Hiatuses recognition of the gaps in the tertiary section of the Mundaú subbasin, Ceará Basin: a study based on calcareous nanofossils

Abstract

The analysis of the nanofossiliferous content of 20 wells of the Mundaú Subbasin, Ceará Basin, enabed the recognition of 15 biozones for the Paleocene/Early Miocene interval (Ubarana Formation). The biostratigraphic correlation between the wells studied made eight sections possible (four transversal to coast and four parallel). From the study of these sections, it was possible to recognize six hiatuses associated to erosive/non-depositional events occurred, respectively, during the Ear/y Paleocene, Late Paleocene, Latest Paleocene, Middle Eocene, Late Eocene. and Early Oligocene. From the gaps recognized that identified in the Middle-Eocene Epoch has a special importance for the area in which it occurs and for the geochronologic amplitude.