Macrofloral and microfloral changes in the Middle Jurassic plant assemblages of the Cianowice 2 borehole (southern Poland)

The flora of the Cianowice 2 borehole (c. 20 km NW Cracow, Poland), dominated by cycadophytes (mainly bennettitaleans) and conifers, shows high taxonomic diversity relative to low number specimens. Twenty species were identified in 96 determinable plant fragments found 27 core samples: Cladophlebis sp. (ferns), Pachypteris rhomboidalis (Ettingshausen) Nathorst Ptilozamites cycadea (Berger) Möller (seed ferns), Anomozamites nilssonii (Phillips) Seward, Nilssoniopteris solitaria Cleal & Rees, Otozamites mimetes Harris, parallelus Phillips, Pterophyllum thomasii cf. aequale (Brongniart) Nathorst, Ptilophyllum okribense forma ratchiana Doludenko Svanidze, pecten sirkennethii Watson Sincock, Cycadolepis (bennettitaleans), Pseudotorellia grojecensis Reymanówna, samylinae Nosova Kiritchkova, (Gymnospermae incertae sedis), Bilsdalea dura Mirovia szaferi Brachyphyllum stemonium Kendall (conifers). floristic composition is supplemented palynological data. taxa connected five depositional successions distinguished along core: one, alluvial fans; two, four five, meandering/anastomosing river systems with fluvial plain deposits; three, lacustrine/backswamp environment developed on plain. fossil assemblage changes setting within same range taxa, seen mainly changed combinations which are most diverse deposits. Some occur a single succession; some present two or three. sporomorph assemblages particular environments differ significantly from co-occurring macroflora: ferns sporadically macroflora each but they strongly dominate assemblage. Our proposed reconstruction palaeoenvironment slight rise descending into valley depositionary basin, gymnosperms slope at base. shared between nearby Middle Jurassic localities Grojec Zabierzów, majority known Jurassic, suggesting that deposits age.