Gravity surveys and 3D integrated model with magnetic and geological data of the granite-greenstone terrane in Pitangui Synclinorium, NW of the Quadrilátero Ferrífero (MG, Brazil)

Matos, Caio Alencar de; Amorim, Paulo Henrique; Marinho, Marcelo; Marangoni, Yára Regina; Araújo, Joanna Chaves Souto; Oliveira, Roberto Gusmão de; Lombello, Júlio César

doi:10.1016/j.jsames.2022.103828

Cited by 6 publications

(5 citation statements)

References 34 publications

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“…Seismic data suggest that this unit reaches ca. 400 m depth, with its thickness increasing towards the north (Reis et al 2017;Matos et al 2022).…”

Section: Bambuí Groupmentioning

confidence: 99%

“…The Neoproterozoic sedimentary rocks that cover the Archean Pitangui greenstone belt belong to the Bambuí Group (Reis et al 2017;Matos et al 2022). This unit is composed of shales, carbonate rocks, sandstones and subordinate coarse siliciclastic rocks (Dardenne 1978(Dardenne , 1981.…”

Section: Geological Contextmentioning

confidence: 99%

“…Its eastern limit is marked by a Neoarchean granitic dome (Florestal Batholith) and its southeast continuity is represented by the Mateus Leme and Souzas synclinoriums. At its northern limit, the Pitangui Synclinorium deflects in a N-S trend under Bambuí Group cover (Matos et al 2022).…”

Section: Stratigraphy Of the Pitangui Synclinoriummentioning

confidence: 99%

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Stratigraphy of the Pitangui Synclinorium, northwest of the Quadrilátero Ferrífero mineral province - Brazil: magmatism and sedimentation from Archean to Neoproterozoic

Marinho¹,

Magalhães²,

Lombello³

et al. 2023

JGSB

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The Pitangui Synclinorium is located in the northwestern portion of the Quadrilátero Ferrífero mineral province, São Francisco Craton, in southeast Brazil. It corresponds to a NW-SE-trending synformal structure composed of an Archean greenstone belt sequence, which is covered by Paleoproterozoic metasedimentary rocks to Neoproterozoic sedimentary rocks, and surrounded by Archean granitegneiss complexes. This study reports the first detailed 1:25,000 scale geological mapping in the Pitangui Synclinorium and provides cartographic, stratigraphic and petrographic improvements, allowing the formalization of its lithostratigraphic units and unraveling the sedimentary and volcanic depositional environments. The Archean Pitangui greenstone belt occurs in most parts of the homonymous synclinorium, and is subdivided into the Pitangui Group and the Antimes Formation. The metavolcanosedimentary sequence of the Pitangui Group comprises basal mafic/ultramafic metavolcanic rocks with subordinate felsic/intermediate metavolcanic and metavolcaniclastic rocks of the Rio Pará Formation, suggesting a bimodal volcanism. It is followed by volcanogenic and chemical metasedimentary rocks of the Rio São João Formation, and pelitic to sandy metasedimentary rocks of the Onça do Pitangui Formation deposited in subaqueous environments mainly corresponding to submarine fan systems. The occurrence of clastic rocks increases towards the top of the sequence. The Antimes Formation comprises quartzites and metaconglomerates related to fluvial and fan delta depositional environments. The Pitangui greenstone belt is overlapped, in the central and northwest regions of the study area, by the Fazenda Tapera Formation, a Paleoproterozoic siliciclastic package containing arkosic metasandstones, metagreywackes and metarhythmites deposited in a shallow marine environment. Subordinated tuff layers occur as ash/fall deposits from distal volcanism. Neoproterozoic clastic-chemical sedimentary rocks of the Bambuí Group cover the northern portions of the synclinorium, and are mainly composed of diamictites, limestones, marls and rhythmites from the Carrancas (lacustrine or restricted marine), Sete Lagoas (shallow marine) and Serra de Santa Helena formations (deep water grading to prodelta and delta front).Stratigraphy of the Pitangui Synclinorium, northwest of the Quadrilátero Ferrífero mineral province -Brazil: magmatism and sedimentation from Archean to Neoproterozoic Accepted manuscript -Uncorrected pre-proof This is a PDF file containing an unedited and non-definitive version of a manuscript that has been accepted for publication by the Journal of the Geological Survey of Brazil -JGSB, which serves to provide early visibility of the article. Being an uncorrected preproof version, errors may appear during the production process (language review, formatting and proof review), and these can affect the final content of the article and all legal disclaimers (https://jgsb.cprm.gov.br/index.php/journal/6).

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“…Seismic data suggest that this unit reaches ca. 400 m depth, with its thickness increasing towards the north (Reis et al 2017;Matos et al 2022).…”

Section: Bambuí Groupmentioning

confidence: 99%

Section: Geological Contextmentioning

confidence: 99%

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Stratigraphy of the Pitangui Synclinorium, northwest of the Quadrilátero Ferrífero mineral province - Brazil: magmatism and sedimentation from Archean to Neoproterozoic

Marinho¹,

Magalhães²,

Lombello³

et al. 2023

JGSB

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“…In Archean terranes of large cratons, positive gravity anomalies are generally associated with iron formations and mafic/ultramafic magmatism, and negative anomalies with felsic intrusive suites (e.g., Peschler et al 2004;Gwavava and Raganai, 2009;Ramotoroko et al 2016;Matos et al 2022). As discussed above for the Borborema Province, irrespective of what the dominant lithological composition may be, all Archean nuclei show positive gravity residual anomalies (Figure 6E).…”

Section: Gravity Signatures Of the Archean Units And Their Sourcesmentioning

confidence: 99%

“…Geophysical methods to investigate Archean granitegreenstone belts in large cratons have been frequently applied, too (e.g., House et al 1999;Silva et al 2003;Gwavava and Raganai 2009;Raganai 2012;Matos et al 2022), due to the fact that a large part of global exploration and production of Fe, Cu, Au, Ni, IOCG, PGE-Cr, Sn and diamond occur in these belts (e.g., Groves and Barley 1994;Grainger et al 2008;Angerer and Hagemann 2010;Xavier et al 2012). Specifically, geophysical methods have been employed to characterize tectonic structures and to obtain two-and three-dimensional models for greenstone belts and associated magmatism (e.g., Peschler et al 2004;Silvennoinen and Kozlovskaya 2007;Matos et al 2022). Petrophysical contrasts between rocks with different lithological compositions have favored the use of indirect investigation methods, which may reduce the cost of mineral exploration (Schodde 2020).…”

Section: Introductionmentioning

confidence: 99%

Gamma-ray spectrometry, magnetic and gravity signatures of Archean nuclei of the Borborema Province, Northeastern Brazil

Oliveira,

Domingos,

Medeiros

et al. 2024

JGSB

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Gamma-ray spectrometry, as well as magnetic and gravity data, are used to investigate the geophysical signatures of the Archean nuclei of the Borborema Province. Natural radioactivity, magnetic anomalies, and residual Bouguer gravity anomalies of the Archean nuclei exhibit distinct signatures in relation to adjacent Proterozoic domains. Gamma-ray spectrometry data reveal eTh enrichment in relation to K and eU contents in Archean units. Assuming that K and U were the dominant isotopes, this relative enrichment of eTh can be explained by the fact that Th radioisotopes have a longer half-life than the other two radionuclides and that 4.56 Ga has elapsed since Earth's formation. The intensity of the total magnetic gradient in Archean units is greater than in Proterozoic units in most nuclei. The Archean units underwent deformation and metamorphism in the Brasiliano/Pan-African Orogeny; therefore, the magnetic characteristics now observed in Archean mafic-ultramafic rocks, iron formations and gneissmigmatite complexes are the joint result of their primary properties and the superposed effects of the orogeny. All Archean nuclei of the Borborema Province show positive residual Bouguer gravity anomalies. This could be due to the conservation of the main petrophysical properties of the Archean lithosphere, and their preservation during the intense granitization that occurred in the Brasiliano/Pan-African Orogeny. As magnetic and gravity methods provide information from depth, it is possible to infer the continuity of some Archean nuclei beyond the limits established by surface geological data. Based on these results, it will be possible to use geophysical signatures to investigate the possible existence of unknown Archean units in the province.

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Exploring Fault Plane Geometry through Metaheuristic Bat Algorithm (MBA) Analysis of Potential Field Data: Environmental and Engineering Applications

Essa,

Diab

2024

Rock Mech Rock Eng

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By integrating inversion techniques with modeling data of the Earth’s passive potential field, encompassing gravity and magnetic fields, we can enhance our understanding of subsurface structural features, particularly faults, thereby contributing to advancements in earth science and environmental studies. Metaheuristic algorithms have gained prominence as global optimization tools, with increasing utilization for optimizing complex systems. This study proposes the utilization of the Metaheuristic Bat Algorithm (MBA), inspired by the echolocation capabilities of bats, to efficiently search for optimal solutions. The MBA method aims to minimize a predefined objective function, leading to the identification of fault-path parameters once the global optimum solution is attained. This approach offers a systematic means of evaluating fault characteristics without requiring prior domain knowledge. Application of the MBA methodology to potential field data facilitates the estimation of fault dimensions, including depth, origin, and dipping angle. Through rigorous testing on diverse simulated datasets with varying noise levels, the MBA approach demonstrates high precision and consistency in fault characterization. Moreover, field applications conducted in the USA, Egypt, Australia, and India validate the efficacy of the MBA scheme in earth science and engineering investigations. The inversion results obtained using the MBA approach align closely with drilling data, geologic observations, and existing literature, underscoring its reliability and utility in subsurface analysis.

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Gravity surveys and 3D integrated model with magnetic and geological data of the granite-greenstone terrane in Pitangui Synclinorium, NW of the Quadrilátero Ferrífero (MG, Brazil)

Cited by 6 publications

References 34 publications

Stratigraphy of the Pitangui Synclinorium, northwest of the Quadrilátero Ferrífero mineral province - Brazil: magmatism and sedimentation from Archean to Neoproterozoic

Stratigraphy of the Pitangui Synclinorium, northwest of the Quadrilátero Ferrífero mineral province - Brazil: magmatism and sedimentation from Archean to Neoproterozoic

Gamma-ray spectrometry, magnetic and gravity signatures of Archean nuclei of the Borborema Province, Northeastern Brazil

Exploring Fault Plane Geometry through Metaheuristic Bat Algorithm (MBA) Analysis of Potential Field Data: Environmental and Engineering Applications

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