LUCAS SATIRO DO CARMO

LUCAS SATIRO DO CARMO

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OSL-SAR dating of sediments from Brazilian aeolian system
2019 - CARMO, L.S. do; WATANABE, S.; DEWITT, R.
It has been reported that the formation and stabilization of coastal dune fields in Brazil have a dependence on the climatic changes, Relative Sea Level (RSL) variations, etc. In this work, a dune field known as “Dama Branca”, located in the city of Cabo Frio, Rio de Janeiro, has been studied to understand its mobility. Dating by trapped charge dating techniques as Optically Stimulated Luminescence (OSL) using the Single Aliquot Regenerative protocol (SAR), helps us to understand the formation and dynamics of aeolian systems in Brazil. Samples from two positions; DB and 2DB, were collected from different heights and points for dating. The results obtained by OSL-SAR showed that ages decrease as the height from the dune base increases and older samples are found in deeper horizontal positions. The ages from the base of the studied dunes indicated that its stabilization occurred during the recess of the sea level and that erosion caused by the wind action is revealing an old generation of this dune filed.
Dating aeolian sediments from Cabo Frio, Rio de Janeiro, using Ti-Li center electron spin resonance, thermoluminescence and optically stimulated luminescence
2019 - CARMO, LUCAS S. do; WATANABE, SHIGUEO; DEWITT, REGINA; SILVA, RAFAELA J.; FELIPE, LUIZ; CHUBACI, JOSÉ F.D.
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.
Dating sediments from a terrace found in Iguape - Icapara in southeast coast in the state of São Paulo, Brazil
2018 - CORTEZ, BRUNA; CHUBACI, JOSE F.D.; GOMES, MONISE B.; OLIVEIRA, LETICIA M.; SATIRO, LUCAS C.; ROCCA, RENE R.; ARIZACA, EDY E.C.; WATANABE, SHIGUEO
Dating of shells from Pântano da Malhada, Rio de Janeiro
2018 - GOMES, MONISE B.; CORTEZ, BRUNA; OLIVEIRA, LETICIA M. de; CARMO, LUCAS S. do; CHUBACI, JOSE F.D.; ROCCA, RENE R.; WATANABE, SHIGUEO
Dating aeolian sediments using ESR Ti-Li center in quartz, TL and OSL-SAR
2018 - CARMO, L.S. do; WATANABE, S.; SILVA, R.J.; CHUBACI, J.F.D.
OSL-SAR dating of sediments from brazilian aeolian system: Dama Branca, Rio De Janeiro, morphodynamic study
2017 - CARMO, LUCAS S. do; WATANABE, SHIGUEO; DEWITT, REGINA
It has been reported that the formation and stabilization of coastal dune fields in Brazil have a dependence on the climate changes and Relative Sea Level (RSL) variations. A few topics regarding the morphodynamics of coastal aeolian systems in Brazil can be the RSL variations in the Holocene and weather conditions. In this work, a dune field known as “Dama Branca”, located in the town of Cabo Frio, Rio de Janeiro, has been studied to understand its formation and stabilization. Dating by trapped charge dating techniques as Optically Stimulated Luminescence (OSL) using the Single Aliquot Regenerative protocol (SAR), help us to understand the formation and dynamics of aeolian systems in Brazil. Samples from a dune were collected from different heights and points for dating. The results obtained by OSL-SAR showed that ages decrease as the height from the dune base increase and older samples are found in deeper horizontal positions. The ages for the base of the studied dunes indicated that its stabilization occurred during the recess of the sea level.
Dating stalagmite from Caverna do Diabo (Devil´S Cave) by TL and EPR techniques
2016 - WATANABE, SHIGUEO; CANO, NILO F.; RAO, T.K.G.; SILVA-CARRERA, BETZABEL N.; CARMO, LUCAS S.; QUINA, ANTONIO J. A. DE; GENNARI, ROSELI F.; MUNITA, CASIMIRO S.; AYALA-ARENAS, JORGE S.; FERNANDES, BRUNO G.
A cylindrical fragment of stalagmite from Caverna do Diabo, State of São Paulo, Brazil, has been studied and dated by thermoluminescence and electron paramagnetic resonance techniques. The thermoluminescence glow curves of stalagmite samples and subsequently gamma irradiated, have shown rise of three peaks at 135, 180 and 265 °C. From electron paramagnetic resonance spectra of stalagmite was possible to clearly identify three paramagnetic centers in the g = 2.0 region: Centers I, II and III are due to , and , respectively. The additive method was applied to calculate the accumulated dose using thermoluminescence peak at 265 °C and the electron paramagnetic resonance signal at g = 1.9973 of CO- 2 radical. The ages of the different slices of stalagmite were determined from the Dac- values and Dan- value, obtaining an average of 86410 for central slice, 53421 for second slice, 31490 for third slice and 46390 years B.P. for the central region of upper end.