Wstępna charakterystyka strukturalno-petrograficzna fyllitów z Podmąchocic w regionie łysogórskim Gór Świętokrzyskich

Abstract

Preliminary structural-petrography characteristic of phyllite from Podm¹chocice in the Łysogóry Unit of the Holy Cross Mts.S u m m a r y. Four tectonic deformation events are recorded in the Middle Cambrian rocks from Kamecznica Podmąchocicka. The D1 event took place in Cambrian and originated from tremor. Its structural record includes synsedimentary folds and seismites. The D2–D3, and most probably also D4, events resulted from progressive deformation produced by tectonic compression initially from NE and then NNE direction. Folding was accompanied by green facies metamorphism, which resulted in development of phyllites. Composition and characteristic deformations of minerals suggest that they were produced in temperature ranging from 300º to 400ºC and differential pressure above 1.7 kbar (170 MPa). The combined deformation and metamorphism resulted in three generations of foliation — S1 to S3 defined by crenulated cleavage planes. New blasts of quartz, small scale muscovite (sericite), chlorites and sporadically biotite grew within these cleavage planes. Deformations and metamorphism took place after the Middle Cambrian, but before the Late Silurian. It is indicated by presence of the quartzitic sandstone pebbles in the Miedziana Góra Conglomerates.