A pliocene flora from the subachoque valley (Cordillera Oriental, Colombia)

A palynological and macrobotanical study was made of a 40 cm long peaty clay layer (SUBA 39 section) intercalated in fluvial deposits of Pliocene age from the Subachoque Valley, located at the northwestern border of the high plain of Bogota in the Cordillera Oriental of Colombia at an elevation of 2820 m above sea level. This has permitted a detailed reconstruction of the former regional and local vegetation cover. The regional one consisted of an admixture of lower tropical, subandean and Andean forest elements that most probably developed in a tropical lowland environment. Few local vegetation elements have been found; only ferns were abundant along the shores of the former closed river branch. This reconstruction represents one of the vegetation types that existed at the beginning of the final upheaval of the northern Andes. All macrofossil types (cuticular remains, fruits, seeds, etc.) and some newly recognized microfossil types (pollen, fungal spores, etc.) found in the SUBA 39 section, are briefly described and illustrated.