Abstract The West Sudetes (NE margin of the Bohemian Massif) consist of a complex mosaic of several tectonometamorphic units juxtaposed during the Variscan orogeny. The polyphase Variscan tectonothermal development of the West Sudetes was determined by 40 Ar/ 39 Ar ages of single grains and mineral concentrates. Late Famennian (359 Ma) mica ages from the high-grade Góry Sowie Block suggest continuous uplift after a Late Devonian high temperature-low pressure (HT-LP) event contemporaneous with the end of subduction-related high pressure-low temperature (HP-LT) metamorphism in the East Krkonoše Complex. Mid-Late Devonian high pressure events in the Krkonoše-Jizera Terrane and Orlica-Śnieżnik Dome are followed by coeval high temperature events between 345 and 335 Ma (Viséan). The latter are interpreted as consequence of uplift, and decompression during overthrusting of both complexes on their forelands. Subsequent small- to large-scale shear movements dated at around 325–320 Ma (early Namurian) affected the Orlica-Śnieżnik Dome, Krkonoše-Jizera Terrane, including the Intra-Sudetic Fault, and also the eastern Lusatian Granitoid Complex. They were accompanied by contemporaneous emplacement of the Krkonoše-Jizera pluton. The upper limit of the tectonometamorphic and magmatic activity is dated at 314–312 Ma (Namurian/Westphalian boundary). The final juxtaposition of the diversified tectonometamorphic units, which constitute the West Sudetes, took place in early Namurian times.

Abstract This study reports the Raman data for reduced carbonaceous matter (CM) in crystalline marbles, related to a determination of their provenance. Raman microspectrometry was tested on ‘graphitic’ marbles formed under different metamorphic conditions (regional v. contact) with various geological ages, and with distinct types of CM from the Bohemian Massif (Czech Republic). First, various modes of occurrence of CM were examined by optical microscopy (OM). The Raman results exhibited spectral variations of CM with different metamorphic grades and types. Several marble groups could be distinguished: (1) well-ordered CM/graphite of higher grade regional metamorphosed marbles; less graphitized metamorphosed organic matter (‘disordered’ CM); (2) low-grade regional metamorphosed rocks, and (3) contact metamorphosed marbles.