Navegando por Palavras-chave "OSL dating"

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    Age of depositional and weathering events in Central Amazonia
    (Pergamon-Elsevier Science Ltd, 2017) Sant'Anna, Lucy Gomes; Soares, Emilio Alberto do Amaral; Riccomini, Claudio; Tatumi, Sonia Hatsue [UNIFESP]; Yee, Márcio [UNIFESP]
    In the last three decades, several studies have been devoted to understanding the role of Late Pleistocene Holocene climate changes in the Amazonia lowlands environment. However, most of these studies used data obtained from sedimentary deposits (lakes, swamps, and colluvium) located away from the central plain or on the edges of the Amazonia region. This article integrates optically stimulated luminescence and accelerated mass spectrometry C-14 ages with sedimentological and geomorphological data obtained during this study or compiled from the literature for fluvial and lacustrine deposits of the central alluvial plain of the Solimoes-Amazon River. The age data allow us to present a chronological framework for the Late Pleistocene Holocene deposits and conclude that (i) the dryness of the LGM in central Amazonia lowlands is recorded by the formation of fluvial terraces and their weathering to pedogenic hematite between 25.3 ka and 17.7 ka
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    Dating human occupation at Toca do Serrote das Moendas, Sao Raimundo Nonato, Piaui-Brasil by electron spin resonance and optically stimulated luminescence
    (Elsevier B.V., 2014-12-01) Kinoshita, Angela; Skinner, Anne R.; Guidon, Niede; Ignacio, Elaine; Felice, Gisele Daltrini; Buco, Cristiane de Andrade; Tatumi, Sonia Hatsue [UNIFESP]; Yee, Márcio [UNIFESP]; Figueiredo, Ana Maria Graciano; Baffa, Oswaldo; Universidade de São Paulo (USP); Univ Sagrado Coracao; Williams Coll; FUMDHAM Fundacao Museu Homem Amer; EHESS; UNIVASF Univ Vale Sao Francisco; UFPi Univ Fed Piaui; Universidade Federal de São Paulo (UNIFESP); IPEN
    Excavation of Toca do Serrote das Moendas, in Piaui state, Brazil revealed a great quantity of fossil wild fauna associated with human remains. in particular, fossils of a cervid (Blastocerus dichotomus) were found, an animal frequently pictured in ancient rock wall paintings. in a well-defined stratum, two loose teeth of this species were found in close proximity to human bones. the teeth were independently dated by electron spin resonance (ESR) in two laboratories. the ages obtained for the teeth were 29 +/- 3 ka (thousands of years) and 24 +/- 1 ka. the concretion layer capping this stratum was dated by optically stimulated luminescence (OSL) of the quartz grains to 21 +/- 3 ka. As these values were derived independently in three different laboratories, using different methods and equipment, these results are compelling evidence of early habitation in this area. (C) 2014 Elsevier B.V. All rights reserved.