Miocene carpological floras of the Konin region (Central Poland)

摘要

Carbonaceous, three-dimensionally preserved macroscopic plant remains from the Lubstów, Gos?awice and P?tnów brown coal open-pit mines are described and illustrated, providing a comprehensive elaboration of the middle Miocene carpological floras of the Konin region. The diaspores represent the following families: Pinaceae, Sciadopityaceae, Cupressaceae, Annonaceae, Cabombaceae, Nymphaeaceae, Araceae, Typhaceae, Cyperaceae, Vitaceae, Rosaceae, Rhamnaceae, Fagaceae, Myricaceae, Cornaceae, Nyssaceae, Symplocaceae, Ericaceae, Araliaceae, and Adoxaceae. Forty-two species were recognised or documented for the first time in the Konin region. Two genera, three species and three morphotypes are described as new taxa. Most of these plant remains represent azonal vegetation. Ericaceous bogs, pine bogs and mixed coniferous bogs, accompanied by Gyptostrobus swamp forests and various aquatic plant communities, are suggested as the most widespread vegetation types. Remains representing mesophytic, zonal vegetation, resembling extant evergreen broad-leaved and mixed mesophytic forests, are sparse. A Sciadopitys raised bog, a mixed coniferous bog subtype, was one of the important biomass sources forming the brown coal of the I-Middle Polish seam group. Other bog types recognised in Lubstów presumably also played a part in this process. Wildfire is suggested as an important factor controlling the Miocene vegetation of the Konin region. The floristic composition and lithostratigraphy indicate the Badenian age (16.3–12.8 Ma) for the studied floras, but radiometric data suggest that two Lubstów floras are older and one is younger than 13.6 Ma. Biostrati-graphically, Lubstów floras were correlated with the Klettwitz – Salzhausen floristic complex. Based on several climatic indicators and biostratigraphic correlation, the climate is estimated to have been humid, warm-temperate or subtropical. The upper Miocene lower Rhenish Basin floras are the most comparable in floristic and plant communities’ composition. Tropical – subtropical, Mediterranean and extinct genera represent approximately 40% of the genera identified in Lubstów.