Structural and geochronological constraints on the evolution of the Juréia Massif, Registro Domain, State of São Paulo, Brazil

Anais da Academia Brasileira de Ciências

Cláudia R. Passarelli²  Miguel A.s. Basei²  Hélcio J. Prazeres-filho²  Oswaldo Siga-jr.²  Gergely A.j. Szabó²  Joaquim Marco-neto¹ 

[1] ,Universidade de São Paulo Instituto de Geociências São Paulo SP ,Brasil

关键词: tectonic domain;    shear zone;    gneissic rocks;    U-Pb geochronology;    domínio tectônico;    zonas de cisalhamento;    rochas gnáissicas;    método U-Pb;   

DOI  :  10.1590/S0001-37652007000300008

来源: SciELO

【 摘 要 】

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, recorded in rocks from the Itatins Complex and Cachoeira Sequence as well, which also belongs to the Registro Domain. The paragneissic rocks of this study are affected by the E-W-trending Serrinha Shear Zone, registering a predominantly dextral movement. Biotite K-Ar ages of 482 ± 12 Ma may represent later movements and reflect the younger ages of reactivation of the major lineaments and juxtaposition of the tectonic blocks involved.

【 授权许可】

CC BY   
 All the contents of this journal, except where otherwise noted, is licensed under a Creative Commons Attribution License