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| Passarelli,Cláudia R.; Basei,Miguel A.S.; Siga Jr.,Oswaldo; Sato,Kei; Sproesser,Walter M.; Loios,Vasco A.P.. |
| Since 1964, the Center for Geochronological Research - CPGeo, one of the interdepartmental centers of the Instituto de Geociências (IG) of São Paulo University, has developed studies related to several geological processes associated with different rock types. Thermal Ionization Mass Spectrometry Isotopic Dilution (ID-TIMS) has been the technique widely used in the CPGeo U-Pb Laboratory. It provides reliable and accurate results in age determination of superposed events. However, the open-system behavior such as Pb-loss, the inheritance problem and metamictization processes allow and impel us to a much richer understanding of the power and limitations of U-Pb geochronology and thermochronology. In this article, we present the current methodology used at... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: U-Pb ID-TIMS methodology; U-Pb geochronology of accessory minerals; CPGeo-IGc-USP U-Pb laboratory. |
| Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652009000100010 |
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| Passarelli,Cláudia R.; Basei,Miguel A.S.; Prazeres-Filho,Hélcio J.; Siga-Jr.,Oswaldo; Szabó,Gergely A.J.; Marco-Neto,Joaquim. |
| The Juréia Massif, southeastern São Paulo State (Brazil), is part of the Registro Domain, limited to the north by the Cubatão-Itariri Shear System and to the south by the Serrinha Shear Zone. Mostly composed of migmatitic granitegneiss rocks, represents a Paleoproterozoic terrane (1.9-2.2 Ga) strongly deformed during the Neoproterozoic (750-580 Ma). The present tectonic scenario was established at the end of the Neoproterozoic, as a result of collages associated with the formation of Western Gondwana. The Ponta da Juréia, our study area within the Juréia Massif, is constituted by paragneisses (garnet-muscovite-biotite gneisses). The monazite U-Pb age of 750 Ma is related to a main regional metamorphic event that reached the high amphibolite facies,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Tectonic domain; Shear zone; Gneissic rocks; U-Pb geochronology. |
| Ano: 2007 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652007000300008 |
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