Source rocks of detrital biotite from Lower Permian sandstones of the Krkonoše Piedmont Basin northern margin

Geoscience Research Reports 46, 2013 (GRR for 2012), pages 45–50

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Abstract

Well preserved detrital biotite grains with almost no alteration features were found in Lower Permian alluvial sandstones of the Krkonoše Piedmont Basin northern margin. This is interpreted as short transport directly from primary source rocks with no recycling of detritic material. Biotite grains show high compositional variability: Lower Rotliegend samples have composition similar to Krkonoše-Jizera Crystalline Complex orthogneisses, while Upper Rotliegend samples contain also significant amount of F-rich biotites - annites, which probably comes from greisens or highly fractionated orthogneises. Upper Rotliegend (03-42 Trutnov, 03-14 Liberec, 03-23 Harrachov) tectonic reactivation of the basin could thus be connected with exhumation of deeper parts of the the Krkonose-Jizera Complex - fractionated orthogneises, which crops out close to Jizera- Krkonose Pluton.