The uppermost Famennian – lowermost Tournaisian interval has been analysed in detail using biostratigraphy, sedimentology, magnetic susceptibility and geochemistry in a reference section of the relatively shallow carbonate ramp environment within the Pomeranian Basin. High-resolution biostratigraphic study, based on miospores, allows recognition of the standard western European lepidophyta–nitidus (LN) and verrucosus–incohatus (VI) zones, as well as the Convolutispora major Zone, a local Pomeranian equivalent of the European standard hibernicus–distinctus (HD) Zone. The sedimentary succession and specific phenomena recognized close to the Devonian/Carboniferous boundary, such as fluctuations in water column euxinia, wildfire evidence, relative sea-level changes and perturbations of the carbon cycle reflected by positive carbon excursions, display a pattern partly similar to that observed in many areas in Europe during the Hangenberg Event, although the Hangenberg Black Shale horizon is not developed here. These important microscale environmental perturbations were observed not only within the Famennian LN miospore Zone but in a wide interval between the LN and the lowermost local Convolutispora major miospore zones ( = lower part of HD standard miospore Zone). It is still uncertain whether the recognized event(s) were connected solely with the Hangenberg Event, which was possibly complex and multi-phased as is sometimes suggested, or whether they represent a succession of regionally limited, post-Hangenberg events. This question needs to be further investigated on broader stratigraphic and geographical scales.

A multidisciplinary correlation of the Devonian–Carboniferous (D–C) boundary sections from the Moravian Karst (Czech Republic) and the Carnic Alps (Austria), based on conodont and foraminifer biostratigraphy, microfacies analysis, field gamma-ray spectroscopy (GRS), carbon isotopes and element geochemistry, is presented in this paper. The study is focused on the interval from the Middle Palmatolepis gracilis expansa Zone (Late Famennian) to the Siphonodella sandbergi Zone (Early Tournaisian). In Lesní lom (Moravian Karst), a positive δ13C excursion in the Bisphatodus costatus – Protognathodus kockeli Interregnum from a distinct laminated carbonate horizon is correlated with a carbon isotope excursion from the Grüne Schneid section of the Carnic Alps and is interpreted as the equivalent of the Hangenberg black shales and a local expression of the global Hangenberg Event sensu stricto. Higher up at both sections, a significant increase in the terrigenous input, which is inferred from the GRS signal and elevated concentrations of terrigenous elements (Si, Ti, Zr, Rb, Al, etc.), provides another correlation tieline and is interpreted as the equivalent of the Hangenberg sandstone. Both horizons are discussed in terms of relative sea-level fluctuations and palaeoceanographic changes. Recent studies show that conodont biostratigraphy is facing serious problems associated with the taxonomy of the first siphonodellids, their dependence on facies and discontinuous occurrences of protognathodids at the D–C boundary. Therefore, the correlative potential of geochemical and petrophysical signatures is high and offers an alternative for the refining of the problematic biostratigraphic division of the D–C boundary.

A palynological study of the uppermost Famennian section from Kowala Quarry (Holy Cross Mountains, central Poland) allowed recognition of two miospore zones: LV (Retispora lepidophyta–Apiculiretusispora verrucosa) and LN (Retispora lepidophyta–Verrucosisporites nitidus). Based on palynology and sedimentology, the black shale within the upper part of the section is identified as equivalent to the Hangenberg Black Shale, which is known globally. This black shale contains compounds characteristic of photic zone euxinia, including isorenieratane and its derivatives. Such compounds are absent in the organic-poor marls and shales occurring below the LN Zone, and are present only as traces in the layers just above the black shale, indicating fluctuations in the oxygen minimum zone during uppermost Famennian sedimentation. Palynofacies show high amounts of amorphous organic matter and prasinophyte concentrations in the black shale, and a subsequent significant decrease of amorphous organic matter concomitant with a rapid increase of terrestrial input (mainly miospores with common tetrads) in the layers above the black shale. This supports the relatively rapid change in the taxonomic composition of phytoplankton caused by fluctuations of the chemocline. The whole succession corresponds to one sea-level rise and fall. The presence of high concentrations of peri-condensed polycyclic aromatic hydrocarbons and large amounts of small charcoal particles at the Hangenberg event horizon indicate the occurrence of wildfires. Such observations suggest that atmospheric O22 levels had exceeded the critical threshold of 13 %, above which wildfires may occur, by latest Famennian time.