Jadwiga Ziaja

European Jurassic floras: statistics and palaeoenvironmental proxies

Abstract The Jurassic floras of Europe show considerable diversity. To examine the extent of this diversity and its possible causes we used multivariate statistical methods (cluster analysis, PCA, NMDS) to compare all significant Jurassic floras in Europe. Data were based on 770 taxa from 46 fossiliferous occurrences (25 units) from France, Germany, Greenland, Hungary, Italy, Norway, Poland, Romania, Scotland, Serbia, Sweden, Switzerland, and the United Kingdom. Statistical analyses were applied at species level and genus level, and also performed for the major plant groups. The genus cladograms show affinities between different localities based on environmental factors, while the cladograms based on species affinities indicate only taxonomical correlations. The study shows that locality age does not seem to be of paramount importance for floral composition.

A palaeoenvironmental reconstruction based on palynological analyses of Upper Triassic and Lower Jurassic sediments from the Holy Cross Mountains region

ABSTRACT The material for this study was taken from various sites in the Holy Cross Mountains: Studzianna, Huta OP-1 and Przysucha P-3 (bore cores), and Odrowąż (geological outcrop). Palynological and palynofacial analyses were used to reconstruct the Upper Triassic and Lower Jurassic vegetation and palaeoenvironment of that area. Samples from all the sites are characterised by having majority of terrestrial particles. The slides were dominated by translucent phytoclasts and small opaque phytoclasts. Pollen grains and spores were also present. The presence of marine palynomorphs was not confirmed in the samples from any of the sites, dinoflagellate cysts did not occur, and there were no foraminiferal test linings. The Sporomorph EcoGroup (SEG) model (Abbink 1998) was applied to characterise the ecological types of the plant assemblages. The most frequently occurring sporomorphs were assigned to Upland, Lowland and River SEGs. Stratigraphical changes in each of the SEGs indicate differences in climatic conditions. The floristic composition of the Studzianna, Huta and Odrowąż localities inferred from sporomorphs differs somewhat from the composition reconstructed from macroremains.