In the present work, luminescence dating of sedimentary deposits, from the coast of the State of Maranh^o, in northeast Brazil, was done. Samples were collected from the Post-Barreiras sediments, a quartzose sandy uni...In the present work, luminescence dating of sedimentary deposits, from the coast of the State of Maranh^o, in northeast Brazil, was done. Samples were collected from the Post-Barreiras sediments, a quartzose sandy unit that is extensive along the entire northeast and northern Brazilian coast, where they occur overlying early to middle Miocene Barreiras Formation. A great part of the Post-Barreiras sediments is massive, which precludes its depositional setting interpretation. However, this unit consists of three successions, the lowermost one including highly bioturbated deposits suggestive of marine influence, and the two uppermost ones displaying dune dissipative structures related to eolian processes along coastal areas. The study aimed to compare MAR （multiple aliquot regeneration） and SAR （single aliquot regeneration） protocols for dating these deposits. Discussion involving origins of depositions will also include single aliquot measurements. The ages obtained by OSL （optical stimulated luminescence）-SAR protocol range from （0.5 ± 0.1） ka to （84 ± 6） ka.展开更多
文摘In the present work, luminescence dating of sedimentary deposits, from the coast of the State of Maranh^o, in northeast Brazil, was done. Samples were collected from the Post-Barreiras sediments, a quartzose sandy unit that is extensive along the entire northeast and northern Brazilian coast, where they occur overlying early to middle Miocene Barreiras Formation. A great part of the Post-Barreiras sediments is massive, which precludes its depositional setting interpretation. However, this unit consists of three successions, the lowermost one including highly bioturbated deposits suggestive of marine influence, and the two uppermost ones displaying dune dissipative structures related to eolian processes along coastal areas. The study aimed to compare MAR （multiple aliquot regeneration） and SAR （single aliquot regeneration） protocols for dating these deposits. Discussion involving origins of depositions will also include single aliquot measurements. The ages obtained by OSL （optical stimulated luminescence）-SAR protocol range from （0.5 ± 0.1） ka to （84 ± 6） ka.
