Palynological and sedimentary analysis of the Igarape Ipiranga and Querru 1 outcrops of the Itapecuru Formation (Lower Cretaceous, Parnaiba Basin), Brazil

The siliciclastic sediments of the Itapecuru Formation occur in a large area of the Parnaiba Basin and its deposits crop out along the Itapecuru River, in Maranhao State, northern Brazil. The palynological analysis of the Igarape Ipiranga and Querru 1 outcrops strata yields a rich and diversified data. The presence of index-palynofloras in assemblages allows the identification of the Complicatisaccus cearensis Zone, of Late Aptian-Early Albian age. Terrestrial palynomorphs are abundant in the assemblages, being represented by bryophytes and pteridophytes, especially perisporate trilete spores (Crybelosporites and Perotrilites), and gymnosperms and angiosperms (Afropollis and Elaterosporites). The composition of palynological assemblages suggests the presence of moist soils for both outcrops. Acritarchs were recovered in the Querru 1 outcrop, which suggest a marine setting supporting a tidal flat environment indicated by facies associations. Furthermore, reworked Paleozoic palynomorphs were observed in the Querru 1 outcrop. The microflora from Igarape Ipiranga outcrop suggests terrestrial environment corroborating with floodplain environment indicated by facies association. (C) 2015 Elsevier Ltd. All rights reserved.