PALINOLOGIA DE DEPÓSITOS RUDÁCEOS DA REGIÃO DE ITATIAIA, BACIA DE RESENDE – RJ

Abstract

The Resende Basin is associated with rifting processes which characterize the Cenozoic geologic evolutionof southeastern Brazil. Some palynological information is available from alluvial plain deposits of itssedimentary fill, the Resende Formation. Other associated deposits, having questionable relationships withthis unit, have also been mentioned in the literature. One of these consists of rudaceous deposits of alluvialfans, in which the clasts are chiefly of alkaline rocks from the Itatiaia massif. These deposits, of controversedage, include silty-sand layers, very rich in organic matter, whose palynological potential motivated the researchreported here.The palynological association suggests an Oligocene age for the deposition of the organic matter. Froma paleoecological point of view, this deposition took place under stagnant conditions, in a tropical to subtropicalclimate.Geologically, these results reinforce the idea of a close genetic relationship between the rudaceousalluvial fan deposits and the alluvial plain sediments of the Resende Formation. It is proposed here the nameof Itatiaia Formation for the alluvial fan deposits.