The 40Ar/39Ar cooling ages of white micas from the Jegłowa Beds (Strzelin Massif, Fore-Sudetic Block, SW Poland)

Abstract

The metamorphic rocks of the Strzelin Massif, in the Fore-Sudetic Block, underwent polyphase tectonothermal evolution terminating with late orogenic gravitational collapse. These rocks recorded Early Permian cooling ages in the range of 279-285 Ma, obtained on white mica concentrates derived from metasediments of the Jegłowa Beds. The obtained results correspond to the youngest group of ages presented by Maluski et al. (1995) from the northern part of the Jeseník Mts, the Moravo-Silesian Zone of the East Sudetes. They suggest very low exhumation rate.