Rozkłady spękań ciosowych w płaszczowinie magurskiej polskich Karpat zewnętrznych w świetle analizy statystycznej

Abstract

DISTRIBUTION OF JOINTING WITHIN MAGURA NAPPE, WEST CARPATHIANS, POLAND, IN THE LIGHT OF STATISTICAL ANALYSIS Summary The paper focuses on statistical parametres of joint sets identified within Upper Cretaceous through Oligocene flysch strata in the Magura Nappe, Outer West Carpathians, Poland. More than 120 stations, each of them numbering 100 measurements, have been studied. The joint set distributions have been described by computed normalized eigenvalues plotted on diagrams devised by Woodcock (1977), as well as by parametres that denote fabric strength (C) and girdle/cluster tendencies ofthe distributions studied (K). The fabric strength measures (C) attain higher values, indicating better-defined joint fabric, within progressively younger strata, as well as when proceeding from the west to the east. Such a tendency could result from the clockwise, eastward-directed, diachronous migration of Miocene folding along the Carpathian arc; it could also suggest that older, i.e. Upper Cretaceous, strata might have been affected by at least two episodes of folding.