Południowo-zachodni brzeg platformy wschodnioeuropejskiej w Polsce w świetle wyników badań magnetycznych

Abstract

SW MARGIN OF THE EAST-EUROPEAN PLATFORM IN POLAND IN THE LIGHT OF NEW MAGNETIC DATA Summary In the years 1957-1958, the authors delineated the course of SW margin of the East-European Platform, previously drawn in a generalized way with reference to results of surface geological studies (W. Teisseyre) and innumerous magnetic measurements (A. Tornquist, S. Pawłowski), and known as the Tornquist or Teisseyre Line. In attempt made by the authors, the course of the Platform margin was delineated with reference to the places of maximum concentration of isanomals of vertical component of the Earth magnetic field in their magnetic map of Poland in. the scale 1:1 000 000, compiled on the basis of provisionally compiled results of regional magnetic surveys. The results of regional magnetic surveys were subsequently reanalysed by K. Karaczun and his team after reduction to a common level and epoch and with the use of newly elaborated formula for normal field. This made it possible to compile a new magnetic map of Poland in the scale 1:500 000. With the use of basic materials from the above mentioned study, the authors calculated mean absolute values of horizontal changes of vertical component of the magnetic field. The calculations were made using a method proposed by A. Dąbrowski. Lines connecting maximum values of that parameter gave the projection of upper margins of deep crustal fractures corresponding to SW margin of the East-European Platform at the surface. Except for the areas of the Koszalin and Nisko-Lubaczow-Przemyśl, the differences between the course of the Platform margin as delineated in the years 1957-1958 and at present (i.e. with reference to mean absolute values of horizontal changes) are not greater than about a dozen kilometers. Attention should be paid to numerous breaks, bends and shifts of deep fractures connected with the Platform margin as well as accompanying ones. The delineated boundary may be treated as corresponding to the Tornquist-Teisseyre Line in the section from Koszalin in the north to SE state boundary. In the Baltic Sea, the course of the Platform margin seems to be turning SW of that originally assumed by W. Teisseyre and A. Tornquist and their followers.