Kurzfassung (Abstract)

This study aimed to put constraints on regional and/or global environmental changes, which took place during the Frasnian-Famennian transition by using a geochemical multiproxy approach. The investigation of several key European Frasnian-Famennian boundary sections (Coumiac and la Serre, Montagne Noire, France; Steinbruch Schmidt/Branau, the drilling Büdesheimer Bach/Prümer Mulde, Germany; Kowala Section, Holy Cross Mountains, Poland) brings new geochemical evidences which emphasize the role of tectono-magmatic processes, like volcanism, hydrothermalism and major tectonic movements in the development of the particularities of the Kellwasser Horizons deposited close to the southern shores of Laurussia and the northern parts of Gondwana. Finally the observed enrichment in metals, in nutrients and the lowering of the oxygen level in the seawater during the deposition of the Kellwasser Horizons, coupled with an enhanced bacterial activity, must have played a decisive role in the major biotic crisis occurring at the Frasnian – Famennian transition. In parallel to this classical approach, the trace element contents in authigenic pyrites along the Büdesheimer Bach core were recorded in order to test the capability of this method as a source for supplementary information on depositional conditions. The results of this study contribute to the small number of existing publications dealing with the potential of trace element pattern of pyrite as an indicator for depositional conditions.