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Rhyacian to Orosirian short-lived polyphase deformation and migmatization in northernmost São Francisco Craton, Brazil
Precambrian Research ( IF 3.2 ) Pub Date : 2023-12-12 , DOI: 10.1016/j.precamres.2023.107252
Simone Cerqueira Pereira Cruz , Érica Neres dos Santos , Vanderlúcia dos Anjos Cruz , Carlson Matos Maia Leite , Elson Paiva Oliveira , Michel Macedo Meira , Joseneusa Brilhante Rodrigues , Basílio Elesbão da Cruz Filho

The Minas-Bahia Orogen, which is Siderian-Orosirian age, is exposed in the northern sector of the São Francisco Craton and in its African counterpart, the Congo Craton. In this sector, two orogenic domains outcrops with geological evolution and terrains with different trends: Western and Eastern Bahia. The advance of scientific knowledge in the northeast of the West Bahia Orogenic Domain has revealed the existence of more tectonic terrains than those traditionally delimited, and reveal the presence of juvenile terranes and cratonic crust separated complex zones where they interacted. The region of interaction between the Gavião and Bom Jesus da Lapa Paleoplate has been the subject of debates about the tectonic significance of granulitic rocks with Meso-Neoarchean protoliths, which are intruded by Rhyacian - Orosirian granitoids. The set of geological data presented in this article demonstrates that the metatexite migmatites with felsic granulitic paleosome and charnockitic neosome were generated during the initial phases of the collision between these two paleoplates, between 2068 and 2058 Ma. The structural mass transport is from NW to SE. The youngest migmatization event, in high amphibolite facies, occurred during NNW-SSE trending sinistral strike-slip tectonics as suggested by the emplacement of Dn+3 neosomes controlled by S/C/C' structures, in between 2049–2000 Ma. The interpreted tectonic model is complex and involves the accretion and collision among Bom Jesus da Lapa, Gavião and Jequié paleoplates during the Rhyacian-Orosirian, contributing to the advancement of knowledge of tectonic pieces and their interactions that contributed to the formation of Columbia supercontinent.



中文翻译:

巴西圣弗朗西斯科克拉通最北端的雷亚纪到奥罗西纪的短暂多相变形和混合作用

米纳斯-巴伊亚造山带,即晔德阶-奥罗西阶时代,暴露在圣弗朗西斯科克拉通的北段和非洲对应的刚果克拉通。在该区域,两个造山带露头,其地质演化和地形具有不同的趋势:西巴伊亚和东巴伊亚。西巴伊亚造山域东北部科学知识的进步揭示了比传统界定的构造地形更多的存在,并揭示了新生地体和克拉通地壳的存在,这些地体和克拉通地壳将它们相互作用的复杂区域分开。加维奥古板块和 Bom Jesus da Lapa 古板块之间的相互作用区域一直是有关中-新太古代原岩的麻粒岩的构造意义争论的主题,这些原岩被瑞亚纪 - 奥罗西纪花岗岩类侵入。本文中提供的一组地质数据表明,具有长英质粒岩古体和卡诺岩新体的后变岩混合岩是在这两个古板块碰撞的初始阶段(2068 Ma 至 2058 Ma)生成的。结构质量输送是从西北到东南。最年轻的混合岩化事件发生在高角闪岩相中,发生在 NNW-SSE 走向的左旋走滑构造期间,由 S/C/C' 结构控制的 D n+3新体侵位表明,发生时间为 2049-2000 Ma。解释的构造模型很复杂,涉及瑞亚纪-奥罗西纪期间 Bom Jesus da Lapa、Gavião 和 Jequié 古板块之间的吸积和碰撞,有助于提高对构造碎片及其相互作用的认识,从而促成哥伦比亚超大陆的形成。

更新日期:2023-12-13
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