Palynology of the Iscayachi Formation (Cambro-Ordovician) from the Cordillera Oriental of Southern Bolivia: New data from the western margin of Gondwana.

VERGEL, M. DEL M., ARÁOZ, L. AND ACEÑOLAZA, G.F.

GEOLOGICA ACTA

UNIV BARCELONA

Lugar: Barcelona; Año: 2013 vol. 11 p. 167 - 176

1695-6133

.The first late-Cambrian aged palynomorph assemblage of Bolivia is presented. The sampled material comes fromthe Cambro-Ordovician Iscayachi Formation cropping out in the Antenna of the Sierra de Sama, Tarija department,southern Bolivia. The palynomorph assemblage occurs in levels correlated to the Parabolina (Neoparabolina)frequens argentina trilobite biozone. It is comprised of Acanthodiacrodium spp., Cristallinium cambriense, Cymatiogaleacf. C. aspergillum, C. velifera, C. virgulta, Dasydiacrodium spp., Eliasum llaniscum, Impluviculusmultiangularis, Ladogella rommelaerei, Ladogella sp., Leiofusa sp., Leiosphaeridia sp., Lophosphaeridium sp.,Lusatia? sp., Micrhystridium sp., Poikilofusa squama, Poikilofusa sp., Polygonium dentatum, Retisphaeridiumbrayense, Saharidia fragilis, Solisphaeridium akrochordum, S. lucidum, Timofeevia phosphoritica, Timofeeviamicroretis, Vulcanisphaera africana and V. turbata. The assemblage provides elements of comparison with previouslyreported palynofloras in northern Argentina, eastern Newfoundland, southwestern Sardinia, Algeria, northernSpain, Baltica and Avalonia (Arctic Russia, East-European Platform). All microphytoplancton are indicativeof cold water affinities as expected from the western margin of Gondwana, showing some Baltic affinities as well.