Isotopic and geochemical characterization of the metavolcano-sedimentary rocks of the Jirau do Ponciano Dome: A structural window to a Paleoproterozoic continental arc root within the Southern Borborema Province, Northeast Brazil

Lima, Haroldo Monteiro; Pimentel, Márcio Martins; Santos, Lauro Cézar Montefalco de Lira; Dantas, Elton Luiz

doi:10.1016/j.jsames.2018.12.002

Cited by 20 publications

(4 citation statements)

References 44 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Borborema Province is in the Northeastern portion of Brazil and represents one of the major Neoproterozoic structural provinces of South America (Almeida et al 1981). It comprises basement domains formed by Paleoproterozoic gneissic and migmatitic rocks and some Archean nuclei (Dantas et al 2013, Costa et al 2015, Santos et al 2015, 2017a, Lima et al 2019) that are interleaved or partially covered by Meso-to Neoproterozoic metasedimentary and metavolcanic sequences and terranes, which are later intruded by several Ediacaran granitic plutons associated with the Brasiliano Orogeny (Van Schmus et al 1995, 2016, Neves et al 2006, Sial & Ferreira 2016, Basto et al 2019, Santos et al 2018. Based on the general displacement of the major shear zones (i.e., Patos and Pernambuco lineaments), the province is divided into three subprovinces: Northern, Transversal, and Southern (Santos et al 2000, as seen in Fig.…”

Section: Geological Settingmentioning

confidence: 99%

The role of airborne geophysics in the investigation of gold occurrences in the Itapetim Region, Borborema Province, Northeast Brazil

2019

View full text Add to dashboard Cite

We present a combined analysis of airborne geophysical data (magnetics and gamma-ray spectrometry) and field aspects of Itapetim lode gold district region, aiming to identify structurally deformed and hydrothermally altered zones, which are suggestive of gold mineralized sectors. The main geophysical lineaments are oriented in the NE-SW and E-W directions and display a clear correlation with the major gold-bearing structures in the region. In the magnetic maps, the key pathfinder for gold occurrences is their association with strongly magnetized areas positioned along the Itapetim Shear Zone and outer contour of Teixeira Batholith. In the field, such structures are materialized in protomylonitic and mylonitic rocks that present evidence of ductile and brittle deformation, whereas kinematic criteria are suggestive of a transpressional tectonic regime. In addition, the main radiometric pattern is characterized by K enrichment, which is correlated with a hydrothermal mineral assemblage dominated by quartz, potassium feldspar, and tourmaline. Based on the obtained data integration, we produced an integrative map and located ten new target areas of possible gold mineralization, which is correlative to other well-known lode deposits in Northeast Brazil and Africa.

show abstract

Section: Geological Settingmentioning

confidence: 99%

The role of airborne geophysics in the investigation of gold occurrences in the Itapetim Region, Borborema Province, Northeast Brazil

2019

View full text Add to dashboard Cite

show abstract

“…The Nicolau-Campo Grande complex consists of a Paleoproterozoic meta volcano-sedimentary sequence that occurs interspersed in the leucocratic orthogneisses banded to migmatitic of the Jirau do Ponciano Complex (Mendes et al, 2009;Mendes e Brito, 2016). The studies of Lima et al (2019) indicated that the Nicolau -Campo Grande complex is the core of a Paleoproterozoic magmatic arc, which together with the Jirau do Ponciano Complex was raised by thrusts during the Brasiliano Orogeny in a gneissic-migmatitic dome structure.…”

Section: Marancó-poço Redondo Domainmentioning

confidence: 99%

Deep crustal structure of the Sergipano Belt, NE-Brazil, revealed by integrated modeling of gravity, magnetic, and geological data

Oliveira¹,

Domingos²,

Medeiros³

2023

JGSB

View full text Add to dashboard Cite

The Sergipano Belt is located in the Southern Subprovince of Borborema Province in the Northeast of Brazil. Its tectonic framework was consolidated in the Pan-African-Brasiliano Orogeny at the end of the Neoproterozoic. The most recent geological models indicate that its evolution occurred over a complete Wilson cycle. Gravimetric and magnetic data profiles that crossed the Sergipano Belt from south to north were modeled jointly by the direct method to provide a 2D view of the crust framework. The modeling process was linked and supported by the use of geological data and models. The result revealed the deep structure of the crust and identified the geometry of the main geological domains to the depth of Moho's discontinuity. The folds and thrusts toward the São Francisco Craton are a persistent and deep feature in the Southern crust of the Sergipano Belt. The general tectonic context of the models is compatible with the subduction and collision of the São Francisco Paleo-Plate under the Pernambuco-Alagoas Superterrane, sutured in the Shear Zone of São Miguel do Aleixo. The presence of dense blocks at the base of the crust was interpreted as layers of ophiolites placed by obduction. The metasediments of the Vaza Barris and Macururé Domains are tabular bodies with thicknesses lower than 5 km, which dip horizontally or at a low angle on the flanks of the shear zones. Small vertical bodies of lower density within the Macururé Domain have correlation with granitic intrusions. In the Canindé Domain there is a dense layer in the lower crust that was interpreted as the relicts of the oceanic crust that based a backarc basin. The granitic bodies modeled north of the Canindé Domain and correlated with the Serra do Catu batholith in Pernambuco-Alagoas Superterrane, may be the record of subduction of this crust to the north. The data and models revealed geophysical differences between the Jirau do Ponciano, Coruripe River Domains and the crust north of the Palmeira dos Índios Shear Zone. These terrains are separated by shear zones with evident expression in gravimetric and magnetic data. However, the existence of Neoproterozoic metasedimentary supracrustal rocks partially covering the domains and zones and borderline shear indicates that the junction among these blocks occurred before the deposition of Neoproterozoic sediments.Deep crustal structure of the Sergipano Belt, NE-Brazil, revealed by integrated modeling of gravimetric, magnetic, and geological data 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).

show abstract

“…The Jirau do Ponciano dome, ~200 km north of the São Francisco Craton margin is dominated by high‐grade orthogneisses interleaved with amphibolite facies metavolcanic rocks and amphibolites (Mendes et al, 2009). Based on geochemistry and zircon dating of metavolcanic rocks, Lima et al (2019) proposed that the Jirau do Ponciano dome comprises a TTG association related to a 2.1–2.0 Ga magmatic arc.…”

Section: Geological Backgroundmentioning

confidence: 99%

Ultrahigh‐temperature Palaeoproterozoic rocks in the Neoproterozoic Borborema Province, implications for São Francisco Craton dispersion in NE Brazil

Tesser¹,

Ganade

Weinberg

et al. 2021

Journal Metamorphic Geology

View full text Add to dashboard Cite

This work reports on the first identification of sapphirine‐bearing ultrahigh‐temperature (UHT) metamorphic rocks within the Borborema Province, in NE Brazil. The investigated UHT diatexites outcrop in the Arapiraca Complex, a high‐grade Palaeoproterozoic block embedded within the Neoproterozoic metavolcano‐sedimentary sequence of the Sergipano fold‐and‐thrust belt. A sapphirine‐bearing diatexite sample preserves two distinct residual mineral associations as inclusions in cordierite poikiloblasts: a volumetrically dominant silica‐saturated, garnet–sillimanite–orthopyroxene–quartz domain, and a restricted silica‐undersaturated, sapphirine–magnetite–spinel–corundum domain. Phase equilibrium modelling for the whole‐rock bulk composition constrains the reactions preserved in the silica‐saturated domain, which, coupled with reintegrated ternary feldspar thermometry and Al‐in‐orthopyroxene thermobarometry, indicates peak UHT metamorphism occurring at ~970°C/8.5 kbar followed by a clockwise near isobaric cooling stage crossing the H2O‐undersaturated solidus at ~910°C/7.7 kbar. The T–MSiO2 and P–T phase equilibrium models reveal that the stabilization of magnetite‐spinel in the silica‐undersaturated domain can be a product of domanial SiO2‐depletion ascribed to inherited compositional banding and progressive melt‐loss episodes. The appearance of sapphirine as thin coronae around previously formed magnetite‐spinel cores requires an increase in the bulk silica content during retrograde metamorphism. This was driven by variable degrees of chemical interaction between the silica‐undersaturated domain and trapped silica‐rich leucosomes. U–Pb dating of zircon coupled with trace element behaviour records the timing of melt crystallization between ca. 2.03 and 1.96 Ga, after peak UHT metamorphism and supporting a protracted, ca. 70 My period of melt presence in the crust. The UHT metamorphism in the Arapiraca Complex is related to a contemporaneous UHT event recorded within the São Francisco Craton and more broadly coincides with high geothermal gradients at ca. 2.0 Ga linked to the formation of the Columbia supercontinent. The integration of new petrological and geochronological data indicates that the Arapiraca Complex is a continental ribbon pulled away from the São Francisco–Congo palaeocontinent possibly during the early Neoproterozoic intermittent rifting events and opening of the Sergipano oceanic basin between ca. 0.98–0.74 Ga. During the late Neoproterozoic at ca. 0.63–0.57 Ga, the Arapiraca Complex continental ribbon was thrusted back onto the northern margin of the São Francisco Craton as an inlier of the Sergipano fold‐and‐thrust belt.

show abstract

Isotopic and geochemical characterization of the metavolcano-sedimentary rocks of the Jirau do Ponciano Dome: A structural window to a Paleoproterozoic continental arc root within the Southern Borborema Province, Northeast Brazil

Cited by 20 publications

References 44 publications

The role of airborne geophysics in the investigation of gold occurrences in the Itapetim Region, Borborema Province, Northeast Brazil

The role of airborne geophysics in the investigation of gold occurrences in the Itapetim Region, Borborema Province, Northeast Brazil

Deep crustal structure of the Sergipano Belt, NE-Brazil, revealed by integrated modeling of gravity, magnetic, and geological data

Ultrahigh‐temperature Palaeoproterozoic rocks in the Neoproterozoic Borborema Province, implications for São Francisco Craton dispersion in NE Brazil

Contact Info

Product

Resources

About