Integrated palynological, organic and inorganic geochemical and petrographical methods have been used for deciphering the depositional redox conditions and character of organic matter of the Famennian Dasberg event horizon from the deep-shelf Kowala succession of the Holy Cross Mountains. The ages of the investigated samples have been established, using miospore data, as VF (Diducites versabilis–Grandispora famenensis) and LV (Retispora lepidophyta–Apiculiretusispora verrucosa) miospore Zones of the Middle/Upper Famennian. In the standard conodont zonation, this corresponds to the uppermost postera to lowermost praesulcata Zones. The presence of green sulphur bacteria biomarkers and dominance of small-sized framboids together with the presence of large framboids and low values of the U/Th ratio may indicate that during sedimentation of the lower Dasberg shale, intermittent anoxia occurred in the water column, or the anoxic conditions prevailed in the upper part of the water column, while the bottom waters were oxygenated, at least briefly. Deposition of the upper Dasberg shale was characterized by both bottom water and water column anoxia. The lack of acritarcha taxa from these intervals could have been due to anoxia in the photic zone. Moreover, organic content is high in those samples. There is no geochemical evidence for anoxia during sedimentation of the deposits sandwiched between the lower and upper Dasberg shales, or in the deposits which underlie and overlie both Dasberg shale horizons. The two discrete anoxic events are interpreted to be the result of major transgressions and the blooming of primary producers. Above the Dasberg shales, small fragments of charcoal and raised concentrations of polycyclic aromatic hydrocarbons are detected. This supports the presence of wildfires during deposition of shales just above the boundary of VF/LV palynological zones. Temperatures calculated from the fusinite reflectance values suggest that the charcoal was formed in low-temperature ground and/or surface fires. The typical marine character of sedimentation combined with the high proportion of charcoals suggests that wildfires were large-scale, and that there was intensive transport of terrestrial material. The main causes of intensive wildfires were a significant rise of O2 in the atmosphere and important progress in the land plant diversity during Late Devonian times. Palynofacies studies suggest that the transgression corresponds to the part IIf of the Late Devonian sea-level curve.

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.

The Duntulm Formation of the Bathonian (Middle Jurassic) Great Estuarine Group represents a marine-brackish lagoonal complex which was transgressively established on the drowned delta of the underlying Valtos Sandstone Formation. Duntulm Formation sediments accumulated in adjacent basins, the Sea of the Hebrides-and Inner Hebrides-basins. Litho-, bio-, and palynofacies analysis of these rocks show that the most distinctive lithologies, monotypic shell banks of the oyster Praeexogyra hebridica (Lithofacies 1), accumulated under variable, but distinctly marine conditions. Argillaceous carbonate muds (Lithofacies 2), probably accumulated in the lee of the oyster banks under variably marine-freshwater conditions, while the supralittoral lagoon shores were fringed by algal marshes (Lithofacies 3). The palynology of Lithofacies 3 shows that some marshes accumulated close to the lagoon (dominated by marine dinocysts), while others formed further inland (dominated by terrestrial pollen and spores). In the N of the Sea of the Hebrides Basin, small deltas continued to prograde into the lagoons (Lithofacies 4), and toward the end of Duntulm Formation times, muds and sands colonised by freshwater molluscs (Unio and Neomiodon), the planktonic alga Botryococcus, and dominated by terrestrial pollen and spores (Lithofacies 5), accumulated in this area, representing a basin-wide change from marine to freshwater conditions. The structural high which divided the basins exerted a strong control on lithofacies evolution, effectively preventing any material coarser than silt grade entering the Inner Hebrides Basin. Thickness variation in the Formation is similarly structurally/facies linked, with thick sequences accumulating where sandstones (Lithofacies 4) predominate, and thin sequences occurring close to the structural high.

Plant miospore assemblages obtained from eight beds of the Foulden sequence, ranging from Bed 1 to Bed 17, are basically similar to each other in stratigraphical significance. The presence of Convolutispora circumvallata, Crassispora trychera and Schopfltes claviger and the absence of Lycospora pusilla suggest assignment to the Schopfites claviger-Auroraspora macra (CM) Biozone. This indicates the Courceyan Stage of the British Dinantian and the late Tournaisian (Tn3) of the Belgian Series. Comparable miospore assemblages have been described from Cementstone Group localities elsewhere in Berwickshire, East Lothian, Ayrshire and northern England. Preservation, and lack of marine palynomorphs and scolecodonts, suggest non-marine deposition. The presence of vitrinite fragments and megaspores as well as miospore tetrads suggests little transport before deposition.