G'day Gondwana - the final accretion of a supercontinent: U-Pb ages from the post-orogenic Sao Vicente Granite, northern Paraguay Belt, Brazil

The Paraguay Belt in central South America is part of a larger chain of orogenic belts, including the Araguaia Belt to the northeast and potentially the Pampean Belt to the south, which are believed to mark the suture zone of the Clymene Ocean - interpreted amongst the youngest of the Gondwana amalgamation orogens. The post-orogenic Sao Vicente Granite crops out in the northern Paraguay Belt and cuts the basal unit of the deformed and metamorphosed Cuiaba Group. The age of this granite therefore provides a long sort after minimum age for orogenesis within the belt. Dating crystallisation of this important intrusion is challenging due to the presence of considerable common-Pb. However, based on LA-ICPMS dating of more than 100 zircons from three separate samples we interpret a robust crystallisation age for the Sao Vicente batholith at 518 +/- 4 Ma. This age constrains the termination of deformation within the Paraguay Belt and the final accretion of the supercontinent Gondwana. (C) 2011 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved.

Geochronological constraints on the age of a Permo-Triassic impact event: U-Pb and Ar-40/Ar-39 results for the 40 km Araguainha structure of central Brazil

Impact cratering has been a fundamental geological process in Earth history with major ramifications for the biosphere. The complexity of shocked and melted rocks within impact structures presents difficulties for accurate and precise radiogenic isotope age determination, hampering the assessment of the effects of an individual event in the geological record. We demonstrate the utility of a multi-chronometer approach in our study of samples from the 40 km diameter Araguainha impact structure of central Brazil. Samples of uplifted basement granite display abundant evidence of shock deformation, but U/Pb ages of shocked zircons and the Ar-40/Ar-39 ages of feldspar from the granite largely preserve the igneous crystallization and cooling history. Mixed results are obtained from in situ Ar-40/Ar-39 spot analyses of shocked igneous biotites in the granite, with deformation along kink-bands resulting in highly localized, partial resetting in these grains. Likewise, spot analyses of perlitic glass from pseudotachylitic breccia samples reflect a combination of argon inheritance from wall rock material, the age of the glass itself, and post-impact devitrification. The timing of crater formation is better assessed using samples of impact-generated melt rock where isotopic resetting is associated with textural evidence of melting and in situ crystallization. Granular aggregates of neocrystallized zircon form a cluster of ten U-Pb ages that yield a "Concordia" age of 247.8 +/- 3.8 Ma. The possibility of Pb loss from this population suggests that this is a minimum age for the impact event. The best evidence for the age of the impact comes from the U-Th-Pb dating of neocrystallized monazite and Ar-40/Ar-39 step heating of three separate populations of post-impact, inclusion-rich quartz grains that are derived from the infill of miarolitic cavities. The Pb-206/U-238 age of 254.5 +/- 3.2 Ma (2 sigma error) and Pb-208/Th-232 age of 255.2 +/- 4.8 Ma (2 sigma error) of monazite, together with the inverse, 18 point isochron age of 254 +/- 10 Ma (MSWD = 0.52) for the inclusion-rich quartz grains yield a weighted mean age of 254.7 +/- 2.5 Ma (0.99%, 2 sigma error) for the impact event. The age of the Araguainha crater overlaps with the timing of the Permo-Triassic boundary, within error, but the calculated energy released by the Araguainha impact is insufficient to be a direct cause of the global mass extinction. However, the regional effects of the Araguainha impact event in the Parana-Karoo Basin may have been substantial. (C) 2012 Elsevier Ltd. All rights reserved.

U-Pb zircon ages of orthogneisses and supracrustal rocks of the Cariris Velhos belt: Onset of Neoproterozoic rifting in the Borborema Province, NE Brazil

New geochronological and geochemical constraints on Precambrian sedimentary and volcanic successions exposed in the western part of the Central Domain of the Borborema Province, NE Brazil, indicate the presence of two distinct tectono-stratigraphic complexes: Riacho Gravata and Sao Caetano. Both complexes and associated orthogneisses are referred in the literature as the Cariris Velhos belt, having depositional, extrusive, or intrusive ages within the interval 985-913 Ma. The Riacho Gravata complex consists of bimodal (but mostly felsic) volcanic and volcanoclastic rocks, muscovite+/-graphite schists, quartzites, and marble with local occurrences of banded-iron-formation. The Sao Caetano complex mainly consists of metagreywackes, marbles, calc-silicate rocks, and rare meta-mafic rocks. Meta-mafic rocks from both complexes have geochemical signatures similar to those of continental flood basalts, with epsilon Nd (1.0 Ga) values ranging from -1.0 to -2.8. Felsic volcanic rocks from the Riacho Gravata complex show epsilon Nd (1.0 Ga) values ranging from -1.0 to -7.4 and geochemical signatures similar to A(2)-type granitoids. New SHRIMP U-Pb zircon data from felsic volcanic rocks within the Riacho Gravata complex yielded ages of 1091 +/- 13 Ma and 996 +/- 13 Ma. In contrast, meta-graywackes from the Sao Caetano complex show a maximum deposition age of ca. 806 Ma in the northern part and ca. 862 Ma in the southern part of the outcrop area. The orthogneisses show epsilon Nd (1.0 Ga) values ranging from 1.0 to -4.2 with U/Pb TIMS and SHRIMP ages ranging from 960 to 926 Ma and geochemical signatures of A(2)-type granitoids. The data reported in this paper suggest at least two periods of extension within the Central Domain of the Borborema Province, the first starts ca. 1091 Ma with magmatism and deposition, creating the Riacho Gravata basin and continued intrusion of A-type granites to 920 Ma. A second rift event, which reactivated old faults, generated a basin with a maximum deposition age of ca. 806 Ma. Furthermore, the oldest granitoids cutting these metasedimentary rocks have crystallization ages of ca. 600 Ma. This suggests that the second rift event could be early Brasiliano in age. The resulting Sao Caetano basin received detritus from a variety of sources, although detritus from the Riacho Gravata complex dominated. Deposition ages of the Riacho Gravata and the Sao Caetano complexes are coeval with deposits in other basins of the Borborema Province (Riacho do Tigre in the Central Domain; Macurure and Maranco in the Sergipano Belt of the Southern domain). The Macaubas Group from SE Brazil and its counterparts in Africa, the Zadanian and Mayumbian Groups, in the western edge of the Congo Craton are also coeval. Closure of the Riacho Gravata and Sao Caetano basins occurred during the Brasiliano convergence (705-600 Ma). During the last stage of convergence, ca. 612 Ma, pull-apart basins were created and filled; final basin closure took place 605-592 Ma, after deposition ceased. (C) 2011 Elsevier B.V. All rights reserved.

Ages (U-Pb SHRIMP and LA ICPMS) and stratigraphic evolution of the Neoproterozoic volcano-sedimentary successions from the extensional Camaqua Basin, Southern Brazil

During the Ediacaran, southern Brazil was the site of multiple episodes of volcanism and sedimentation, which are best preserved in the 3000 km(2) Camaqua Basin. The interlayered sedimentary and volcanic rocks record tectonic events and paleoenvironmental changes in a more than 10 km-thick succession. In this contribution, we report new U-Pb and Sm-Nd geochronological constraints for the 605 to 580 Ma Born Jardim Group, the 570 Ma Acampamento Velho Formation, and a newly-recognized 544 Ma volcanism. Depositional patterns of these units reveal the transition from a restricted, fault-bounded basin into a wide, shallow basin. The expansion of the basin and diminished subsidence rates are demonstrated by increasing areal distribution and compressed isopachs and increasing onlap of sediments onto the basement to the west. The Sm-Nd isotopic composition of the volcanic rocks indicates mixed sources, including crustal rocks from the adjacent basement. Both Neoproterozoic and Paleoproterozoic sources are indicated for the western part of the basin, whereas only the older Paleoproterozoic signature can be discerned in the eastern part of the basin. (C) 2011 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved.

Space-time relation of post-collisional granitic magmatism in Santa Catarina, southern Brazil: U-Pb LA-MC-ICP-MS zircon geochronology of coeval mafic-felsic magmatism related to the Major Gercino Shear Zone

LA-MC-ICP-MS U-Pb zircon dating was performed on syntectonic, early post-collisional granitic and associated mafic rocks that are intrusive in the Brusque Metamorphic Complex and in the Florianopolis Batholith, major tectonic domains separated by the Neoproterozoic Major Gercino Shear Zone (MGSZ) in south Brazil. The inferred ages of magmatic crystallization are consistent with field relationships, and show that the syntectonic granites from both domains are similar, with ages around 630-620 Ma for high-K calc-alkaline metaluminous granites and ca. 610 Ma for slightly peraluminous granites. Although ca. 650 Ma inherited zircon components are identified in granites from both domains, important contrasts on the crustal architecture in each domain are revealed by the patterns of zircon inheritance, indicating different crustal sources for the granites in each domain. The granites from the southern domain (Floriandpolis Batholith) have essentially Neoproterozoic (650-700 Ma and 900-950 Ma) inheritance; with a single 2.0-2.2 Ga inherited age obtained in the peraluminous Mariscal Granite. In the northern Brusque Metamorphic Complex, the metaluminous Rio Pequeno Granite and associated mafic rocks have scarce inherited cores with ages around 1.65 Ga, whereas the slightly peraluminous Serra dos Macacos Granite has abundant Paleoproterozoic (1.8-2.2 Ga) and Archean (2.9-3.4 Ga) inherited zircons. Our results are consistent with the hypothesis that the MGSZ separates domains with distinct geologic evolution; however, the contemporaneity of 630-610 Ma granitic magmatism with similar structural and geochemical patterns on both sides of this major shear zone indicates that these domains were already part of a single continental mass at 630 Ma, reinforcing the post-collisional character of these granites. (C) 2012 Elsevier B.V. All rights reserved.

U-Pb dating by zircon dissolution method using chemical abrasion

Chemical abrasion was carried out on zircons grains of the Temora II standard for U-Pb dating prior to analyses using in situ Laser Ablation-MultiCollector Ion Coupled Plasma Mass Spectrometer (LA-ICPMS) followed by the Isotope Dissolution Thermal Ionization Mass Spectrometer (ID-TIMS) method. The proposed methodology was herein applied in order to reduce primarily the effects of secondary Pb loss, the presence of common lead and/or silicate impurities. Nine Temora II zircon grains were analyzed by the laser ablation method yielding an age of 418.3±4.3 Ma. Zircon grains of a same population were separated for chemical abrasion before dissolution and mass spectrometry analyses. Six fractions of them were separated for isotope dissolution using 235U-205Pb mixed spike after we have checked and assured the laboratory conditions of low blank values for total Pb of less than 2 pg/g. The obtained U-Pb zircon age by the ID-TIMS method was 415.7±1.8 Ma (error 0.43 %) based on four successful determinations. The results are consistent with the published ages for the Temora diorite (Temora I â 416.75±1.3 Ma; Temora II â 416.78±0.33 Ma) and established as 416±0.33 Ma. The technique is thus recommended for high precision U-Pb zircon analyses (error < 1 %), mainly for high resolution stratigraphic studies of Phanerozoic sequences.

U-Pb zircon in situ dating with LA-MC-ICP-MS using a mixed detector configuration

The LA-MC-ICP-MS method applied to U-Pb in situ dating is still rapidly evolving due to improvements in both lasers and ICP-MS. To test the validity and reproducibility of the method, 5 different zircon samples, including the standard Temora-2, ranging in age between 2.2 Ga and 246 Ma, were dated using both LA-MC-ICP-MS and SHRIMP. The selected zircons were dated by SHRIMP and, after gentle polishing, the laser spot was driven to the same site or on the same zircon phase with a 213 nm laser microprobe coupled to a multi-collector mixed system. The data were collected with a routine spot size of 25 μm and, in some cases, of 15 and 40 μm. A careful cross-calibration using a diluted U-Th-Pb solution to calculate the Faraday reading to counting rate conversion factors and the highly suitable GJ-1 standard zircon for external calibrations were of paramount importance for obtaining reliable results. All age results were concordant within the experimental errors. The assigned age errors using the LA-MC-ICP-MS technique were, in most cases, higher than those obtained by SHRIMP, but if we are not faced with a high resolution stratigraphy, the laser technique has certain advantages.

Petrogenesis of syntectonic granites emplaced at the transition from thrusting to transcurrent tectonics in post-collisional setting: Whole-rock and Sr-Nd-Pb isotope geochemistry in the Neoproterozoic Quatro Ilhas and Mariscal Granites, Southern Brazil

The Neoproterozoic post-collisional period in southern Brazil (650-580 Ma) is characterized by substantial volumes of magma emplaced along the active shear zones that compose the Southern Brazilian Shear Belt. The early-phase syntectonic magmatism (630-610 Ma) is represented by the porphyritic, high-K, metaluminous to peraluminous Quatro Ilhas Granitoids and the younger heterogranular, slightly peraluminous Mariscal Granite. Quatro II has Granitoids include three main petrographic varieties (muscovite-biotite granodiorite mbg; biotite monzogranite - bmz: and leucogranite - lcg) that, although sharing some significant geochemical characteristics, are not strictly comagmatic, as shown by chemical and Sr-Nd-Pb isotope data. The most primitive muscovite-biotite granodiorite was produced by contamination of more mafic melts (possibly with some mantle component) with peraluminous crustal melts; the biotite monzogranite, although more felsic, has higher Ca, MgO,TiO2 and Ba, and lower K2O, FeOt, Sr and Rb contents, possibly reflecting some mixing with coeval mafic magmas of tholeiitic affinity; the leucogranite may be derived from pure crustal melts. The Mariscal Granite is formed by two main granite types which occur intimately associated in the same pluton, one with higher K (5-6.5 wt.% K2O) high Rb and lower CaO, Na2O, Ba and Zr as compared to the other (3-5 wt.% of K2O). The two Mariscal Granite varieties have compositional correspondence with fine-grained granites (fgg) that occur as tabular bodies which intruded the Quatro Ilhas Granoitoids before they were fully crystallized, and are inferred to correspond to the Mariscal Granite feeders, an interpretation that is reinforced by similar U-Pb zircon crystallization ages. The initial evolution of the post-collisional magmatism, marked by the emplacement of the Quatro Ilhas Granitoids varieties, activated sources that produced mantle and crustal magmas whose emplacement was controlled both by flat-lying and transcurrent structures. The transition from thrust to transcurrent-related tectonics coincides with the increase in the proportion of crustal-derived melts. The transcurrent tectonics seems to have played an essential role in the generation of mantle-derived magmas and may have facilitated their interaction with crustal melts which seem to be to a large extent the products of reworking of orthogneiss protoliths. (C) 2012 Elsevier B.V. All rights reserved.

Depositional age, provenance and metamorphic age of metasedimentary rocks from southern Madagascar

Southern Madagascar is the core of a >1 million km(2) Gondwanan metasedimentary belt that forms much of the southern East African Orogen of eastern Africa, Madagascar, southern India and Sri Lanka. Here the Vohibory Series yielded U-Pb isotopic data from detrital zircon cores that indicate that it was deposited in the latest Tonian to late Cryogenian (between -900 and 640 Ma). The deposition of the Graphite and Androyen Series protoliths is poorly constrained to between the late Palaeoproterozoic and the Cambrian (similar to 1830-530 Ma). The Vohibory Series protoliths were sourced from very restricted-aged sources with a maximum age range between 910 and 760 Ma. The Androyen and Graphite Series protoliths were sourced from Palaeoproterozoic rocks ranging in age between 2300 and 1800 Ma. The best evidence of the timing of metamorphism in the Vohibory Series is a weighted mean Pb-206/U-238 age of 642 +/- 8 Ma from 3 analyses of zircon from sample M03-01. A considerably younger Pb-206/U-238 metamorphic age of 531 +/- 7 Ma is produced from 10 analyses of zircon from sample M03-28 in the Androyen Series. This similar to 110 Ma difference in age is correlated with the early East African Orogeny affecting the west of Madagascar along with its type area in East Africa, whereas the Cambrian Malagasy Orogeny affected the east of Madagascar and southern India during the final suturing of the Mozambique Ocean. (C) 2011 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved.

The growth of large mafic intrusions: Comparing Niquelandia and Ivrea igneous complexes

The Niquelandia Complex, Brazil, is one of the world's largest mafic-ultramafic plutonic complexes. Like the Mafic Complex of the Ivrea-Verbano Zone, it is affected by a pervasive high-T foliation and shows hypersolidus deformation structures, contains significant inclusions of country-rock paragneiss, and is subdivided into a Lower and an Upper Complex. In this paper, we present new SHRIMP U-Pb zircon ages that provide compelling evidence that the Upper and the Lower Niquelandia Complexes formed during the same igneous event at ca. 790 Ma. Coexistence of syn-magmatic and high-T subsolidus deformation structures indicates that both complexes grew incrementally as large crystal mush bodies which were continuously stretched while fed by pulses of fresh magma. Syn-magmatic recrystallization during this deformation resulted in textures and structures which, although appearing metamorphic, are not ascribable to post-magmatic metamorphic event(s), but are instead characteristic of the growth process in huge and deep mafic intrusions such as both the Niquelandia and Ivrea Complexes. Melting of incorporated country-rock paragneiss continued producing hybrid rocks during the last, vanishing stages of magmatic crystallization. This resulted in the formation of minor, late-stage hybrid rocks, whose presence obscures the record of the main processes of interaction between mantle magmas and crustal components, which may be active at the peak of the igneous events and lead to the generation of eruptible hybrid magmas. (C) 2012 Elsevier B.V. All rights reserved.

Neoproterozoic glacial deposits from the Aracuai orogen, Brazil: Age, provenance and correlations with the Sao Francisco craton and West Congo belt

Glacigenic diamictite successions of the Macaubas Group are widespread in the western domain of the Aracuai orogen, east of the Sao Francisco craton (Brazil). Diamictites also occur on this craton and in the African counterpart of the Aracuai orogen, the West Congo belt. Detrital zircon grains from the matrix of diamictites and sandstones from the Macaubas Group were dated by the U-Pb SHRIMP technique. The geochronological study sets the maximum depositional age of the glacial diamictites at 900 Ma, and indicates multiple sources for the Macaubas basin with ages ranging from 900 to 2800 Ma. Sm-Nd T-DM model ages, determined on whole rock samples, range from 1.8 Ga to 2.5 Ga and get older up-section. Comparison of our data with those from the cratonic area suggest that these glacial deposits can be correlated to the Jequitai and Carrancas diamictites in the Sao Francisco craton, and to the Lower Mixtite Formation of the West Congolian Group, exposed in Africa. The 900-1000 Ma source is most probably represented by the Zadinian-Mayumbian volcanic rocks and related granites from the West Congo belt. However, one of the most voluminous sources, with ages in the 1.1-1.3 Ga interval, has not been detected in the Sao Francisco-Congo craton. Possible sources for these grains could occur elsewhere in Africa, or possibly from within the Brasilia Belt in western central Brazil. (C) 2011 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved.

Time constraints on magmatism along the Major Gercino Shear Zone, southern Brazil: Implications for West Gondwana reconstruction

The Dom Feliciano Belt, situated in southernmost Brazil and Uruguay, contains a large mass of granite-gneissic rocks (also known as Florianopolis/Pelotas Batholith) formed during the pre-, syn- and post-orogenic phases of the Brasiliano/Pan-African cycle. In the NE extreme of this granitic mass, pre-, syn- and post-tectonic granites associated with the Major Gercino Shear Zone (MGSZ) are exposed. The granitic manifestation along the MGSZ can be divided into pre-kinematic tonalitic gneisses, peraluminous high-K calcalkaline early kinematic shoshonitic, and metaluminous post-kinematic granites. U-Pb zircon data suggest an age of 649 +/- 10 Ma for the pre-tectonic gneisses, and a time span from 623 +/- 6 Ma to 588 +/- 3 Ma for the early to post-tectonic magmatism. Negative epsilon Hf (t) values ranging from -4.6 to -14.6 and Hf model ages ranging from 1.64 to 2.39 Ga for magmatic zircons coupled with whole rock Nd model ages ranging from 1.24 to 2.05 Ga and epsilon Nd (t) values ranging from -3.84 to -7.50, point to a crustal derivation for the granitic magmatism. The geochemical and isotope data support a continental magmatic arc generated from melting of dominant Paleoproterozoic crust, and a similar evolution for the granitic batholiths of the eastern Dom Feliciano Belt and western Kaoko Belt. (C) 2011 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved.

Ordovician A-type granitoid magmatism on the Ceara Central Domain, Borborema Province, NE-Brazil

We present field relationships, major and trace element geochemistry and U-Pb SHRIMP and ID-TIMS geochronology of the A-type Ordovician Quintas pluton located in the Ceara Central Domain of the Borborema Province, in northeastern Brazil. This pluton presents a concentric geometry and is composed mainly of syenogranite, monzogranite, quartz syenite to quartz monzodiorite, monzogabbro and diorite. Its geochemical characteristics [SiO2 (52-70%), Na2O/K2O (1.55-0.65), Fe2O3/MgO (2.2-7.3), metaluminous to sligthly alkaline affinity, post-collisional type in (Y + Nb) x Rb diagram, and A-type affinity (Ga > 22 ppm, Nb > 20 ppm, Zn > 60 ppm), REE fractioned pattern with negative Eu anomaly] are coherent with post-collisional A(2)-type granitoids. However, the emplacement of this pluton is to some extent temporally associated with the deposition of the first strata of the Parnaiba intracratonic basin, attesting also to a purely anorogenic character (A(1)-type granitoid). The emplacement of this pluton is preceded by one of the largest known orogenesis of the planet (Neoproterozoic Pan-African/Brasiliano) and, if it is classified as an A(2)-type granitoid, it provides interesting constraints about how long can last A(2)-type magmatic activity after a major collisional episode, arguably triggered by disturbance of the underlying mantle, a topic extensively debated in the geoscience community. (C) 2011 Elsevier Ltd. All rights reserved.

Petrology and Sr-Nd characteristics of the Nova Lacerda dike swarm, SW Amazonian Craton: new insights regarding its subcontinental mantle source and Mesoproterozoic geodynamics

The NNW-trending Nova Lacerda tholeiitic dike swarm in Mato Grosso State, Central Brazil, intrudes the Nova Lacerda granite (1.46 Ga) and the Jauru granite-greenstone terrain (ca. 1.79-1.77 Ga). The swarm comprises diabases I and II and amphibolites emplaced at ca. 1.38 Ga. Geochemical data indicate that these are evolved tholeiites characterized by high LILE/HSFE and LREE/HSFE ratios. Isotopic modelling yields positive epsilon(Nd)(T) values (+0.86 to +2.65), whereas values for epsilon(Sr)(T) range from positive to negative (+1.96 to -5.56). Crustal contamination did not play a significant petrogenetic role, as indicated by a comparison of isotopic data (Sr-Nd) from both dikes and country rocks, and by the relationship between isotopic and geochemical parameters (SiO2, K2O, Rb/Sr, and La/Yb) of the dikes. We attribute the origin of these tholeiites to fractional crystallization of evolved melts derived from a heterogeneous mantle source. Comparison of the geochemical and isotopic data of the studied swarm and other tholeiitic Mesoproterozoic mafic intrusions of the SWAmazonian Craton the Serra da Providencia, Colorado, and Nova Brasilandia bimodal suites - indicates that parental melts of the Nova Lacerda swarm were derived from the most enriched mantle source. This enrichment was probably caused by the stronger influence of the EMI component on the DMM end-member. These data, coupled with trace element bulk-rock geochemistry of the country rocks, and comparisons with the Colorado Complex of similar age, suggest a continental-margin arc setting for the emplacement of the Nova Lacerda dikes.

Complex, 3D strain patterns in a synkinematic tonalite batholith from the Aracuai Neoproterozoic orogen (Eastern Brazil): Evidence from combined magnetic and isotopic chronology studies

This work combines structural and geochronological data to improve our understanding of the mechanical behaviour of continental crust involving large amount of magma or partially melted material in an abnormally hot collisional belt. We performed a magnetic and geochronological (U/Pb) study on a huge tonalitic batholith from the Neoproterozoic Aracual belt of East Brazil to determine the strain distribution through space and time. Anisotropy of magnetic susceptibility, combined with rock magnetism investigations, supports that the magnetic fabric is a good proxy of the structural fabric. Field measurements together with the magnetic fabrics highlight the presence in the batholith of four domains characterized by contrasted magmatic flow patterns. The western part is characterized by a gently dipping, orogen-parallel (similar to NS) magmatic foliation that bears down-dip lineations, in agreement with westward thrusting onto the Sao Francisco craton. Eastward, the magmatic foliation progressively turns sub-vertical with a lineation that flips from sub-horizontal to sub-vertical over short distances. This latter domain involves an elongated corridor in which the magmatic foliation is sub-horizontal and bears an orogen-parallel lineation. Finally the fourth, narrow domain displays sub-horizontal lineations on a sub-vertical magmatic foliation oblique (similar to N150 degrees E) to the trend of the belt. U/Pb dating of zircons from the various domains revealed homogeneity in age for all samples. This, together with the lack of solid-state deformation suggests that: 1) the whole batholith emplaced during a magmatic event at similar to 580 Ma, 2) the deformation occurred before complete solidification. and 3) the various fabrics are roughly contemporaneous. The complex structural pattern mapped in the studied tonalitic batholith suggests a 3D deformation of a slowly cooling, large magmatic body and its country rock. We suggest that the development of the observed 3D flow field was promoted by the low viscosity of the middle crust that turned gravitational force as an active tectonic force combining with the East-West convergence between the Sao Francisco and Congo cratons. (C) 2012 Elsevier Ltd. All rights reserved.