PLANT LIFE DURING THE CARBONIFEROUS-PERMIAN TRANSITION ON THE NORTH-CHINA MICRO-CONTINENT

The North China Block was a micro-continent in tropical latitudes surrounded by oceans. On this block terrestrial strata from the time of the Carboniferous-Permian transition (C-P) are preserved in a number of basins some of which are also coal-mining areas. Marine beds are absent in most places. Plant fossils are plentiful in the terrestrial deposits and have been studied to clarify the stratigraphy and aid the coal industry. The fossil flora of this interval belongs to the Cathaysian Floral Realm. The flora consists of numerous taxa also known from the Euramerican Floral Realm but also includes a significant number of endemic elements that justify the separation as a different floral realm. Traditionally, the Carboniferous-Permian (C-P) boundary was placed in the middle of the Taiyuan Formation while our own investigations in the Wuda Coal Field in Inner Mongolia have shown that the newly defined C-P boundary at 299 Ma coincides at least in that field with the boundary of the Taiyuan Formation with the overlying Shanxi Formation. This means that a number of floras that were formerly described as lower Permian are in reality late Carboniferous in age. A volcanic tuff dated as at or near the C-P boundary contains an in situ flora that grew on peat and demonstrates the patchiness of the vegetation in the landscape.