Produção Nacional
The Piúma lineament, southern Espirito Santo: structural expression and tectonic significance
2016; Sociedade Brasileira de Geologia; Volume: 46; Issue: 4 Linguagem: Inglês
10.1590/2317-4889201620150038
ISSN2317-4889
AutoresFernanda Silva Lourenço, Fernando F. Alkmim, Mario Araújo, Marco Antônio Thoaldo Romeiro, Gabriel Corrêa de Matos, Álvaro Penteado Crósta,
Tópico(s)Geological and Geochemical Analysis
ResumoABSTRACT: The Piúma lineament, located in the Southern Espírito Santo State, Brazil, is one of the most prominent linear morphostructural features of the northern Mantiqueira Province. The lineament stands out in satellite images and topographic maps, extending for about 70 km in a N50°W direction, between the towns of Iconha and Conceição do Castelo (Espírito Santo). In order to investigate the nature and role played by the Piúma lineament in the tectonic evolution of the Mantiqueira Province and adjacent Campos Basin, we carried out a detailed structural analysis based on fieldwork, as well as geophysical data processing and interpretation. The results we obtained indicate that the Piúma lineament is a brittle shear zone characterized by N50W-trending and SW-dipping shear fractures, faults and joints. These structures record two distinct and incompatible motions, thereby recording the operation of two tectonic regimes: NNE-SSW extension and E-W transtension. Comparing our results with the literature on the Southeastern Brazilian Continental Margin, we conclude that the Piúma lineament more likely developed after the Ediacaran Brasiliano orogenic event in response to an NNE-SSW extension, experiencing later a reactivation as normal dextral to dextral transtensional zone, probably in connection with the South Atlantic rifting in the Lower Cretaceous.
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