Late Pennsylvanian (Stephanian C) limnic wetlands from the Surroca-Ogassa coalfield, (eastern Pyrenees, Catalonia, Spain) are characterised for the first time based on combined sedimentological, taphonomic, and palaeoecological analysis. Peat mires occurred in floodplain settings, and they were probably formed by monospecific stands of Sigillaria. These mires were swept away by pyroclastic flows, which produced the accumulation and orientation of sigillarian logs on the top of the volcanoclastic deposits. Floodplains were generally devoid of vegetation, with the exception of small sphenopsid stands. Calamites also grew within active fluvial channels. They were accompanied by marattialean tree ferns in low-regime fluvial channels. Medullosan pteridosperms bearing Alethopteris foliage and Pachytesta seeds were extremely abundant in particular horizons and grew probably in floodplain margins covering ancient peat mires. Parautochthonous cordaitalean remains were abundant in distal alluvial deposits.
Late Pennsylvanian, Pyrenees, coal Swamps, palaeobotany, Spain