Rysy powierzchni kaledonidów na obszarze przedgórza północnych Karpat na podstawie materiałów geologiczno-geofizycznych

Abstract

OUTLINES OF CALEDONID'S SURFACE IN THE NORTH CARPATHIAN FORELAND ON THE BASIS OF GEOLOGIC-GEOPHYSICAL MATERIALSSummaryAn attempt was made to determine the character of the surface of older formations - Pre-Cambrian and Cambrian - on the basis of the materials obtained from velocity logging made in deep bore holes. The configuration was given in time version 2 T, isochrones being plottet 0.1 sec apart, corresponding to 200 m in depth. The picture of the eastern part of the Carpathian foreland, where more drillings were made, is more detailed than that if the western part which illustrates the virtual scheme of the deep older basement. Numerous longitudinal and transversal dislocations were geophysically ascertained (eastern part) or determined on the basis of drill materials and on the geological interpretation of data. On account of feeble reconnaissance of the structure of the folded basement, additional dislocations should be expected to occur in the basement, as proved also by large dislocations observed in the Jurassic and Cretaceous formations. The analysis of the occurrence of oil and gas deposits suggests that a dependence exists between the configuration of the deep basement and direction of dislocations, mainly transversal dislocations, proving a considerable role played by the latter in the process of migration and accumulation. The picture here considered can, first of all, be of assistance in the further researches of the older basement using seismical methods. Due to a fact that the scheme gives the surface of the folded older formations of Pre-Cambrian land Cambrian age, it should be regarded as a scheme of the so-called Caledonids, which are the basement for the sedimentary formations in the area of the North Carpathian foreland.