Ecocentrismo e sua Aplicabilidade em Estudos da Geodiversidade

Abstract

The samples used for the study of calcareous nannofossils were provided by the Deep Sea Drilling Project (DSDP) and are referred to the Site 354, Leg 39. The well is located on the Northwestern of the Ceará Rise, in a topographic feature one hundred and fifty meters from the Amazon Fan (Equatorial Atlantic). According to the stratigraphic distribu- tion of nannofossil species, the biostratigraphy of the investigated section was refined and intervals were identified. The main calcareous nannofossils species described and recorded were Isthmolithus recurvus, Sphenolithus pseudoradians, Sphenolithus ciperoensis, Discoaster barbadiensis, Discoaster saipanensis, Sphenolithus intercalaris, Clausicoccus subdistichus, Sphenolithus distentus, Sphenolithus predistentus, Cyclicargolithus abisectus, Helicosphaera recta, Dis- coaster tanii, Coccolithus pelagicus, Helicosphaera euphratis, Triquetrorhabdulus milowii, among others. The most representative taxa were photomicrographed and measured in order to illustrate the study and construct a biozonation for this range. Through the behaviour of the nannofossil assemblages, paleoclimatic inferences were suggested. Six biozones were described in the Eocene/Oligocene interval.