Nuclear radiation importance on archeological and geological dating - application to sediments dating from Cabo Frio

In this work, a dunefield known as Dama Branca has been dated using the following techniques: Optically Stimulated Luminescence (OSL), Thermoluminescence (TL) and Electronic Spin Resonance (ESR). Sediments have been collected from several points to study the age distribution throughout Dama Branca. These ages are related to events of sediments transportation and stabilization. For Dama Branca specifically, variables related to the weather, as rainfall and wind power are appointed to be responsible for its formation. OSL results were obtained applying the SAR protocol, TL and ESR results were obtained using the Multiple Aliquot Additive Dose protocol (MAAD). With respect to ESR measurements, the Ti-Li center had been chosen for dating, once it can be completely bleached by sun light exposition, which makes it suitable for aeolian sediments dating. The Ti-Li center is strongly dependent upon preheat, its stability has been assessed and a preheat temperature of 180 °C was defined. OSL ages is within 0.05 x 103 and 2.05 x 103 years. TL ages are in agreement with OSL ages for samples from the base, however it suggests that DBM2BASE underwent a quicker burial process. ESR results are satisfactory for two samples, 2DB10 and 2DB11 (they follow OSL and TL results). The ages were compared to a morphological study, and in recent works about the weather in the Cabo Frio region, it has been seen that the studied areas were formed under the influence of arid conditions and cold water, variables that controls the sediment transportation in the region. (AU)