ASGP (2002), vol. 72: 119-129

RADIOMETRIC DATING OF THE TERTIARY VOLCANICS IN LOWER SILESIA, POLAND. II. K-Ar AND PALAEOMAGNETIC DATA FROM NEOGENE BASANITES NEAR LĄDEK ZDRÓJ, SUDETES MTS

Krzysztof BIRKENMAJER (1), Zoltán PÉCSKAY (2), Jacek GRABOWSKI (3), Marek W. LORENC (4) & Paweł P. ZAGOŻDŻON (5)

(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 moon.atomki.hu
(3) Polish Geological Institute, Rakowiecka 4, 00-975 Warszawa, Poland; e-mail: jgra at pgi.waw.pl
(4) Institute of Geological Sciences, Polish Academy of Sciences, Sudetic Geology Department, Podwale 75, 50-449 Wrocław; e-mail: mwlorenc at twarda.pan.pl
(5) Faculty of Mining, Wrocław University of Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland, e-mail: Pawel.Zagozdzon at ig.pwr.wroc.pl

Birkenmajer, K., Pécskay, Z., Grabowski, J., Lorenc, M. W. & Zagożdżon, P. P., 2002. Radiometric dating of the Tertiary volcanics in Lower Silesia, Poland. II. K-Ar and palaeomagnetic data from Neogene basanites near Lądek Zdrój, Sudetes Mts., Annales Societatis Geologorum Poloniae, 72: 119-129.

Abstract: K-Ar dating of Cenozoic basaltic rocks (one plug and two lava flows) in the Lądek Zdrój area, Sudetes Mts, Poland (50.5°N, 17°E), has established their Neogene (Messinian-Zanclean) ages: from 5.46 to 3.83 Ma. They are the youngest manifestations of the Cenozoic vulcanicity in the Polish part of the Bohemo-Silesian Belt. According to new petrological and geochemical data, the studied rocks belong to basanites which display slightly differentiated mineral and chemical composition between the exposures. The basanites were magnetized most probably in one or more than one normal subchrons during middle part of the reversed Gilbert chron (between 4.18 and 5.23 Ma).