Early to late Neoproterozoic subduction-accretion episodes in the Cariris Velhos Belt of the Borborema Province, Brazil: Insights from isotope and whole-rock geochemical data of supracrustal and granitic rocks

Santos, Lauro Cézar Montefalco de Lira; Dantas, Elton Luiz; Cawood, Peter A.; Lages, Geysson de Almeida; Lima, Haroldo Monteiro; Santos, Edilton José dos; Caxito, Fabrício de Andrade

doi:10.1016/j.jsames.2019.102384

Cited by 39 publications

(16 citation statements)

References 128 publications

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“…869 Ma in the eastern Transversal Zone (Neves et al 2015) seem to be part of a middle Tonian rifting event similar to that discussed for the Riacho do Pontal area. In addition, based on the trace-element and isotope characteristics of the São Caetano supracrustal sequence of the Alto Pajeú Domain, Santos et al (2019) described an extensional setting interpreted as a post-Cariris event at ca. 858 Ma.…”

Section: Discussionmentioning

confidence: 99%

New U-Pb (SHRIMP) and first Hf isotope constraints on the Tonian (1000-920 Ma) Cariris Velhos event, Borborema Province, NE Brazil

et al. 2020

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Orthogneisses associated with metavolcanosedimentary successions related to the 1000-920 Ma Cariris Velhos event occur mainly in a ca. 700 km-long sigmoidal-shaped belt that crosscuts the Transversal Zone of the Borborema Province and extends to the fold belts located in its southern or external zone (part of the Riacho do Pontal and Sergipano orogens). Despite its importance, the tectonic setting and the role of those rocks in the geological evolution of the Borborema Province are contentious and not yet well understood. New zircon U-Pb SHRIMP data on an augen-gneiss sill of the Afeição Suite intruding mica-schists mapped as part of the Santa Filomena Complex yielded a Concordia Age of 974 ± 11 Ma, indicating that at least part of the metasedimentary rocks in the internal zone of the Riacho do Pontal Orogen are Tonian or older and possibly related to the Cariris Velhos event. Hf-in-zircon isotope data are presented for the first time for Cariris Velhos-related ortho-derived rocks of the Afeição Suite. Analyzed samples yielded εHf(t) in a narrow range between-1.51 and +2.41, with associated T DMHf of 1.6-1.4 Ga, similar to previously obtained Nd isotope data with εNd(t) =-1.0 to +3.1 and T DMNd of 1.5-1.2 Ga. A possible scenario to explain both the geochemical features and the moderately juvenile to slightly evolved, near-chondritic Hf and Nd isotope signatures is a continental arc setting, where fractionated melts produced in the supra-subduction zone mantle wedge carrying a Tonian juvenile signature became contaminated with discrete amounts of Archean-Paleoproterozoic continental crust during ascent, producing Mesoproterozoic model ages which represent the mixture of those two end-members.

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Section: Discussionmentioning

confidence: 99%

New U-Pb (SHRIMP) and first Hf isotope constraints on the Tonian (1000-920 Ma) Cariris Velhos event, Borborema Province, NE Brazil

et al. 2020

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“…Other evidence for Neoproterozoic plate tectonic processes in the BP are more contentious and highly discussed , Caxito et al 2020b. For example, the Cariris Velhos belt of the Transversal Zone has been proposed as an accretionary orogen, developed in a continental arc setting (Santos et al 2010(Santos et al , 2019, including metavolcanics, metasedimentary, and metaplutonic members. Recently, Fe-Ti-V mineralized metamafic-ultramafic rocks that occur in the Floresta Region (Alto Pajeú Terrane of the Central Borborema Province) were dated at ca.…”

Section: The Case For An Accretionary Modelmentioning

confidence: 99%

Accretionary models for the Neoproterozoic evolution of the Borborema Province: advances and open questions

Santos

Caxito

2021

Braz. J. Geol.

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The current knowledge on the accretionary evolution of the Borborema Province is evaluated considering recently published data and interpretations. Early to late Neoproterozoic eclogite, ophiolite, and magmatic arc remnants have been documented and point to oceanic crust consumption. Isotopic contrasts as well as geophysical anomalies across the major domain boundaries are suggestive of collisional sutures and a speculative model of terrane accretion is presented here. On the other hand, the lack of concise evidence for some of the proposed deep-seated structures as well as putative lithospheric continuity in both sides of it suggest reworking of previously continuous lithosphere through intracontinental deformation in localized sectors of the province interior. It is patent that one model does not preclude the other and available evidence so far has triggered the emergence of conciliatory proposals for the Neoporterozoic history the Borborema Province.

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“…Prior to the opening of the Atlantic Ocean, the province has had crustal continuity into the Oubanguides, Central Africa and Dahomeyides belts through Togo, Benin, Nigeria and Cameroon (Caxito et al, 2020a and references therein). In a simplified way, the overall configuration of this province includes Archean and Paleoproterozoic gneissic-migmatitic domains (e.g., Santos et al, 2015;Ferreira et al, 2020) that are bounded or interleaved with Neoproterozoic supracrustal sequences (e.g., Neves et al, 2017;Santos et al, 2019) and granitic domains that represent remnants of accretion episodes during the assembly of West Gondwana (Figure 1B; Brito Neves et al, 2000;Caxito et al, 2020b).…”

Section: Geological Settingmentioning

confidence: 99%

“…The related rocks are intrusive in ca. 858 -806 Ma metavolcanosedimentary rocks of the São Caetano Complex (Guimarães et al, 2012;Santos et al, 2019). Early Neoproterozoic rocks are related to the Cariris Velhos Orogeny (960 -920 Ma), being grouped with the cumulatic/ophiolitic Serrote das Pedras Pretas Suite, as well as a series of arc-related calc-alkaline metagranites, orthogneisses and metavolcanic rocks (Kozuch, 2003;Santos et al, 2010).…”

Section: Geological Settingmentioning

confidence: 99%

Exploring the relationships between shear zones and granites: field and microstructural data for contrasting case studies of the Borborema Province (NE Brazil)

Santos

Viegas

2021

Geol. USP. Sér. Cient.

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We discuss meso- and microstructural features of granites closely related to strike-slip shear zones in the Borborema Province, NE Brazil. The Riacho do Icó stock is an en-cornue intrusion aged at ca. 607 Ma. Magmatic fabric is recorded in the core of the granite, whilst increasing deformation is marked by the development of mylonitic fabrics towards the Afogados da Ingazeira shear zone, including magmatic foliation and lineation rotation. Early recrystallization of quartz and K-feldspar crystals is widespread as a fabric with well-developed granoblastic polygonal textures and lobate subgrain boundaries, heterogeneously deformed lenses and ameboid quartz ribbons, typical of igneous rocks submitted to deformation in deep crustal levels. On the other hand, the Espinho Branco-Santa Luzia leucogranitic belt is hosted along the Patos Lineament, aged between the ca. 575 – 565 Ma interval. These rocks show discordant relationships with the host migmatites and the main deformational fabric is characterized by a dominant magmatic foliation that is locally overprinted by structures that are typical of solid-state flow. Quartz melt pockets and interstitial quartz grains filling fractures in feldspar clasts are common. Such characteristics are compatible with granites that were injected in the continental crust along planar anisotropies (i.e., shear zones) formed during the late-stage partial melting events that originated the migmatites of the area. The case studies are proxies in the understanding of different episodes of magma emplacement along shear zones in this part of West Gondwana.

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Early to late Neoproterozoic subduction-accretion episodes in the Cariris Velhos Belt of the Borborema Province, Brazil: Insights from isotope and whole-rock geochemical data of supracrustal and granitic rocks

Cited by 39 publications

References 128 publications

New U-Pb (SHRIMP) and first Hf isotope constraints on the Tonian (1000-920 Ma) Cariris Velhos event, Borborema Province, NE Brazil

New U-Pb (SHRIMP) and first Hf isotope constraints on the Tonian (1000-920 Ma) Cariris Velhos event, Borborema Province, NE Brazil

Accretionary models for the Neoproterozoic evolution of the Borborema Province: advances and open questions

Exploring the relationships between shear zones and granites: field and microstructural data for contrasting case studies of the Borborema Province (NE Brazil)

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