Ukształtowanie powierzchni podłoża i geologia kenozoiku południowo-wschodniej części bloku przedsudeckiego

Abstract

Scharakteryzowano ukształtowanie powierzchni podłoża podkenozoicznego na obszarze SE części bloku przedsudeckiego na podstawie danych geofizycznych. Opisano szereg form o charakterze zrębów i rowów tektonicznych wypełnionych przez osady trzeciorzędowe. Przedstawiono główne cechy zmienności litologicznej sedymentacji trzeciorzędowej oraz ukształtowanie erozyjnej powierzchni podczwartorzędowej BEDROCK SUFRACE MORPHOLOGY AND GEOLOGY OF THE CENOZOIC OF SOUTH-EASTERN FORE-SUDETIC BLOCK Geological interpretation of results of geophysical surveys from SE part of the Fore-Sudetic block made it possible to characterize morphology of Cenozoic bedrock and its block tectonics, lithology of Tertiary deposits and main features of the relief of Quaternary subsurface between the margin of the Sudety Mts and Przyłęk – Ząbkowice Śląskie – Ziębice – Złoty Stok towns. The course of main elements of the relief of Cenozoic bedrock appears different from that hitherto assumed. A narrow furrow with axis plunging to SE is infilled with Tertiary deposits and runs along the marginal Sudetic fault. The furrow belongs to a regional structure known as Fore-Sudetic trough, from which it is separated by longitudinal depressions marked in Cenozoic bedrock, i.e. Ziębice and Suszki-Grochowiska furrows. The two latter furrows divide a latitudinal structure known in the literature as Braszowice horst (J. Oberc, 1972), into several separate tectonic horsts. Meridionally trending forms predominate north of the Fore-Sudetic trough. The distribution of bedrock forms is mainly determined by two main dislocation systems extending from the Sudetic block without any changes in direction or nature, and trending NW-SE and from NNE-SSW to NE-SE, respectively.The paper presents detailed characteristics of marginal Sudetic fault and its amplitude. Tertiary deposits attain their maximum thickness, 500 m, in the Fore Sudetic trough north-east of Złoty Stok. Clay deposits, silts and possibly also volcanic tuff predominate in lower part of the profile, whilst sandy-gravel horizons corresponding to flat piedmont cones originating at· the margin of uplifting Sudetic block predominate in the upper part. The top of Tertiary deposits is delineated by erosional surface with relatively small denivellations. The nature and course of main forms of relief of Quaternary bedrock are discussed.