Dating aeolian sediments from Cabo Frio, Rio de Janeiro, using Ti-Li center electron spin resonance, thermoluminescence and optically stimulated luminescence

• Autor(a) principal: CARMO, LUCAS S. do
• Data de Publicação: 2020
• Outros Autores: WATANABE, SHIGUEO, DEWITT, REGINA, SILVA, RAFAELA J., FELIPE, LUIZ, CHUBACI, JOS?? F.D., INTERNATIONAL NUCLEAR ATLANTIC CONFERENCE
• Tipo de documento: Artigo de conferência
• Título da fonte: Repositório Institucional do IPEN
• Texto Completo: http://repositorio.ipen.br/handle/123456789/30652
• topic: isotope dating; sediments; gamma spectroscopy; gamma spectra; titanium; lithium; lithium titanates; sedimentary rocks; sand; geomorphology; coastal regions; brazil

In this work, optically stimulated luminescence (OSL), thermoluminescence (TL) and electron spin resonance (ESR) were used to date coastal aeolian sediments from a dunefield known as Dama Branca (White Lady) in Rio de Janeiro, Brazil. Sediments have been collected from seven different points to study sand transportation and stabilization. Results obtained by those different techniques were compared. The equivalent dose (De) measured by OSL, was obtained using the Single Aliquot Regenerative protocol (SAR), TL results have been corrected measuring residual TL and ESR measurements were carried out using Ti-Li center. The thermal stability of Ti-Li center was evaluated, samples were preheated to exclude the Ti-Li center thermally sensitive component. The gamma-ray spectroscopy was used to measure Uranium, Thorium and Potassium concentrations in the soil, the values were analyzed with the Dose Rate and Age Calculator (DRAC) to generate the Annual Dose Rate (Dr). A morphological analysis showed that the dunefield has been moving influenced by semi-arid conditions and upwelling close to the coast. Ages from 0.05 to 2.22 thousand of years were found.