ASGP (2017), vol. 87: 1–12
ORIGIN OF PARAUTOCHTHONOUS POLISH MOLDAVITES– A PALAEOGEOGRAPHICAL AND PETROGRAPHICAL STUDY
Krzysztof SZOPA (1), Janusz BADURA (2), Tomasz BRACHANIEC (1), David CHEW (3) & Łukasz KARWOWSKI (1)
1) Department of Geochemistry, Mineralogy and Petrography, Faculty of Earth Science, University of Silesia in Katowice, Będzińska 60, 41-200 Sosnowiec, Poland; e-mails: krzysztof.szopa at us.edu.pl, tomasz.brachaniec at o2.pl, lukasz.karwowski at us.edu.pl
2) Polish Geological Institute – National Research Institute, Lower Silesian Branch in Wrocław, al. Jaworowa 19, 53-122 Wrocław, Poland; e-mail: janusz.badura at pgi.gov.pl
3) Department of Geology, School of Natural Sciences, Trinity College Dublin, Dublin 2, Ireland; e-mail: chewd at tcd.ie
Szopa, K., Badura, J., Brachaniec, T., Chew, D. & Karwowski, Ł., 2017. Origin of parautochthonous Polish moldavites – a palaeogeographical and petrographical study. Annales Societatis Geologorum Poloniae, 87: 1–12.
Abstract: In this article, the most recent moldavite discoveries in Poland and their host sediments are characterised and discussed. They were discovered at Lasów, located about 8 km north of Zgorzelec (Poland) and Görlitz (Germany), about 700 m from the Polish-German border, close to the Lusatian Neisse (Nysa) River. The tektites were collected from Vistulian (Wiechselian) glacial age sand and gravel of a closed quarry pit, associated with the river terraces. In the Lasów area, the moldavite-bearing sediments are Pleistocene in age and represent Lusatian Neisse terrace deposits. They were redeposited from the upper part of the drainage basin of the Lusatian Neisse, probably washed out from the Miocene sediments that filled the Zittau Depression, the Berzdorf–Radomierzyce Depression, the Višňová Depression and the tectonically uplifted Izera Mts. and Działoszyn Depression. The erosion of Miocene deposit occured on a large scale in the uplifted foothills of the Upper Miocene Izera, Lusatia and Kaczawa complexes. The sediment cover was removed from the Działoszyn Depression. The drainage basin of the Lusatian Neisse is the area where moldavites were formed by the Nördlinger Ries impact. The source area of moldavite is the same for the Miocene deposits around Gozdnica, as well as for the Pleistocene sediments at Lasów.
Manuscript received 29 October 2016, accepted 3 May 2017