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Abstract Geological structures influence the formation and evolution of sedimentary rocks. The Minas do Camaquã fault zone is a primary structure of the Camaquã Basin, controlling the uplift of the ore-bearing units of the Santa Bárbara Group. To the south of the Camaquã River, the fault zone deforms alluvial and eolian sequences attributed either to the Santa Bárbara or Guaritas groups. In this study, a facies and petrographic composition and diagenetic analysis are presented to understand the evolution of the fault zone. Facies analysis was accomplished using high-resolution orthophoto mosaics and field surveys. Seven sedimentary facies were defined, grouped into three facies associations. Facies associations correspond to a succession of climate-influenced depositional environments. The transition from humid to dry conditions occurs from a fluvial (facies association 1) to eolian environments (facies association 2). These deposits are overlaid at the top by a high energy environment deposits characterized by amalgamated gravelly and sandy bodies, corresponding to an alluvial environment (facies association 3). Despite a small compositional variation, sandstones present a continental block provenance which may be related to mixed anorogenic or orogenic provenance. Diagenetic features are similar in the three facies associations, suggesting the same burial history for the sedimentary deposits separated by the fault zone. The Minas do Camaquã fault zone in the study area is an intraformational structure, as analyzed sequences are attributed to the Guaritas Group, implying a relatively high degree of deformation late after its deposition. Highlights • Fault zone separates steeply inclined from horizontal sequences. • Three facies associations were interpreted from field and remote sensing data. • Sandstones detrital composition indicates continental block and mixed provenance. • Fault zone does not limit diagenetic variations suggesting a single burial history. • Units separated by the fault zone correspond to the Guaritas Group. [ABSTRACT FROM AUTHOR]

The Espinhaço Basin is one of the largest Precambrian intracratonic basins in the Brazilian Shield, and it comprises three tectonostratigraphic megasequences, i.e., the Lower, Middle, and Upper Espinhaço sequences, deposited from 1.8 to 1.68 Ga, 1.6 to 1.38 Ga, and 1.2 to 0.9 Ga, respectively. Each megasequence contain detrital materials derived from the denudation of basement and/or cover units and can be used to decipher the paleogeographic evolution of the São Francisco Craton, together with the vertical and lateral stratigraphic architecture. Sandstone compositions and detrital zircon U–Pb ages and Lu–Hf isotopes from the Middle and Upper Espinhaço sequences were investigated, in conjunction with stratigraphic data, to reveal distinct provenance patterns. Sandstones in the lower units of the Middle Espinhaço sequence were recycled from sedimentary sources and were found to contain Paleoproterozoic zircon grains, either juvenile or evolved from Mesoarchean or Neoarchean crustal sources. This pattern is succeeded by sandstones derived from recycled sedimentary sources that contain juvenile and remelted zircon grains formed in the Paleoarchean, Neoarchean, and Paleoproterozoic eras. The overlying units of the Middle and Upper Espinhaço sequences include significant inputs from Statherian and Calymmian zircon grains, in addition to the Archean and Paleoproterozoic grains. This points to both a stratigraphic inversion of the source area due to the denudation of Archean basement terrain in the lower sections and a change of provenance with the input of Statherian and Calymmian zircons in the upper sections. In addition, the ages and Hf isotopic compositions of zircon grains older than 1.8 Ga match the evolution of the continental crust within the São Francisco Craton. A possible chronocorrelation between the late Paleoproterozoic to Mesoproterozoic cratonic sequences in the Congo–São Francisco Craton and those sequences preserved within the Fennoscandian and Indian shields as well as in the North American, West Australian, and North China Cratons implies similar evolutions for these regions after ca. 1.8 Ga. Such a similarity is probably related to the evolution of the Columbia supercontinent and its transition to the Rodinia supercontinent. [ABSTRACT FROM AUTHOR]

The structural framework and tectonic evolution of the sedimentary basins along the eastern margin of the South American continent are closely associated with the tectonic framework and crustal heterogeneities inherited from the Precambrian basement. However, the role of NW-SE and NNW-SSE structures observed at the outcropping basement in Southeastern Brazil and its impact over the development of those basins have not been closely investigated. In the continental region adjacent to the Campos Basin, we described a geological feature with NNW-SSE orientation, named in this paper as the Alegre Fracture Zone (AFZ), which is observed in the onshore basement and can be projected to the offshore basin. The main goal of this work was to study this structural lineament and its influence on the tectonic evolution of the central portion of the Campos Basin and adjacent mainland. The onshore area was investigated through remote sensing data joint with field observations, and the offshore area was studied through the interpretation of 2-D seismic data calibrated by geophysical well logs. We concluded that the AFZ occurs in both onshore and offshore as a brittle deformation zone formed by multiple sets of fractures that originated in the Cambrian and were reactivated mainly as normal faults during the rift phase and in the Cenozoic. In the Campos Basin, the AFZ delimitates the western side of the Corvina-Parati Low, composing a complex fault system with the NE-SW faults and the NW-SE transfer faults. [ABSTRACT FROM AUTHOR]