W sprawie budowy geologicznej okolic Zalewu Szczecińskiego (głos w dyskusji)

Abstract

ON GEOLOGICAL STRUCTURE IN IN VICINITY OF THE SZCZECIN BAY

Summary

The present work is a polemics with the theses presented by M. Jaśkowiak-Schoeneichowa (1969). To this end, rich seismic and drilling materials have been used (Fig. 1).

A considerable importance of disjunctive tectonics is emphasized (Figs. 2-5). Deep zones of tectonic discontinuities affected both the process of sedimentation of the Zechstein-Mesozoic complex, and its present structural position. Thus, these discontinuity zones are real tectonic boundaries. On the other hand, the intersection boundary of the extent of the Cretaceous formations on the pre-Cainozoic surface, so far accepted as a conventional boundary between large structural units, is an insignificant secondary derivative of the synsedimentary and postsedimentary vertical block movements of the Zechstein substratum.
In the southern part of the area in study phenomena of salt tectonics are well developed. A salt pillow has been ascertained to occur at Wysoka Kamieńska (Fig. 6), a salt lens - in the region of Rekowo, and a zone of Zechstein salt flow along the Koplino fault (Fig. 5).
The geological evolution of the area, presented by M. Jaśkowiak-Schoeneichowa (1969) in the form of a diagram, is incomplete and simplified. The processes of subsidence were disturbed at the time of a set-back of sedimentation or even erosion (e.g. prior to Rhaetic or Portlandian). The uplifting process was not uniform, too. This was an oscillation process, begun in Coniacian at the earliest, and lasted till the end of the Cretaceous period, consisting probably in periodical (submarine?) outwash of the Upper Cretaceous deposits laid down before. Most considerable uplifting and removal of the main mass of the Lower Cretaceous and Jurassic deposits took place at the earliest Tertiary time.