Biostratigraphic Significance of Lower Cisuralian Palynoflora from Apillapampa, Bolivia

Recent stratigraphic and palynological data from marine and transitional rocks of the Copacabana Formation at Apillapampa in central Bolivia refine the age of Cisuralian palynomorphs in South America. Samples interbedded with volcanic ashes yielded palynomorph taxa arranged into two informal palynoassemblages: the lower assemblage Vittatina costabilis (Vc) occurs in one sample at the base of the Copacabana Formation, and the upper Lueckisporites virkkiae (Lv) assemblage is found in overlying marine and coal-bearing transitional intervals. Ages were also independently refined by a modern review of microfossil (conodonts and fusulinids) and five U–Pb radiometric ages (ID–TIMS of zircon-bearing interbedded tuffs), which confirm that the Copacabana Formation at this location is Asselian and Sakmarian in age. Lueckisporites virkkiae and other palynomorphs are key species of palynozones utilized in South American and global Permian biostratigraphic reconstructions. Hence, a thorough global comparison of these palynofloras and correlations is made in this study, considering the first appearances of mainly cosmopolitan diagnostic taxa. Correlations are established with many similar Permian palynofloras, some also constrained by radiometric data, in South America (Brazil, Uruguay, and Argentina) and elsewhere (Africa, Australia, Oman, and Saudi Arabia).