Control of inherited structural fabric on the development and exhumation of passive margins-Insights from the AraçuaíOrogen(Brazil)  

作　　者：Ana Fonseca Tiago Novo Tobias Fonte-Boa Matheus Kuchenbecker Daniel Galvão Carnier Fragoso Daniel Peifer Antônio Carlos Pedrosa-Soares Johan De Grave 

机构地区：[1]Laboratory for Mineralogy and Petrology,Department of Geology,Ghent University,Krijgslaan 281 S8,9000 Ghent,Belgium [2]Universidade Federal de Minas Gerais,Programa de Pós-Graduação em Geologia,CPMTC-IGC,Campus Pampulha,Belo Horizonte,MG,Brazil [3]Centro de Pesquisas Professor Manoel Teixeira da Costa,Instituto de Geociências,Universidade Federal de Minas Gerais,Belo Horizonte,Brazil [4]Universidade Federal dos Vales do Jequitinhonha e Mucuri,Instituto de Ciência e Tecnologia,Centro de Estudos em Geociências,Laboratório de Estudos Tectônicos,Diamantina,Brazil [5]Petrobras,Rio de Janeiro,RJ,Brazil [6]Instituto de Geociências,Universidade Federal do Rio Grande do Sul,Porto Alegre,RS,Brazil [7]Department of Geosciences,University of Tübingen,Schnarrenbergstr.94-96,72076 Tübingen,Germany

出　　处：《Geoscience Frontiers》2023年第6期30-48,共19页地学前缘（英文版）

摘　　要：The AraçuaíOrogen,in eastern Brazil,was formed during the Neoproterozoic–Cambrian amalgamation of West Gondwana.During the Mesozoic–Cenozoic opening of the South Atlantic Ocean,and the associated divergent tectonics,the orogen developed as basement to the passive margin of South America and was progressively covered by thick offshore sedimentary basins,particularly the Espírito Santo,Mucuri,and Cumuruxatiba basins,in which hydrocarbon systems have been exploited.Our understanding of the AraçuaíOrogen’s passive margin evolution,erosion,and sediment transfer to these basins ultimately depends on constraining the onshore exhumation in response to Mesozoic–Cenozoic events.Here,new and previously published data from apatite fission-track(AFT)analyses and inverse thermal history modelling of(Pre)Cambrian basement rocks from the AraçuaíOrogen resolve three discrete basement cooling and associated erosional exhumation episodes.In the Pre-Rift phase,Jurassic–Hauterivian erosion of the AraçuaíOrogen is most likely related to the adjoining intra-continental West Gondwana flexural subsidence,which increased hillslope and river erosion power.In the Rift and Transitional phases,Barremian–Albian accelerated phase of erosion is associated with the uplift of the Atlantic rift shoulders and the establishment of an oceanic base-level.In the Drift phase,reactivations in response to far-field stresses likely triggered a Late Cretaceous–Paleocene rapid erosion event.The rates at which these events unfolded vary spatially and are controlled by inherited structures.The AraçuaíOrogen experienced slower denudation rates in areas closer to the São Francisco Craton,which suggests that the tectonic reactivation and related surface uplift during the Mesozoic–Cenozoic is in first-order controlled by lithospheric rigidity.Furthermore,the structural framework of the Paramirim and Pirapora aulacogens and NE-oriented shear zones in the orogen’s southeast facilitated later reactivations.From the spatial pattern of denu

关 键 词：Thermal history DENUDATION Tectonic inheritance Reactivations South Atlantic Hydrocarbons 

分 类 号：P588.1[天文地球—岩石学]