The palynology of the Lower Permian (Asselian–?Artinskian) Copacabana Formation of Apillapampa, Cochabamba, Bolivia

Abstract

The palynostratigraphy of the lower and Coal members of the Copacabana Formation from Apillapampa, central Bolivia was investigated. Twelve samples yielded abundant and diverse, moderately well-preserved pollen and spores. One new spore species, Dictyotriletes cousmineri, is described and 52 species are recorded for the first time in Bolivia. Two species each of acritarchs and scolecodonts are also present. The lowermost assemblage yielded Vittatina and taxa such as Pakhapites ovatus and Marsupipollenites striatus, which are characteristic of the Asselian–Early Artinskian Vittatina costabilis Zone of the Paraná Basin, Brazil. The uppermost assemblage is defined by the appearance of several species of Lueckisporites, together with species of Vittatina, Lunatisporites, Pakhapites, Hamiapollenites, Corisaccites, Mabuitasaccites, Striomonosaccites, Striatoabieites, Striatopodocarpites and Weylandites. Abundant monolete and trilete spores with subordinate pollen grains are present in the Coal Member. Those species suggest correlation to the Middle Artinskian–Wuachiapingian Lueckisporites virkkiae Zone of the Paraná Basin. Highly variable associations of gymnosperms occur in the lower member whereas pteridophytes, sphenophylls and lycopods are dominant in the overlying Coal Member. These groups of plants characterised terrestrial landscapes along marine margins during the Early Cisuralian, and confirm the widespread distribution of the Glossopteris flora during the Permian in Gondwanaland. Preliminary radiometric data from interbedded tuffs suggest an Asselian–Sakmarian age for the marine Copacabana Formation and a Sakmarian–?Artinskian age for the overlying Coal Member. These new data are highly significant in terms of Permian correlations in central South America.

Keywords:

• biostratigraphy
• Bolivia
• Copacabana Formation
• Early Permian
• palaeoecology
• palynology
• taxonomy

Acknowledgements

This contribution is one of a series on the Upper Palaeozoic lithostratigraphical units of Bolivia. The authors acknowledge the invaluable help of Paulo A. Souza (UFRGS), Gustavo Holfeltz (FCEN, UBA) and Renee Breedlovestout (University of Idaho) for processing most of the samples. We also thank Shirely Lopez and Sergeotecmin for help with logistics, Shirley and Nestor Jimenez for hospitality in La Paz and Ramiro Suárez-Soruco and Ricardo Céspedes for assistance at the Museum of Palaeontology, Cochabamba. Oscar Arispe accompanied us to Apillapampa and other sites in 1997 and 2007. We also thank the Arispe-Pérez family in La Paz. Fieldwork in 2007 and 2008 was concurrent with Peter Isaacson and Heidi Anderson’s work in the southeasten Subandes. Work at Apillapampa and at Zudañez included Roberto Iannuzzi, Enrique Díaz-Martínez and Renee Breedlovestrout. Charles Henderson and Vladimir Davydov provided important contributions and collected samples at Apillapampa during a small flash flood in March 2007. This work is dedicated to the people of Bolivia. We acknowledge funding from Projects CGL2006-07376/BTE (2007–2009, granted to Enrique Díaz-Martínez) provided by the Instituto Geológico y Minero de España and PIP 5518 CONICET (2005–2007, granted to Mercedes di Pasquo) by the Consejo Nacional de Investigaciones Científicas y Técnicas. Moreover, Fulbright and CONICET gave Mercedes di Pasquo a research scholarship grant in 2009 to work in collaboration with Peter Isaacson and Heidi Anderson (University of Idaho), who are all excellent colleagues and friends. This study was also supported by funds from the University of Buenos Aires (UBACYT X 428, 2008-2010, granted to Mercedes di Pasquo) and we are grateful to FCEN, UI and CICYTTP, where the main part of this work was carried out.