Control of inherited structural fabric on the development and exhumation of passive margins : insights from the Araçuaí Orogen (Brazil)

The Aracuai Orogen, in eastern Brazil, was formed during the Neoproterozoic - Cambrian amalgamation of West Gondwana. During the Mesozoic - Cenozoic opening of the South Atlantic Ocean , the asso-ciated divergent tectonics, the orogen developed as basement to the passive margin of South America , wa...

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Bibliographic Details
Published in:Geoscience Frontiers
Main Authors: Liberal Fonseca, Ana Carolina, Novo, Tiago, Fonte-Boa, Tobias, Kuchenbecker, Matheus, Fragoso, Daniel Galvão Carnier, Peifer, Daniel, Pedrosa-Soares, Antônio Carlos, De Grave, Johan
Format: Article in Journal/Newspaper
Language:English
Published: 2023
Subjects:
Earth and Environmental Sciences
General Earth and Planetary Sciences
Thermal history
Denudation
Tectonic inheritance
Reactivations
South Atlantic
Hydrocarbons
SAO-FRANCISCO CRATON
NEOPROTEROZOIC MACAUBAS GROUP
TERM LANDSCAPE EVOLUTION
WEST-CONGO OROGEN
RIO-DE-JANEIRO
CONTINENTAL-MARGIN
DENUDATION HISTORY
SE BRAZIL
STRATIGRAPHIC EVOLUTION
POSTRIFT REACTIVATION
Sion
South Atlantic Ocean
Online Access:https://biblio.ugent.be/publication/01HGAGES6N7R3BFH271NRDYJ61
http://hdl.handle.net/1854/LU-01HGAGES6N7R3BFH271NRDYJ61
https://doi.org/10.1016/j.gsf.2023.101628
https://biblio.ugent.be/publication/01HGAGES6N7R3BFH271NRDYJ61/file/01HGAGHP42PVSYSE2DVGWS5BWV
Description
Summary:The Aracuai Orogen, in eastern Brazil, was formed during the Neoproterozoic - Cambrian amalgamation of West Gondwana. During the Mesozoic - Cenozoic opening of the South Atlantic Ocean , the asso-ciated divergent tectonics, the orogen developed as basement to the passive margin of South America , was progressively covered by thick offshore sedimentary basins, particularly the Espirito Santo, Mucuri, and Cumuruxatiba basins, in which hydrocarbon systems have been exploited. Our understanding of the Aracuai Orogen'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 Aracuai Orogen resolve three discrete basement cooling and associated erosional exhumation episodes. In the Pre-Rift phase, Jurassic - Hauterivian ero-sion of the Aracuai Orogen is most likely related to the adjoining intra-continental West Gondwana flex-ural 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 Aracuai Orogen experi-enced slower denudation rates in areas closer to the Sao Francisco Craton, which suggests that the tec-tonic 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 ...

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