CARACTERIZAçãoPALEoAMBIEnTALuTILIZAnDoARGILAS CoSTEIRASDESuBSuPERFíCIE-ESTuDoDECASo:BAíADE SEPETIBA-RJ

This work was realized in the coastal plain of Itaguai city, Rio de Janeiro state, aiming to analyze the subsurface clay collected from sandy ridges with the aim of characterizin g the paleoenvironmental evolution of this area. For that purpose, we drilled several boreholes followed by particle size and mineralogical X-ray diffraction analysis. In the analysed samples, kaolinite, illite, smectite and traces of goethite were identified in descending order of abundance. This mineralogical association is typical for warm intertropical, lacustrine and/or river environment. Consequently, we can purpose a fluvial-deltaic paleoenvironment for this area including the presence of an ancient restricted intradune lake.