Integration of elemental and isotope data supports a Neoproterozoic Adamastor Ocean realm

Almeida, F.F.M., Hasui, Y., Brito Neves, B.B., Fuck, R.A. (1981) Brazilian structural provinces: an introduction. Earth-Science Reviews 17, 1–29.
Show in context

A large part of the orogen remained in South America as the 3,000 km long and 100–500 km wide Mantiqueira Province (Almeida et al., 1981) (Fig. 1a).
View in article

Amaral, L., Caxito, F.A., Pedrosa-Soares, A.C., Queiroga, G., Babinski, M., Trindade, R., Lana, C., Chemale, F. (2020) The Ribeirão da Folha ophiolite-bearing accretionary wedge (Araçuaí orogen, SE Brazil): new data for Cryogenian plagiogranite and metasedimentary rocks. Precambrian Research 336, 105522.
Show in context

Accretionary mélanges of the northern province (Fig. 1a) include MORB chemistry metabasalt, banded metadolerite, metagabbro and meta-ultramafic rocks, with εNd_(t) up to + 6.3 (Pedrosa-Soares et al., 1998; Amaral et al., 2020).
View in article
Rootless plagiogranite veins hosted by a banded metadolerite are dated at 645 ± 10 Ma (Amaral et al., 2020).
View in article

Araújo, C., Pedrosa-Soares, A., Lana, C., Tedeschi, M., Dussin, I. (2020) Primeiro registro de magmatismo juvenil no arco magmático Rio Doce, Orógeno Araçuaí meridional. In: XVII Simpósio Nacional de Estudos Tectônicos (SNET), SBG, Bento Gonçalves, Annals, 105.
Show in context

The Rio Doce plutonic and volcanic rocks show εNd_(t) of −2.9 to −13.6 with T_DMNd of 1,190–2,030 Ma, ⁸⁷Sr/⁸⁶Sr of 0.7059–0.7165 and zircon εHf_(t) of +2.3 to −11.7 (Tedeschi et al., 2016; Degler et al., 2017; Novo et al., 2018; Araújo et al., 2020; Corrales et al., 2020).
View in article

Arena, K.R., Hartmann, L.A., Lana, C. (2017) Tonian emplacement of ophiolites in the southern Brasiliano Orogen delimited by U-Pb-Hf isotopes of zircon from metasomatites. Gondwana Research 49, 296–332.
Show in context

The 715–920 Ma MORB chemistry mafic-ultramafic assemblages in the southern sector have zircon εHf_(t) up to +15 and mantle-like trace element signatures (Arena et al., 2017, 2018; Hartmann et al., 2019).
View in article

Arena, K.R., Hartmann, L.A., Lana, C. (2018) U–Pb–Hf isotopes and trace elements of metasomatic zircon delimit the evolution of neoproterozoic Capané ophiolite in the southern Brasiliano Orogen. International Geology Review 60, 911–928.
Show in context

The 715–920 Ma MORB chemistry mafic-ultramafic assemblages in the southern sector have zircon εHf_(t) up to +15 and mantle-like trace element signatures (Arena et al., 2017, 2018; Hartmann et al., 2019).
View in article

Aslanian, D., Moulin, M., Olivet, J. L., Unternehr, P., Matias, L., Bache, F., Rabineau, M., Nouzé, H., Klingelheofer, F., Contrucci, I., Labails, C. (2009) Brazilian and African passive margins of the Central Segment of the South Atlantic Ocean: Kinematic constraints. Tectonophysics 468, 98–112.
Show in context

However, those estimates are contingent and cannot be used as hard proof against mobilistic models, because: 1) the ocean was probably fragmented in smaller sub-domains such as in the present day western Pacific and also connected to a much large Neoproterozoic oceanic system (Cordani et al., 2003) (Fig. 1b); 2) the Neoproterozoic upper mantle was warmer, leading to distinct spreading and subduction rates and dynamics (Brown, 2014); 3) intense wrench tectonics with thousands-of-km long shear zones obliterated former low angle surfaces and displaced allochthonous units far from their original position; 4) age, size and time span of an ocean have little significance in determining whether subduction is feasible or not (Hall, 2019), while lithospheric weaknesses such as magma-rich rift systems present in the orogen precursor basins (Tack et al., 2001; Basei et al., 2008) might play a major role in subduction initiation (Stern and Gerya, 2018); 5) those calculations use a palinspastic incorrect pre-drift reconstruction, ignoring at least ca. 280 km of restored continental crust now stretched in the Brazilian and African passive margins (Aslanian et al., 2009); 6) the termination of the orogen in a gulf partially enclosed by continental crust implies much lower convergence rates; and 7) non-Euclidean geometry implies the diachronous along strike opening and closure of oceanic basins.
View in article

Babinski, M., Chemale, F., Hartmann, L.A., Van Schmus, W.R., Silva, L.C. (1996) Juvenile accretion at 750–700 Ma in southern Brazil. Geology 24, 439–442.
Show in context

The São Gabriel terrane in the southern region (Fig. 1a) yielded U-Pb zircon ages of 800–860 Ma and 680–770 Ma (Babinski et al., 1996; Saalmann et al., 2005).
View in article
Sm-Nd T_DM are at 800–1,000 Ma with εNd_(t) on the depleted mantle curve (up to +8, Babinski et al., 1996; Saalmann et al., 2005) and zircon εHf_(t) from +14 to +8 (Cerva-Alves et al., 2020).
View in article

Babinski, M., Chemale, F., Van Schmus, W.R., Hartmann, L.A., Silva, L.C. (1997) U-Pb and Sm-Nd geochronology of the neoproterozoic granitic-gneissic Dom Feliciano Belt, southern Brazil. Journal of South American Earth Sciences 10, 263–274.
Show in context

The Pelotas-Florianópolis-Aiguá batholith forms a multi-intrusion geological structure consisting of granite, gabbro and diorite with ⁸⁷Sr/⁸⁶Sr_i ratios of ca. 0.712, εNd of −3.6 to −22.2 and T_DMNd of 1,200–2,400 Ma (Babinski et al., 1997; Koester et al., 2016).
View in article

Basei, M.A.S., Frimmel, H.E., Nutman, A.P., Preciozzi, F. (2008) West Gondwana amalgamation based on detrital zircon ages from Neoproterozoic Ribeira and Dom Feliciano belts of South America and comparison with coeval sequences from SW Africa. Geological Society, London, Special Publications 294, 239–256.
Show in context

However, those estimates are contingent and cannot be used as hard proof against mobilistic models, because: 1) the ocean was probably fragmented in smaller sub-domains such as in the present day western Pacific and also connected to a much large Neoproterozoic oceanic system (Cordani et al., 2003) (Fig. 1b); 2) the Neoproterozoic upper mantle was warmer, leading to distinct spreading and subduction rates and dynamics (Brown, 2014); 3) intense wrench tectonics with thousands-of-km long shear zones obliterated former low angle surfaces and displaced allochthonous units far from their original position; 4) age, size and time span of an ocean have little significance in determining whether subduction is feasible or not (Hall, 2019), while lithospheric weaknesses such as magma-rich rift systems present in the orogen precursor basins (Tack et al., 2001; Basei et al., 2008) might play a major role in subduction initiation (Stern and Gerya, 2018); 5) those calculations use a palinspastic incorrect pre-drift reconstruction, ignoring at least ca. 280 km of restored continental crust now stretched in the Brazilian and African passive margins (Aslanian et al., 2009); 6) the termination of the orogen in a gulf partially enclosed by continental crust implies much lower convergence rates; and 7) non-Euclidean geometry implies the diachronous along strike opening and closure of oceanic basins.
View in article

Basei, M.A.S., Frimmel, H.E., Campos Neto, M.C., Ganade de Araújo, C.E., Castro, N.A., Passarelli, C.R. (2018) The tectonic history of the southern Adamastor Ocean based on a correlation of the Kaoko and Dom Feliciano belts. In: Siegesmund S., Basei M., Oyhantçabal P., Oriolo S. (Eds.) Geology of Southwest Gondwana. Regional Geology Reviews. Springer, Cham., 63–85.
Show in context

Widespread Ediacaran (mainly ca. 580–630 Ma) magmatic rocks represent an expanded series of medium to high K calc-alkaline, magnesian, metaluminous, I-type tonalites to granodiorites rich in dioritic to mafic enclaves, with minor gabbro (Fig. 1a) (Tedeschi et al., 2016; Basei et al., 2018; Corrales et al., 2020).
View in article
The original proposition of Hartnady et al. (1985) would correspond to the Marmora back-arc basin in the African counterparts, east of the Pelotas arc (Frimmel et al., 2011; Basei et al., 2018).
View in article

Brown, M. (2014) The contribution of metamorphic petrology to understanding lithosphere evolution and geodynamics. Geoscience Frontiers 5, 553–569.
Show in context

However, those estimates are contingent and cannot be used as hard proof against mobilistic models, because: 1) the ocean was probably fragmented in smaller sub-domains such as in the present day western Pacific and also connected to a much large Neoproterozoic oceanic system (Cordani et al., 2003) (Fig. 1b); 2) the Neoproterozoic upper mantle was warmer, leading to distinct spreading and subduction rates and dynamics (Brown, 2014); 3) intense wrench tectonics with thousands-of-km long shear zones obliterated former low angle surfaces and displaced allochthonous units far from their original position; 4) age, size and time span of an ocean have little significance in determining whether subduction is feasible or not (Hall, 2019), while lithospheric weaknesses such as magma-rich rift systems present in the orogen precursor basins (Tack et al., 2001; Basei et al., 2008) might play a major role in subduction initiation (Stern and Gerya, 2018); 5) those calculations use a palinspastic incorrect pre-drift reconstruction, ignoring at least ca. 280 km of restored continental crust now stretched in the Brazilian and African passive margins (Aslanian et al., 2009); 6) the termination of the orogen in a gulf partially enclosed by continental crust implies much lower convergence rates; and 7) non-Euclidean geometry implies the diachronous along strike opening and closure of oceanic basins.
View in article

Cavalcante, C., Fossen, H., Almeida, R P., Hollanda, M.H.B., Egydio-Silva, M. (2019) Reviewing the puzzling intracontinental termination of the Araçuaí-West Congo orogenic belt and its implications for orogenic development. Precambrian Research 322, 85–98.
Show in context

Early postulations of tectonic evolution of the Mantiqueira Province emphasised intra-continental models (e.g., Torquato and Cordani, 1981; Porada et al., 1989), an interpretation that received renewed attention in recent years (Cavalcante et al., 2019; Meira et al., 2019; Fossen et al., 2020; Konopásek et al., 2020).
View in article

Cerva-Alves, T., Hartmann, L.A., Remus, M.V.D., Lana, C. (2020) Integrated ophiolite and arc evolution, southern Brasiliano Orogen. Precambrian Research 341, 105648.
Show in context

Sm-Nd T_DM are at 800–1,000 Ma with εNd_(t) on the depleted mantle curve (up to +8, Babinski et al., 1996; Saalmann et al., 2005) and zircon εHf_(t) from +14 to +8 (Cerva-Alves et al., 2020).
View in article

Cordani, U.G., Brito Neves, B.B., D’Agrella-Filho, M.S. (2003) From Rodinia to Gondwana: a review of the available evidence from South America. Gondwana Research 6, 275–283.
Show in context

The Cretaceous breakup of Gondwana in the South Atlantic region produced an asymmetric division of the Neoproterozoic Brasiliano/Pan-African Orogen (Fig. 1a,b) (Cordani et al., 2003).
View in article
However, those estimates are contingent and cannot be used as hard proof against mobilistic models, because: 1) the ocean was probably fragmented in smaller sub-domains such as in the present day western Pacific and also connected to a much large Neoproterozoic oceanic system (Cordani et al., 2003) (Fig. 1b); 2) the Neoproterozoic upper mantle was warmer, leading to distinct spreading and subduction rates and dynamics (Brown, 2014); 3) intense wrench tectonics with thousands-of-km long shear zones obliterated former low angle surfaces and displaced allochthonous units far from their original position; 4) age, size and time span of an ocean have little significance in determining whether subduction is feasible or not (Hall, 2019), while lithospheric weaknesses such as magma-rich rift systems present in the orogen precursor basins (Tack et al., 2001; Basei et al., 2008) might play a major role in subduction initiation (Stern and Gerya, 2018); 5) those calculations use a palinspastic incorrect pre-drift reconstruction, ignoring at least ca. 280 km of restored continental crust now stretched in the Brazilian and African passive margins (Aslanian et al., 2009); 6) the termination of the orogen in a gulf partially enclosed by continental crust implies much lower convergence rates; and 7) non-Euclidean geometry implies the diachronous along strike opening and closure of oceanic basins.
View in article

Corrales, F.F., Dussin, I.A., Heilbron, M., Bruno, H., Bersan, S., Valeriano, C.M., Pedrosa-Soares, A.C., Tedeschi, M. (2020) Coeval high Ba-Sr arc-related and OIB Neoproterozoic rocks linking pre-collisional magmatism of the Ribeira and Araçuaí orogenic belts, SE-Brazil. Precambrian Research 337, 105476.
Show in context

Widespread Ediacaran (mainly ca. 580–630 Ma) magmatic rocks represent an expanded series of medium to high K calc-alkaline, magnesian, metaluminous, I-type tonalites to granodiorites rich in dioritic to mafic enclaves, with minor gabbro (Fig. 1a) (Tedeschi et al., 2016; Basei et al., 2018; Corrales et al., 2020).
View in article
The Rio Doce plutonic and volcanic rocks show εNd_(t) of −2.9 to −13.6 with T_DMNd of 1,190–2,030 Ma, ⁸⁷Sr/⁸⁶Sr of 0.7059–0.7165 and zircon εHf_(t) of +2.3 to −11.7 (Tedeschi et al., 2016; Degler et al., 2017; Novo et al., 2018; Araújo et al., 2020; Corrales et al., 2020).
View in article

Degler, R., Pedrosa-Soares, A., Dussin, I., Queiroga, G., Schulz, B. (2017) Contrasting provenance and timing of metamorphism from paragneisses of the Araçuaí-Ribeira orogenic system, Brazil: Hints for Western Gondwana assembly. Gondwana Research 51, 30–50.
Show in context

The Rio Doce plutonic and volcanic rocks show εNd_(t) of −2.9 to −13.6 with T_DMNd of 1,190–2,030 Ma, ⁸⁷Sr/⁸⁶Sr of 0.7059–0.7165 and zircon εHf_(t) of +2.3 to −11.7 (Tedeschi et al., 2016; Degler et al., 2017; Novo et al., 2018; Araújo et al., 2020; Corrales et al., 2020).
View in article

Fossen, H., Cavalcante, C., Konopásek, J., Meira, V.T., Almeida, R.P., Hollanda, M.H.B., Trompette, R. (2020) A critical discussion of the subduction-collision model for the Neoproterozoic Araçuaí-West Congo orogen. Precambrian Research 343, 105715.
Show in context

Early postulations of tectonic evolution of the Mantiqueira Province emphasised intra-continental models (e.g., Torquato and Cordani, 1981; Porada et al., 1989), an interpretation that received renewed attention in recent years (Cavalcante et al., 2019; Meira et al., 2019; Fossen et al., 2020; Konopásek et al., 2020).
View in article
Recently revisited models of intracontinental orogeny focused on a “space problem” for the development of an Adamastor oceanic realm based on estimates of maximum oceanic width using modern spreading and subduction rates (Fossen et al., 2020; Konopásek et al., 2020).
View in article

Frimmel, H.E., Basei, M.S., Gaucher, C. (2011) Neoproterozoic geodynamic evolution of SW-Gondwana: a southern African perspective. International Journal of Earth Sciences 100, 323–354.
Show in context

The original proposition of Hartnady et al. (1985) would correspond to the Marmora back-arc basin in the African counterparts, east of the Pelotas arc (Frimmel et al., 2011; Basei et al., 2018).
View in article

Hall, R. (2019) The subduction initiation stage of the Wilson cycle. Geological Society, London, Special Publications 470, 415–437.
Show in context

However, those estimates are contingent and cannot be used as hard proof against mobilistic models, because: 1) the ocean was probably fragmented in smaller sub-domains such as in the present day western Pacific and also connected to a much large Neoproterozoic oceanic system (Cordani et al., 2003) (Fig. 1b); 2) the Neoproterozoic upper mantle was warmer, leading to distinct spreading and subduction rates and dynamics (Brown, 2014); 3) intense wrench tectonics with thousands-of-km long shear zones obliterated former low angle surfaces and displaced allochthonous units far from their original position; 4) age, size and time span of an ocean have little significance in determining whether subduction is feasible or not (Hall, 2019), while lithospheric weaknesses such as magma-rich rift systems present in the orogen precursor basins (Tack et al., 2001; Basei et al., 2008) might play a major role in subduction initiation (Stern and Gerya, 2018); 5) those calculations use a palinspastic incorrect pre-drift reconstruction, ignoring at least ca. 280 km of restored continental crust now stretched in the Brazilian and African passive margins (Aslanian et al., 2009); 6) the termination of the orogen in a gulf partially enclosed by continental crust implies much lower convergence rates; and 7) non-Euclidean geometry implies the diachronous along strike opening and closure of oceanic basins.
View in article

Hartmann, L.A., Werle, M., Michelin, C.R.L., Lana, C., Queiroga, G., Castro, M.P., Arena, K.R. (2019) Proto-Adamastor ocean crust (920 Ma) described in Brasiliano Orogen from coetaneous zircon and tourmaline. Geoscience Frontiers 10, 1623–1633.
Show in context

The 715–920 Ma MORB chemistry mafic-ultramafic assemblages in the southern sector have zircon εHf_(t) up to +15 and mantle-like trace element signatures (Arena et al., 2017, 2018; Hartmann et al., 2019).
View in article
Dravite in altered oceanic crust has typical ocean floor δ¹¹B up to +1.8 (Hartmann et al., 2019).
View in article

Hartnady, C., Joubert, P., Stowe, C. (1985) Proterozoic crustal evolution in southwestern Africa. Episodes 8, 236–244.
Show in context

However, a wealth of field, geochemical and geochronological data produced in recent decades progressively prompted interpretations involving distinct stages of typical Wilson cycle processes involved in the closure of the Adamastor Ocean (originally defined by Hartnady et al., 1985).
View in article
The original proposition of Hartnady et al. (1985) would correspond to the Marmora back-arc basin in the African counterparts, east of the Pelotas arc (Frimmel et al., 2011; Basei et al., 2018).
View in article

Heilbron, M., Valeriano, C.M., Peixoto, C., Tupinambá, M., Neubauer, F., Dussin, I., Corrales, F., Bruno, H., Lobato, M., Almeida, J.C.H., Silva, L.G.E. (2020) Neoproterozoic magmatic arc systems of the central Ribeira belt, SE-Brazil, in the context of the West-Gondwana pre-collisional history: A review. Journal of South American Earth Sciences, 102710.
Show in context

The 835–860 Ma Serra da Prata Complex of the central province has whole rock εNd_(t) from +6.4 to +0.9 with T_DM Nd of 860–1,200 Ma, ⁸⁷Sr/⁸⁶Sr_i < 0.7035, zircon εHf_(t) from +14 to +10, and T_DM Hf of 840–1,010 Ma (Peixoto et al., 2017; Heilbron et al., 2020; Santiago et al., 2020).
View in article

Koester, E., Porcher, C. C., Pimentel, M. M., Fernandes, L.A.D., Vignol-Lelarge, M.L., Oliveira, L.D., Ramos, R.C. (2016) Further evidence of 777 Ma subduction-related continental arc magmatism in Eastern Dom Feliciano Belt, southern Brazil: the Chácara das Pedras Orthogneiss. Journal of South American Earth Sciences 68, 155–166.
Show in context

The Pelotas-Florianópolis-Aiguá batholith forms a multi-intrusion geological structure consisting of granite, gabbro and diorite with ⁸⁷Sr/⁸⁶Sr_i ratios of ca. 0.712, εNd of −3.6 to −22.2 and T_DMNd of 1,200–2,400 Ma (Babinski et al., 1997; Koester et al., 2016).
View in article

Konopásek, J., Cavalcante, C., Fossen, H., Janoušek, V. (2020) Adamastor–an ocean that never existed?. Earth-Science Reviews 205, 103201.
Show in context

Early postulations of tectonic evolution of the Mantiqueira Province emphasised intra-continental models (e.g., Torquato and Cordani, 1981; Porada et al., 1989), an interpretation that received renewed attention in recent years (Cavalcante et al., 2019; Meira et al., 2019; Fossen et al., 2020; Konopásek et al., 2020).
View in article
Recently revisited models of intracontinental orogeny focused on a “space problem” for the development of an Adamastor oceanic realm based on estimates of maximum oceanic width using modern spreading and subduction rates (Fossen et al., 2020; Konopásek et al., 2020).
View in article

Meira, V.T., Garcia‐Casco, A., Hyppolito, T., Juliani, C., Schorscher, J.H.D. (2019) Tectono‐Metamorphic Evolution of the Central Ribeira Belt, Brazil: A Case of Late Neoproterozoic Intracontinental Orogeny and Flow of Partially Molten Deep Crust During the Assembly of West Gondwana. Tectonics 38, 3182–3209.
Show in context

Early postulations of tectonic evolution of the Mantiqueira Province emphasised intra-continental models (e.g., Torquato and Cordani, 1981; Porada et al., 1989), an interpretation that received renewed attention in recent years (Cavalcante et al., 2019; Meira et al., 2019; Fossen et al., 2020; Konopásek et al., 2020).
View in article

Novo, T.A., Pedrosa-Soares, A., Vieira, V.S., Dussin, I., Silva, L.C. (2018) The Rio Doce Group revisited: an Ediacaran arc-related volcano-sedimentary basin, Araçuaí orogen (SE Brazil). Journal of South American Earth Sciences 85, 345–361.
Show in context

The Rio Doce plutonic and volcanic rocks show εNd_(t) of −2.9 to −13.6 with T_DMNd of 1,190–2,030 Ma, ⁸⁷Sr/⁸⁶Sr of 0.7059–0.7165 and zircon εHf_(t) of +2.3 to −11.7 (Tedeschi et al., 2016; Degler et al., 2017; Novo et al., 2018; Araújo et al., 2020; Corrales et al., 2020).
View in article

Passarelli, C.R., Basei, M.A.S., Siga Jr., O., Harara, O.M.M. (2018) The Luis Alves and Curitiba terranes: continental fragments in the Adamastor Ocean. In: Siegesmund S., Basei M., Oyhantçabal P., Oriolo S. (Eds) Geology of Southwest Gondwana. Regional Geology Reviews. Springer, Cham., 189–215.
Show in context

Mafic-ultramafic rock associations in the central sector include dunite cumulates, MORB- and IAT-like gabbro, metabasic rocks with sheeted dikes, pillow lavas and chert, emplaced at ca. 630 Ma (Tassinari et al., 2001; Passarelli et al., 2018).
View in article

Pedrosa-Soares, A., Vidal, P., Leonardos, O.H., Brito Neves, B.B. (1998) Neoproterozoic oceanic remnants in eastern Brazil: further evidence and refutation of an exclusively ensialic evolution for the Araçuaí–West Congo orogen. Geology 26, 519–522.
Show in context

Accretionary mélanges of the northern province (Fig. 1a) include MORB chemistry metabasalt, banded metadolerite, metagabbro and meta-ultramafic rocks, with εNd_(t) up to + 6.3 (Pedrosa-Soares et al., 1998; Amaral et al., 2020).
View in article

Peel, E., Sanchez-Bettucci, L., Basei, M.A.S. (2018) Geology and geochronology of Paso del Dragón Complex (northeastern Uruguay): Implications on the evolution of the Dom Feliciano Belt (Western Gondwana). Journal of South American Earth Sciences 85, 250–262.
Show in context

The southernmost ophiolites show whole rock εNd_(t) up to +8.5 (Peel et al., 2018; Ramos et al., 2020) (Fig. 1a).
View in article

Peixoto, C.A., Heilbron, M., Ragatky, D., Armstrong, R., Dantas, E., Valeriano, C.M., Simonetti, A. (2017) Tectonic evolution of the Juvenile Tonian Serra da Prata magmatic arc in the Ribeira belt, SE Brazil: Implications for early west Gondwana amalgamation. Precambrian Research 302, 221–254.
Show in context

The 835–860 Ma Serra da Prata Complex of the central province has whole rock εNd_(t) from +6.4 to +0.9 with T_DM Nd of 860–1,200 Ma, ⁸⁷Sr/⁸⁶Sr_i < 0.7035, zircon εHf_(t) from +14 to +10, and T_DM Hf of 840–1,010 Ma (Peixoto et al., 2017; Heilbron et al., 2020; Santiago et al., 2020).
View in article

Porada, H. (1989) Pan-African rifting and orogenesis in southern to equatorial Africa and eastern Brazil. Precambrian Research 44, 103–136.
Show in context

Early postulations of tectonic evolution of the Mantiqueira Province emphasised intra-continental models (e.g., Torquato and Cordani, 1981; Porada et al., 1989), an interpretation that received renewed attention in recent years (Cavalcante et al., 2019; Meira et al., 2019; Fossen et al., 2020; Konopásek et al., 2020).
View in article

Ramos, R.C., Koester, E., Vieira, D.T. (2020) Sm–Nd systematics of metaultramafic-mafic rocks from the Arroio Grande Ophiolite (Brazil): Insights on the evolution of the South Adamastor paleo-ocean. Geoscience Frontiers, doi: 10.1016/j.gsf.2020.02.013.
Show in context

The southernmost ophiolites show whole rock εNd_(t) up to +8.5 (Peel et al., 2018; Ramos et al., 2020) (Fig. 1a).
View in article

Raimondo, T., Hand, M., Collins, W.J. (2014) Compressional intracontinental orogens: Ancient and modern perspectives. Earth-Science Reviews 130, 128–153.
Show in context

The archetypical examples of intracontinental orogens (Raimondo et al., 2014), as proposed in the last century and recently revived, lack many of the tectonic components recognised in the last decades in the Mantiqueira Province.
View in article

Ricardo, B.S., Faleiros, F.M., Moraes, R., Siga Jr., O., Campanha, G.A. (2020) Tectonic implications of juxtaposed high-and low-pressure metamorphic field gradient rocks in the Turvo-Cajati Formation, Curitiba Terrane, Ribeira Belt, Brazil. Precambrian Research, 105766.
Show in context

The evidence provided here suggests that the main ocean was located to the west of the arc rocks, where recently paired HP-HT metamorphic belts were described (Ricardo et al., 2020).
View in article

Saalmann, K., Hartmann, L.A., Remus, M.V.D., Koester, E., Conceição, R.V. (2005) Sm–Nd isotope geochemistry of metamorphic volcano-sedimentary successions in the São Gabriel Block, southernmost Brazil: evidence for the existence of juvenile Neoproterozoic oceanic crust to the east of the Rio de la Plata craton. Precambrian Research 136, 159–175.
Show in context

The São Gabriel terrane in the southern region (Fig. 1a) yielded U-Pb zircon ages of 800–860 Ma and 680–770 Ma (Babinski et al., 1996; Saalmann et al., 2005).
View in article
Sm-Nd T_DM are at 800–1,000 Ma with εNd_(t) on the depleted mantle curve (up to +8, Babinski et al., 1996; Saalmann et al., 2005) and zircon εHf_(t) from +14 to +8 (Cerva-Alves et al., 2020).
View in article

Santiago, R., Caxito, F.A., Pedrosa-Soares, A., Neves, M., Dantas, E. (2020) Tonian island arc remnants in the northern Ribeira orogeny of western Gondwana: The Caxixe batholith (Espírito Santo state, SE Brazil). Precambrian Research 351, 105944.
Show in context

The 835–860 Ma Serra da Prata Complex of the central province has whole rock εNd_(t) from +6.4 to +0.9 with T_DM Nd of 860–1,200 Ma, ⁸⁷Sr/⁸⁶Sr_i < 0.7035, zircon εHf_(t) from +14 to +10, and T_DM Hf of 840–1,010 Ma (Peixoto et al., 2017; Heilbron et al., 2020; Santiago et al., 2020).
View in article

Stern, R.J., Gerya, T. (2018) Subduction initiation in nature and models: A review. Tectonophysics 746, 173–198.
Show in context

However, those estimates are contingent and cannot be used as hard proof against mobilistic models, because: 1) the ocean was probably fragmented in smaller sub-domains such as in the present day western Pacific and also connected to a much large Neoproterozoic oceanic system (Cordani et al., 2003) (Fig. 1b); 2) the Neoproterozoic upper mantle was warmer, leading to distinct spreading and subduction rates and dynamics (Brown, 2014); 3) intense wrench tectonics with thousands-of-km long shear zones obliterated former low angle surfaces and displaced allochthonous units far from their original position; 4) age, size and time span of an ocean have little significance in determining whether subduction is feasible or not (Hall, 2019), while lithospheric weaknesses such as magma-rich rift systems present in the orogen precursor basins (Tack et al., 2001; Basei et al., 2008) might play a major role in subduction initiation (Stern and Gerya, 2018); 5) those calculations use a palinspastic incorrect pre-drift reconstruction, ignoring at least ca. 280 km of restored continental crust now stretched in the Brazilian and African passive margins (Aslanian et al., 2009); 6) the termination of the orogen in a gulf partially enclosed by continental crust implies much lower convergence rates; and 7) non-Euclidean geometry implies the diachronous along strike opening and closure of oceanic basins.
View in article

Tack, L., Wingate, M.T.D., Liégeois, J.P., Fernandez-Alonso, M., Deblond, A. (2001) Early Neoproterozoic magmatism (1000–910 Ma) of the Zadinian and Mayumbian Groups (Bas-Congo): onset of Rodinia rifting at the western edge of the Congo craton. Precambrian Research 110, 277–306.
Show in context

However, those estimates are contingent and cannot be used as hard proof against mobilistic models, because: 1) the ocean was probably fragmented in smaller sub-domains such as in the present day western Pacific and also connected to a much large Neoproterozoic oceanic system (Cordani et al., 2003) (Fig. 1b); 2) the Neoproterozoic upper mantle was warmer, leading to distinct spreading and subduction rates and dynamics (Brown, 2014); 3) intense wrench tectonics with thousands-of-km long shear zones obliterated former low angle surfaces and displaced allochthonous units far from their original position; 4) age, size and time span of an ocean have little significance in determining whether subduction is feasible or not (Hall, 2019), while lithospheric weaknesses such as magma-rich rift systems present in the orogen precursor basins (Tack et al., 2001; Basei et al., 2008) might play a major role in subduction initiation (Stern and Gerya, 2018); 5) those calculations use a palinspastic incorrect pre-drift reconstruction, ignoring at least ca. 280 km of restored continental crust now stretched in the Brazilian and African passive margins (Aslanian et al., 2009); 6) the termination of the orogen in a gulf partially enclosed by continental crust implies much lower convergence rates; and 7) non-Euclidean geometry implies the diachronous along strike opening and closure of oceanic basins.
View in article

Tassinari, C.C., Munhá, J.M., Ribeiro, A., Correia, C.T. (2001) Neoproterozoic oceans in the Ribeira Belt (southeastern Brazil): The Pirapora do Bom Jesus ophiolitic complex. Episodes, 24, 245–251.
Show in context

Mafic-ultramafic rock associations in the central sector include dunite cumulates, MORB- and IAT-like gabbro, metabasic rocks with sheeted dikes, pillow lavas and chert, emplaced at ca. 630 Ma (Tassinari et al., 2001; Passarelli et al., 2018).
View in article

Tedeschi, M., Pedrosa-Soares, A., Dussin, I., Tassinari, C., Silva, L.C., Gonçalves, L.E., Alkmim, L., Lana, C., Figueiredo, C., Dantas E., Medeiros, S., Campos, C., Corrales, F., Heilbron, M. (2016) The Ediacaran Rio Doce magmatic arc revisited (Araçuaí-Ribeira orogenic system, SE Brazil). Journal of South American Earth Sciences 68, 167–186.
Show in context

Widespread Ediacaran (mainly ca. 580–630 Ma) magmatic rocks represent an expanded series of medium to high K calc-alkaline, magnesian, metaluminous, I-type tonalites to granodiorites rich in dioritic to mafic enclaves, with minor gabbro (Fig. 1a) (Tedeschi et al., 2016; Basei et al., 2018; Corrales et al., 2020).
View in article
The Rio Doce plutonic and volcanic rocks show εNd_(t) of −2.9 to −13.6 with T_DMNd of 1,190–2,030 Ma, ⁸⁷Sr/⁸⁶Sr of 0.7059–0.7165 and zircon εHf_(t) of +2.3 to −11.7 (Tedeschi et al., 2016; Degler et al., 2017; Novo et al., 2018; Araújo et al., 2020; Corrales et al., 2020).
View in article

Torquato, J.R., Cordani, U.G. (1981) Brazil-Africa geological links. Earth-Science Reviews 17, 155–176.
Show in context

Early postulations of tectonic evolution of the Mantiqueira Province emphasised intra-continental models (e.g., Torquato and Cordani, 1981; Porada et al., 1989), an interpretation that received renewed attention in recent years (Cavalcante et al., 2019; Meira et al., 2019; Fossen et al., 2020; Konopásek et al., 2020).
View in article

Tupinambá, M., Heilbron, M., Valeriano, C., Porto Jr., R., Dios, F.B., Machado, N., Silva, L.G.E., Almeida, J.C.H. (2012) Juvenile contribution of the Neoproterozoic Rio Negro magmatic arc (Ribeira Belt, Brazil): implications for western Gondwana amalgamation. Gondwana Research 21, 422–438.
Show in context

The Rio Negro Complex comprises intermediate to felsic plutonic rocks (620–790 Ma) with εNd_(t) from +5 to −3 and ⁸⁷Sr/⁸⁶Sr < 0.705, as well as high K calc-alkaline to shoshonitic felsic rocks (605–620 Ma) with εNd_(t) = −3 to −14 and ⁸⁷Sr/⁸⁶Sr = 0.7050–0.7100 (Tupinambá et al., 2012).
View in article