza the volcanic rocks are relatively numerous.In view of the development of the Tithonian, the exotics from the Przemyśl area would belong to the Kruhel zone .(comp. M. Książkiewicz,·1956), whereas those of the Bircza region, due to the pelagic Tithonian, rather to a more interior, southern zone. Another difference must be seen in the historical development of these zones, and in the genesis of the sediments in which the exotics occur. At that time, the Kruhel zone presumably formed the northern margin, of the Carpathian geosyncline. In the Bircza zone, no klippen of the older pre-Flysch substratum appear at the surface, and the exotics occur in the secondary deposit there. Compared with the sites of the present-day occurrences of exotics, the Bircza zone of alimentation was, in general, ,probably in a more northwestern position. The moment of appearance of the exotics should probably be linked with the phenomena of diastrophism of that time, what is proved by the occurrence of diversified volcanic rocks in the Bircza region.