ASGP (2011), vol. 81: 115–131
RADIOMETRIC DATING OF THE TERTIARY VOLCANICS IN LOWER SILESIA, POLAND. VI. K-Ar AND PALAEOMAGNETIC DATA FROM BASALTIC ROCKS OF THE WEST SUDETY MOUNTAINS AND THEIR NORTHERN FORELAND
Krzysztof BIRKENMAJER1, Zoltán PÉCSKAY2, Jacek GRABOWSKI3, Marek W. LORENC4 & Paweł P. ZAGOŻDŻON5
1 Institute of Geological Sciences, Polish Academy of Sciences, Cracow Research Centre, Senacka 1, 31-002 Kraków, Poland, e-mail: ndbirken at cyf-kr.edu.pl 2 Institute of Nuclear Research, Hungarian Academy of Sciences, Bem tér. 18c, 4001 Debrecen, Hungary, e-mail: pecskay at namafia.atomki.hu 3 Polish Geological Institute – National Research Institute, Rakowiecka 4, 00-975 Warszawa, Poland, e-mail: jgra at pgi.waw.pl 4 Institute of Landscape Architecture, Wrocław University of Environmental and Life Sciences, pl. Grunwaldzki 24a, 50-363 Wrocław, Poland, e-mail: marek.lorenc at up.wroc.pl 5 Institute of Mining, Wrocław University of Technology, pl. Teatralny 2, 50-051 Wrocław, Poland, e-mail: Pawel.Zagozdzon at pwr.wroc.pl
Birkenmajer, K., Pécskay, Z., Grabowski, J., Lorenc, M. W. & Zagożdżon, P. P., 2011. 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. Annales Societatis Geologorum Poloniae, 81: 115–131.
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).
