Geometry, kinematics and geochronology of the Sertânia Complex (central Borborema Province, NE Brazil): Assessing the role of accretionary versus intraplate processes during West Gondwana assembly
Introduction
Since the recognition that the North American Cordillera grew westward by accretion of terranes with distinct origins (Coney et al., 1980), the concept of terrane-style tectonics has been widely applied to ancient orogenic belts whose topographic expression has been erased long ago (e.g., Williams and Hatcher, 1982, Vaughan et al., 2005, Cawood and Buchan, 2007, Yuan et al., 2007, Wilhem et al., 2012). Precambrian examples, amongst many others, include the Svecofennian orogen (Korja and Heikkinen, 2005), the 1.9 Ga accretionary phase of the Hudsonian Orogeny (Berman et al., 2007), the Racklan and Forward orogens in northwestern Canada (Furlanetto et al., 2013), and, in the Gondwana realm, the Neoproterozoic Arabian-Nubian shield (e.g., Johnson et al., 2011, Robinson et al., 2014) and the Tuareg shield (Black et al., 1994, Caby, 2003, Bosch et al., 2016). Interpreting an orogen as accretionary has wide implications concerning the tectonic setting, paleogeographic reconstructions, and crustal growth models (Cawood and Buchan, 2007). More recently, it has also been increasingly recognized that important intracontinental deformation may occur away from contemporary plate boundaries (Aitken et al., 2013), both in modern (Cunningham, 2005, De Grave et al., 2007, Li and Li, 2007) and in ancient orogens (Nyman et al., 1994, Hand and Sandiford, 1999, Haines et al., 2001, Dickerson, 2003, Ferguson et al., 2004, Faure et al., 2009, Raimondo et al., 2010, Howard et al., 2015). Furthermore, deformation driven by ocean closures and continental collisions may affect areas of preexistent crust previously located in an intracontinental setting (e.g., Avouac and Burov, 1996, Hoepffner et al., 2006, Kroner and Romer, 2013, Villaseca et al., 2015), including the destabilization of large cratonic segments during periods of supercontinent formation (Abdelsalam et al., 2002, De Waele et al., 2006, Liégeois et al., 2013).
In this paper, we discuss the role that accretionary and intraplate processes had in the Neoproterozoic tectonic evolution of the Borborema Province, northeastern Brazil (Fig. 1), during the assembly of West Gondwana. The Borborema Province shows a complex geological evolution, with records of deformation and magmatic events spanning most of the Precambrian (see reviews in Brito Neves et al., 2000, Van Schmus et al., 2008, Neves, 2003, Neves, 2015). The province is divided into three subprovinces by the Patos and Pernambuco shear zones systems: Northern, Central (or Transversal), and Southern (e.g., Brito Neves et al., 2000, Van Schmus et al., 2008, Neves, 2003, Neves, 2015) (Fig. 1b). There is now a consensus that the build-up of the Archean to Paleoproterozoic basement of the province involved the collage of juvenile island arcs and preexisting crustal blocks (Souza et al., 2007, Souza et al., 2016, Dantas et al., 2013, Van Schmus et al., 2008, Van Schmus et al., 2011, Neves et al., 2015a, Santos et al., 2015), and that the Neoproterozoic Brasiliano (=Pan-African) Orogeny resulted from convergence of the São Franscisco-Congo and Amazonian-West Africa cratons, although there is disagreement concerning the width of the oceans involved (Araújo et al., 2014, Neves, 2015). In the Central subprovince, the main discussion concerns the role of terrane assembly during the Neoproterozoic. In one view, its formation occurred via accretion of terranes during two orogenic events: Cariris Velhos in the Early Neoproterozoic (c. 1000–920 Ma) and Brasiliano in the Late Neoproterozoic to early Cambrian (c. 640–550 Ma) (Brito Neves et al., 1995, Brito Neves et al., 2000, Santos and Medeiros, 1999, Santos et al., 2010, Lages and Dantas, 2016, Padilha et al., 2016). Alternatively, the central portion of the Borborema Province is regarded as part of a larger Paleoproterozoic continent that underwent essentially intracontinental deformation during the Brasiliano Orogeny (Mariano et al., 2001, Neves, 2003, Neves, 2015, Da Silva Filho et al., 2014, Bastow et al., 2015, Dias et al., 2015). In this view, the Cariris Velhos event is interpreted as purely extensional, with contractional deformation and metamorphism only occurring during the Brasiliano Orogeny (Neves, 2003, Neves, 2015, Guimarães et al., 2012, Guimarães et al., 2016).
Santos (1995) and Santos and Medeiros (1999) proposed that the Central subprovince resulted from the collage of four terranes (here called domains), which are, from east to west: Rio Capibaribe, Alto Moxotó, Alto Pajeú and Piancó-Alto Brígida (Fig. 1c, inset). The Sertânia Complex (Fig. 1c) was one of the main elements used in support of this proposition (Santos et al., 2004). This complex consists dominantly of migmatized garnet-biotite gneisses that constitute the main metasedimentary unit of the Alto Moxotó domain. The inferred Paleoproterozoic age of deposition of the Sertânia Complex (Santos et al., 2004) would distinguish it from supracrustal sequences in the adjacent Rio Capibaribe and Alto Pajeú domains, which have, respectively, late Neoproterozoic and early Neoproterozoic deposition ages (Neves et al., 2006, Neves et al., 2009, Van Schmus et al., 2011, Guimarães et al., 2012, Brito Neves et al., 2013, Da Silva Filho et al., 2014). The samples dated by Santos et al. (2004) were collected in the easternmost part of the Alto Moxotó domain. Here we report the results of a structural, metamorphic and geochronological work conducted in the type area of the Sertânia Complex (Fig. 1c). We describe the deformation and metamorphism of this sequence, assess the age(s) of deposition by carrying out new U-Pb analyses of detrital zircons, and compare its tectonic evolution with that of the Surubim Complex in the Rio Capíbaribe Domain. Based on these data, we discuss the regional implications for the geological evolution of the Central subprovince and evaluate if it is better explained by an accretionary or an intracontinental model.
Section snippets
Geological setting and previous geochronology
The main structural feature of the Central subprovince is a network of E-W- to ENE-WSW-striking dextral and NNE-SSW- to NE-SW-striking sinistral shear zones (Fig. 1c). The proposed limit between the Alto Moxotó domain and the Rio Capibaribe domain corresponds to the sinistral Congo shear zone and the dextral Coxixola shear zone (Santos and Medeiros, 1999, Rodrigues and Brito Neves, 2008, Miranda, 2010, Santos, 2012). The boundary between the Alto Moxotó and Alto Pajeú domains is less
General geology
The study area is in the northern part of the Sertânia Sheet (SC.24-E-II), encompassing the homonymous city (Fig. 2). Metasedimentary rocks of the Sertânia Complex consist dominantly of stromatic migmatites with medium- to coarse-grained mesosome (Fig. 3a). The abundance of biotite and garnet (porphyroblasts up to 2 cm-wide; Fig. 3b) and the common occurrence of sillimanite (Fig. 3b) in the mesosome indicate that the protoliths were probably sediments with an important pelitic component.
Samples and methods
Five samples were collected for the geochronological study (Fig. 2). Three samples (SE-04, SE-10 and SE-12) are from the mesosome of migmatized paragneiss. The two others are from metamafic (SE-8A) and metasedimentary (SE-8B) rocks found tectonically intercalated in the same outcrop (Fig. 8a and b). The four metasedimentary samples are very similar, containing garnet porphyroblasts (0.3–1 cm in diameter) in a biotite-rich, medium-grained matrix. The geographical coordinates of the outcrops where
Linking deformation phases to kinematics
Field and map-scale structures show that the study area underwent polyphased deformation (D1–D5). Phase D1 is only preserved as a folded biotite foliation in intrafolial folds related to the second deformation phase (D2) (Fig. 4a and b). This second deformation event is the most pervasive and was responsible for development of a regional foliation under upper amphibolite facies conditions (S2) (Fig. 7). Phase D3 is represented by overturned to recumbent, close to open folds that only locally
Conclusion
The main foliation in the Sertânia Complex was developed under estimated metamorphic temperatures of 650–700 °C, resulting in common migmatization. It is associated with a W-trending stretching lineation and kinematic indicators showing top-to-the-W tectonic transport. Our data do not allow establishing exactly the age of metamorphism, but it is certainly related to the Brasiliano Orogeny since the main foliation is shared by Paleoproterozoic orthogneiss and Neoproterozoic paragneiss, in which
Acknowledgements
This work was supported through funding from the Brazilian agency Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq; grant 472582/2011-9). We thank Adejardo da Silva Filho, Andres Bustamante and undergraduate students for their participation in field work; CPRM – Geological Survey of Brazil for making available aerogeophysical images; and Roberto Weinberg, an anonymous reviewer and associate editor Natasha Wodicka for constructive comments that helped to improve the paper.
References (93)
- et al.
The Saharan metacraton
J. Afr. Earth Sc.
(2002) - et al.
The intraplate character of supercontinent tectonics
Gondwana Res.
(2013) - et al.
Upper mantle anisotropy of the Borborema Province, NE Brazil: implications for intra-plate deformation and sub-cratonic asthenospheric flow
Tectonophysics
(2015) - et al.
Orogenic development of the Adrar des Iforas (Tuareg Shield, NE Mali): geochemical and geochronological data and geodynamic implications
J. Geodyn.
(2016) Terrane assembly and geodynamic evolution of central-western Hoggar: a synthesis
J. Afr. Earth Sc.
(2003)- et al.
Shear zone-related folds
J. Struct. Geol.
(2005) - et al.
Structure and development of an anastomosing network of ductile shear zones
J. Struct. Geol.
(2010) - et al.
Linking accretionary orogenesis with supercontinent assembly
Earth Sci. Rev.
(2007) Active intracontinental transpressional mountain building in the Mongolian Altai: defining a new class of orogen
Earth Planet. Sci. Lett.
(2005)- et al.
Crustal growth in the 3.4 to 2.7 Ga São José de Campestre Massif, Borborema Province, NE Brazil
Precambr. Res.
(2013)
Distant effects of India-Eurasia convergence and Mesozoic intracontinental deformation in Central Asia: constraints from apatite fission-track thermochronology
J. Asian Earth Sci.
Isotopic and geochemical evidence of Proterozoic episodic crustal reworking within the Irumide belt of south-central Africa, the southern metacratonic boundary of an Archaean Bangweule Craton
Precambr. Res.
Intraplate mountain building in response to continent-continent colision – the Ancestral Rocky Mountains (North America) and inferences from the Tien Shan (Central Asia)
Tectonophysics
Late Paleoproterozoic terrane accretion in northwestern Canada and the case for circum-Columbian orogenesis
Precambr. Res.
U-Pb zircon ages of orthogneisses and supracrustal rocks of the Cariris Velhos belt: onset of Neoproterozoic rifting in the Borborema Province, NE Brazil
Precambr. Res.
Tonian granitic magmatism of the Borborema Province, NE Brazil: a review
J. S. Am. Earth Sci.
Intraplate deformation in central Australia, the link between subsidence and fault reactivation
Tectonophysics
Folding in high-grade rocks due to back-rotation between shear zones
J. Struct. Geol.
Tectonics of the North African Variscides (Morocco, western Algeria): an outline
C. R. Geosci.
The burning heart — the Proterozoic geology and geological evolution of the west Musgrave Region, central Australia
Gondwana Res.
Late Cryogenian-Ediacaran history of the Arabian-Nubian Shield: a review of depositional, plutonic, structural, and tectonic events in the closing stages of the northern East African Orogen
J. Afr. Earth Sc.
The accretionary Svecofennian orogen—insight from the BABEL profiles
Precambr. Res.
Age of detrital zircon and titanite in the Meguma Group, Southern Nova Scotia, Canada: clue to the origin of the Meguma Terrain
Tectonophysics
Two plates — many subduction zones: the Variscan orogeny reconsidered
Gondwana Res.
Floresta and Bodocó Mafic-Ultramafic Complexes, western Borborema Province, Brazil: geochemical and isotope constraints for evolution of a Neoproterozoic arc environment and retro-eclogitic hosted Ti-mineralization
Precambr. Res.
Metacraton: nature, genesis and behavior
Gondwana Res.
Constrains from zircon geochronology on the tectonic evolution of the Borborema Province: widespread intracontinental Neoproterozoic reworking of a Paleoproterozoic accretionary orogen
J. S. Am. Earth Sci.
Geochemistry of orthogneisses and metasedimentary rocks across a proposed terrane boundary in the Central Domain of Borborema Province, NE Brazil: geodynamic implications
J. S. Am. Earth Sci.
Oblique lineations in orthogneisses and supracrustal rocks: vertical partitioning of strain in a hot crust (Borborema Province, NE Brazil)
J. Struct. Geol.
Timing of crust formation, deposition of supracrustal sequences, and Transamazonian and Brasiliano metamorphism in the East Pernambuco belt (Borborema Province, NE Brazil): implications for western Gondwana assembly
Precambr. Res.
The age distributions of detrital zircons in metasedimentary sequences in eastern Borborema Province (NE Brazil): evidence for intracontinental sedimentation and orogenesis?
Precambr. Res.
Geochronological, thermochronological and thermobarometric constraints on deformation, magmatism and thermal regimes in eastern Borborema Province (NE Brazil)
J. S. Am. Earth Sci.
Paleoproterozoic accretionary and collisional processes and the built-up of the Borborema Province (NE Brazil): geochronological and geochemical evidence from the Central Domain
J. S. Am. Earth Sci.
From extension to shortening: dating the onset of the Brasiliano Orogeny in eastern Borborema Province (NE Brazil)
J. S. Am. Earth Sci.
The transition zone between the Pernambuco-Alagoas Domain and the Sergipano Belt (Borborema Province, NE Brazil): geochronological constraints on the ages of deposition, tectonic setting and metamorphism of metasedimentary rocks
J. S. Am. Earth Sci.
Deep magnetotelluric signatures of the early Neoproterozoic Cariris Velhos tectonic event within the Transversal sub-province of the Borborema Province, NE Brazil
Precambr. Res.
Arabian Shield magmatic cycles and their relationship with Gondwana assembly: insights from zircon U-Pb and Hf isotopes
Earth Planet. Sci. Lett.
Zircon trace element geochemistry: partitioning with garnet and the link between U-Pb ages and metamorphism
Chem. Geol.
Geochemistry and geochronology of pre-Brasiliano rocks from the Transversal Zone, Borborema Province, Northeast Brazil
J. S. Am. Earth Sci.
Early to late Paleoproterozoic magmatism in NE Brazil: The Alto Moxotó Terrane and its tectonic implications for the pre-West Gondwana assembly
J. S. Am. Earth Sci.
U/Pb and Sm/Nd geochronologic studies of the eastern Borborema Province, northeastern Brazil: Initial conclusions
J. S. Am. Earth Sci.
The Seridó Group of NE Brazil, a late Neoproterozoic pre- to syn-collisional basin in West Gondwana: insights from SHRIMP U-Pb detrital zircon ages and Sm-Nd crustal residence (TDM) ages
Precambr. Res.
Precambrian history of the Zona Transversal of the Borborema Province, NE Brazil: insights from Sm-Nd and U-Pb geochronology
J. S. Am. Earth Sci.
Early Ordovician metabasites from the Spanish Central System: a remnant of intraplate HP rocks in the Central Iberian Zone
Gondwana Res.
The Altaids of Central Asia: a tectonic and evolutionary innovative review
Earth Sci. Rev.
Accretionary orogenesis of the Chinese Altai: insights from Paleozoic granitoids
Chem. Geol.
Cited by (31)
Exploring the orogenic nature of the Cariris Velhos event (ca. 1000-920 Ma) of the Borborema Province (NE Brazil)
2024, Journal of South American Earth SciencesCrustal architecture of Neoproterozoic terrains of western Gondwana revealed by integrated geophysical and structural data on the eastern Borborema Province, NE Brazil
2023, Journal of South American Earth SciencesA review of the geophysical knowledge of the Borborema Province, NE-Brazil, and tectonic implications
2023, Journal of South American Earth SciencesA complex history of extension, subduction and collision in west Gondwana: Clues from the Riacho do Pontal orogen, Borborema Province (NE Brazil)
2023, Journal of South American Earth SciencesArrested tectonic development: Preservation of high-temperature fabrics in the sinistral Caiçara shear zone (Borborema province, northeastern Brazil)
2023, Journal of South American Earth Sciences