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The Patos-Pernambuco shear system of NE Brazil: Partitioned intracontinental transcurrent deformation revealed by enhanced aeromagnetic data.

Fossen, Haakon; Harris, Lyal B. ORCID logoORCID: https://orcid.org/0000-0003-1747-1813; Cavalcante, Carolina; Archanjo, Carlos José et Ávila, Carlos F. (2022). The Patos-Pernambuco shear system of NE Brazil: Partitioned intracontinental transcurrent deformation revealed by enhanced aeromagnetic data. Journal of Structural Geology , vol. 158 . p. 104573. DOI: 10.1016/j.jsg.2022.104573.

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Résumé

The Neoproterozoic-Cambrian (Brasiliano) intracontinental Patos-Pernambuco shear system is developed in Archean to Neoproterozoic crust, reactivating rift margins N of the São Francisco Craton. We here use enhanced aeromagnetic images to reveal internal details of the broad E-W dextral Patos and Pernambuco shear zones, the intervening Central (Transversal) Domain and the adjacent Northern Domain. We estimate shear strains up to 50–60 and a total of ca. 350 and 200 km dextral displacement for the Patos and Pernambuco shear zones, respectively. Deflection of foliations, fold axial surfaces and plutons as well as internal S-C fabrics and asymmetric folds within these large shear zones confirm dextral displacement. However, the dominant population of NE-trending shear zones in the Central Domain, by many considered dextral, are here confirmed to be sinistral and thereby elongating this domain. The Northern Domain behaved differently, hence large-scale Ediacaran strain partitioning in the region is suggested, where different blocks experienced different deformation between major simple-shear dominated shear zones. We show how much more structural information can now be obtained from enhanced aeromagnetic data than from field mapping alone; aeromagnetic interpretations, nevertheless, still draw on analysis techniques epitomized by John Ramsay.

Type de document: Article
Mots-clés libres: patos and pernambuco shear zones; transcurrent intracontinental shear; brasiliano orogeny; enhanced aeromagnetics; ductile shear fabric
Centre: Centre Eau Terre Environnement
Date de dépôt: 20 août 2026 13:27
Dernière modification: 20 août 2026 13:27
URI: https://espace.inrs.ca/id/eprint/15347

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