MIOCENE PALYNOFLORA FROM THE GUATUPÊ OUTCROP, CURITIBA BASIN, PARANÁ, SOUTHERN BRAZIL

Abstract

For the first time in the Curitiba Basin, a palynological assemblage is registered that allows a reliable dating. The material studied comes from the Guatupê outcrop, located in the eastern Curitiba Basin, in the São José dos Pinhais city. The outcrop, at first, is considered to belong the Guabirotuba Formation. Of the 55 samples collected, only three, from the lower part of the outcrop consisting of very poorly selected sand, with pebbles and varying levels of organic matter, showed positive results. Among about 80 palynotaxa identified, the occurrence of Cyatheacidites annulatus (spore) and Psilaperiporites minimus (pollen), together with the absence of Ciacatricosisporites dorogensis (spore), ensures that the Miocene is the maximum age. Miocene age is also suggested by the presence of “Microthyriaceous germlings”. On the other hand, the possibility of dealing with the Quaternary was ruled out, as the pollen grains of Araucaria and Poaceae — abundant elements in the Quaternary of southern Brazil — are scarce. The presence of microalgal elements (e.g., Ovoidites, Pseudoschizaea, Spintetrapidites and Tetraporina) attests to the lacustrine depositional environment. The abundance of fern and fungal spores, combined with the extreme scarcity of disaccate pollen grains (e.g., Podocarpidites and Dacrydiumites), suggests a humid and hot climate.