Charakterystyka osadów piaskowca trzcinowego na Niżu Polskim

Abstract

DESCRIPTION OF REED-SANDSTONE DEPOSITS IN THE POLISH LOWLAND AREASummaryBased on geological materials from about 200 bore holes the author presents lithological development, bases of stratigraphy, and facial distribution of the reed-sandstone in the Polish Lowland area. The reed-sandstone is one of the three members of the Upper Keuper. This member has been distinguished on the basis of lithological evidences. Palynological examinations carried on in the last years will maybe yield more accurate stratigraphical information, as well. Megaspores found in these deposits, i.e. Biharisporites harrisi  R e i n h a r d t et F r i c k e, and a spore-and-pollen assemblage: Ovalipollis breviformis K r., Aulisporites astigmosus (L e s c h.) K 1 a u s, Annulispora microannulata   de J e r s e y, Aratrisporites paraspinosus K l a u s., Leschikisporis adunctus (L e s c h.) P o t., Camarozonosporites (C.) rudis (L e s c h) K l a u s are characteristic of the member under consideration. Among fauna representatives are found banal and long-lived forms Anoplophora lettica var. ovalis Z e l l e r., A. brevis S c h a u r., A. lettica Q u e n s t., Myoconcha gastrochaena D u n k e r., and Estheria lxitexa S a n d b. The thickness of the reed-sandstone series ranges from 40 to about 130 metres (Fig. 1). It is characterized by a considerable lithological variability both m vertical profile and in horizontal extent (Fig. 2, Fig. 3). Along with the almost only arenaceous deposits there are found here also clayey and clay-mudstone ones. The sedimentary basin of the reed-sandstone within the Polish Lowland area resembled a wide flat water pool, into which flowed all rivers from south, south-east end north (Fig. 2). The distribution of facial zones of the reed-sandstone in the western part of the Pomeranian trough, and within the monocline area in the region of Pomorsko and Leśna, points to the occurrence of well developed deltas in this area, characterized by some arenaceous tongues, with several zones of quiet sedimentation between them.