Palinomorfos ante-cenomanianos do «Grés do Buçaco» (Lousã, Portugal)

Abstract

Key-words: Palynology - Lower Cretaceous - Lousã Basin - Portugal. The palynological study of sediments from lower leveis of Lousã basin (Lomba do Alveite Arkoses). is presented. The palynological association ineludes several species of Appendicisporites and Cicatricosisporites, Costatoperforosporites sp., lschyosporites teixeirae, Pattelasporites tavaredensis, Echinatisporis sp., Spheripollenites perinatus, Tricolpopollenites sp. and Retitricolpites maximus. The presence of the last two forms, and the absence of Normapolles, suggest an ante-Cenomanian, most probably Albian age for the assemblage. From these results, the begining of the infiUing of the Lousã basin, is, at least in part, synchronous with the deposition of the «Grés Grosseiro Inferior» from the Occidental portuguese Basin. The presence of Lower Cretaceous sediments directiy overiying the Paleozoic basement, hence outside of the Occidental Portuguese Basin, is shown for the first time.