BALANOGLOSSITES-DOMINATED ICHNOFABRICS AND DIAGENETIC OVERPRINT IN THE EARLY EMSIAN LIMESTONE-DOMINATED SUCCESSION OF THE PRAGUE SYNFORM

The ichnofossil record of the early Emsian limestone-dominated succession in the Prague Synform, including the Bohemian Graptolite Event beds, was studied with a focus on ichnofabric development and its sedimentological and diagenetic implications. The studied interval yields a diverse ichnoassemblage comprising Balanoglossites, Zoophycos, Planolites, Taenidium, Phycosiphon, Trichichnus, Polykladichnus, Caulostrepsis, and possibly Trypanites, along with indeterminate biodeformational structures. The trace fossil distribution and fabric arrangement indicate a combined depositional regime characterized by episodic turbiditic influx followed by periods of relative quiescence. Some ichnological features, such as the co-occurrence of Zoophycos and Trichichnus, are shared between the Bohemian Graptolite Event interval and the uppermost part of the Dvorce-Prokop Limestone, suggesting similar environmental conditions, likely influenced by reduced oxygenation. Notably, the slightly nodular (“knobby”) structure of the studied limestones is closely linked to the presence of a Balanoglossites-dominated ichnofabric. This ichnofabric also significantly influenced subsequent diagenetic pathways, including selective dolomitization and silicification.