Radiometric dating of the Tertiary volcanics in Lower Silesia, Poland. VI. K-Ar palaeomagnetic data from basaltic rocks of the West Sudety Mountains and their northern foreland

Abstract

This article presents the sixth and final contribution in a series of papers focused mainly on the K-Ar dating of the Oligocene and Neogene (Miocene and Pliocene) intraplate basaltic volcanics of the Lower Silesia, SW Poland. The present paper includes 22 new K-Ar dates from the West Sudety Mountains and their northern foreland. The K-Ar dates range from 30.7 to 22.2 Ma. The data are supplied with geological description of the sampled outcrops, petrographic, geochemical and palaeomagnetic data of the analysed samples. Palaeomagnetic investigation confirmed the existence of two important volcanic episodes distinguished already in 1997: the reversed polarity Odra Event (mean age 28.2±1.2 Ma), and the normal polarity Gracze Event (mean age 26.28±1.8 Ma).