Description and hierarchy of ductile deformation events in the Camalaú region, state of Paraíba, central portion of the Alto Moxotó Terrane, Borborema Province, Brazil
Journal of the Geological Survey of Brazil
Description and hierarchy of ductile deformation events in the Camalaú region, state of Paraíba, central portion of the Alto Moxotó Terrane, Borborema Province, Brazil
Autor Correspondente: Lauro Cézar M. de Lira Santos | [email protected]
Palavras-chave: Ductile deformation in Camalaú, Moxotó Terrane, Borborema Province
Resumos Cadastrados
Resumo Inglês:
The Borborema Province (NE Brazil) has a long history of deformation, magmatism and metamorphism
during the Precambrian Eon. Thus, it represents a natural laboratory to investigate widely developed
ductile-deformation markers, such as major fold belts and large-scale shear zones. This paper descri
-bes the structural evolution of a complex folded area of the Alto Moxotó Terrane, Central Borborema
Province. In this region, para-derived rocks of the Sertânia Complex are intruded by orthogneisses and
migmatitic orthogneisses. The Geophysical magnetometric expressions of the Borberma Province are
characterized by strong aligned and folded magnetic lineaments and integrated structural analysis, allo
-wed us to identify three ductile deformation episodes. Brittle tectonics is also present, but not described.
D1 stage represents the basement structural framework restricted to local structural windows of ancient
orthogneisses and migmatites that are not mappable at the work scale. D2 deformation is widespread
throughout the Central Borborema Province, producing nappes that mark top-to-NW tectonic vergence.
Foliation and lineation attitudes are compatible with progressive deformation from tangential to strike
-slip tectonics (i.e. D2 to D3). The latter is associated with the NE-SW Xinxó and Congo-Cruzeiro do
Nordeste sinistral strike-slip shear zones, producing refold patterns that resemble Type-3 interference
geometry. Based on airborne magnetic geophysical imaging interpretations and mesoscopic observa
-tions, we suggest that progressive deformation strongly affected the region and overprinted at large
scale early formed rocks.