Bezerra, Francisco Hilario RegoMaciel, Ingrid Barreto2020-11-282020-11-282020-09-30MACIEL, Ingrid Barreto. Silicificação hidrotermal e bandas de deformação: influência na arquitetura interna de falhas na Bacia Rio do Peixe, Brasil. 2020. 107f. Tese (Doutorado em Geodinâmica e Geofísica) - Centro de Ciências Exatas e da Terra, Universidade Federal do Rio Grande do Norte, Natal, 2020.https://repositorio.ufrn.br/handle/123456789/30754The present work investigates the formation and compartmentalization processes of the fault zones and hydrothermal silicification in the Rio do Peixe Basin, Brazil, observing these processes' impact on the host siliciclastic rocks. For this, we mapped six outcrops with the aid of unmanned aerial vehicle (UAV), structural mapping, petrography, scanning electron microscopy (SEM), spectroscopy dispersive energy (SDE), X-ray diffractometry (XRD), and fluid inclusion analyses. We observed that the fault zones have a core with a high degree of cataclase, reducing the size of the grains, primary and secondary porosity. Next to the core, a damage zone is characterized by single deformation bands or clusters, where the content of clay minerals vary significantly. The borders fault zones have silicification bands up to 250 m thick. Throughout these bands, silicification varies in intensity and can show a static or dynamic pattern. Deformation bands, hydraulic gaps close to the main fault plane, and silicified basement rocks with quartz veins are found in these places. Within the primary and secondary pores, there are occurrences of newly formed minerals such as kaolinite, chalcedony, apatite, and barite, resulting from the interaction between the hydrothermal fluid and the host rock. Silicification is associated with ascents of hydrothermal fluids along the deepest faults, varying in temperature conditions between 89 ° C and 240 ° C and 30-80 Mpa pressure. From the results obtained, we conclude that the composition of the framework and the clays' mineralogy do not vary along the fault zone, despite the content of clay minerals being systematically lower in the most deformed rocks. They have a weathering origin, unrelated to the fault activity. On the other hand, the silicification of the border faults is linked to the fault dynamics, because they suffer reactivation from the rise of hydrothermal fluids formed at high pressures and temperatures. Therefore, the cataclase and the hydrothermal silicification processes have important implications for aquifers and hydrocarbon reservoirsAcesso AbertoBandas de deformaçãoDeformation bandsSilicificação hidrotermalBacia Rio do PeixeHydrotermal silicificationdoctoralThesis