Variações do nível relativo do mar nos últimos 7.000 anos A.P. na planície costeira de Jacarepaguá - Rio de Janeiro: aplicação do programa CALIB 5.0.1

Abstract

The Jacarepaguá coastal plain, sector Barra da Tijuca/ Recreio dos Bandeirantes, Rio de Janeiro is characterized by extensive shorelines, with 18,5km of extension, for beaches and for a system of lagoons isolated from littoral by beach barriers produced of the relative oscillations of the sea-level in the last 7.000 years B.P. The fast process of urbanization succeeded in the decade of 1970 modified the natural environments of this coastal plain. This master dissertation has as objective a study about the relative oscillations of the sea-level in the last 7.000 years B.P., in the coastal plain of Jacarepaguá, using as referential the calibration of the fifteen dating for 14C gotten in the area. The calibration program - CALIB 5.0.1 was used in conversion of the conventional ages for 14C for a calibrated calendar. It was used the standard deviation one sigma ranges, with 68,3% probability and two sigma ranges, with 95,3% probability supplying the reliable interval for the each conventional age. The values gotten in the calibration associates to the information on the evolution process and characterization of main environments of the plain resulted in the construction of relative sea-level curve, with old marine positions corresponding the calibrated ages between 6.357 and 2.912 years B.P. During this interval, the amplitude of the sea-level was between 4.0 m, 3.0 m and 2.0 m above of the current one. The result of the paleosea-level reconstruction in the region is consistent with the studies carried in previous works in the other sectors of the Brazilian coast.