title: Electron Spin Resonance Dating of Toxodon Tooth from Upper Ribeira Valley, São Paulo, Brazil.
abstract: Electron spin resonance (ESR) dating was applied to date a sample of fossil tooth found in Ribeira Valley, São Paulo, Brazil. This region is characterized by abundant fossil records of Pleistocene-Holocene South American megafauna belonging to different faunistic moments related to climate changes during the quaternary. As the number of fossils dated is not too large, the dating of materials from this region will provide important information to better understand the events associated with the presence and extinction of these species. The equivalent dose (De) was determined using single exponential fitting resulting in (24 ± 1)Gy. The Dewas converted to age using ROSY ESR Dating program and the concentration of radioisotopes present in the sample and soil determined through neutron activation analysis. The ages cover the range of 25-34 ka. This information is important to contextualize other findings in the region from different sites and to help obtain better information about the climate changes in this region.
authors.affiliation: Universidade do Sagrado Coração (USC), Bauru, São Paulo, Brazil angelamitie@gmail.com.|Departamento de Física, FFCLRP, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil.|Present Address: Rua Irmã Arminda 10-50, Bauru, SP 17.011-160, Brazil.
authors.forename: Angela
authors.initials: A
authors.lastname: Kinoshita
authors.affiliation: Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Aline Marcele
authors.initials: AM
authors.lastname: Ghilardi
authors.affiliation: Universidade Federal de São Carlos (UFSCar), São Carlos, São Paulo, Brazil.
authors.forename: Marcelo Adorna
authors.initials: MA
authors.lastname: Fernandes
authors.affiliation: Instituto de Pesquisas Energéticas e Nucleares, IPEN-CNEN, São Paulo, Brazil.
authors.forename: Ana Maria G
authors.initials: AM
authors.lastname: Figueiredo
authors.affiliation: Departamento de Física, FFCLRP, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil.
authors.forename: Oswaldo
authors.initials: O
authors.lastname: Baffa
mesh_terms: D000818:Animals; D001681:Biological Assay / Q000379:methods*; D001938:Brazil; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods*; D005580:Fossils; D008322:Mammals; D011829:Radiation Dosage; D055110:Radiometric Dating / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014070:Tooth / Q000737:chemistry* / Q000528:radiation effects*