3.30 Ga High-Silica Intraplate Volcanic-Plutonic System of the Gavião Block, São Francisco Craton, Brazil: possible Silicic Large Igneous Province
Stefano A. Zincone a,b, Elson P. Oliveira a, Oscar Laurent c, Hong Zhang d, Mingguo Zhai e
a Department of Geology and Natural Resources, Institute of Geosciences, University of Campinas, P.O. Box 6152, 13083-970 Campinas, Brazil
b Department of Geology, School of Mine, Federal University of Ouro Preto, Brazil
c Université de Liège, Département de Géologie B20, Quartier Agora, Allée du six Août 12, B-4000 Liège, Belgium
d State Key Laboratory of Continental Dynamics, Department of Geology, Northwest University, 229 Taibai road, Beilin District, Xi’an, 710069 China
e Institute of Geology and Geophysics, Chinese Academy of Sciences, 19 Beitucheng Xilu Street, Beijing, 100049 China
E-mail address: email@example.com (S. Zincone)
Extracted and modified after: Zincone, S. A., Oliveira, E. P., Laurent, O., Zhang, H., Zhai, M. 2016. 3.30 Ga high-silica intraplate volcanic–plutonic system of the Gavião Block, São Francisco Craton, Brazil: Evidence of an intracontinental rift following the creation of insulating continental crust. Lithos, 266, 414-434.
For full details see that paper.
Most intraplate volcanic systems, such as silicic large igneous provinces (SLIPs), bimodal volcanic systems, oceanic islands and oceanic plateaux, compositionally differ from magmas generated at plate boundaries, with the former being hotter, drier and induced by anhydrous decompression melting, and the latter are typically colder, H2O-rich and formed by fluid-driven flux melting (Bailey, 1983; Grove et al., 2012; Lee and Bachmann, 2014). Intraplate magmatism generally affects continental or oceanic interiors undergoing extension and is actively driven by narrow mantle plumes originating from relatively shallow asthenosphere upwelling (Anderson and King, 2014), or passively driven by plate motion (Ziegler and Cloetingh, 2004). The addition of underplating mafic magma in intraplate environment provides a “non-plate tectonics” way for crustal growth and thickening (Thybo and Artemieva, 2013), and may contribute to remelting of parts of the original crust. The continuous underplating of mafic magmas causes the progressive differentiation of the continental lithosphere and stabilization by lower crustal delamination events (e.g., Bédard, 2006; Johnson et al., 2013).
Tonalite-trondhjemite-granodiorite suites (TTGs) represent the dominant lithology of Archean crust (Arndt, 2013; Moyen, 2011), especially for the Eo- and Paleoarchean periods (4.0-3.2 Ga). However, several recent studies have emphasized that Eo- to Paleoarchean crustal segments often contain a diversity of granitoids that are not all akin to TTGs. Some examples are the ca. 4.02 Ga Idiwhaa tonalites in the Slave craton, NW Canada (Reimink et al., 2014); the ca. 3.60 Ga ferroan augen gneiss suite in the North Atlantic Craton of SW Greenland (Friend and Nutman, 2005; Nutman et al., 1996); as well as some components of the 3.66-3.45 Ga Ancient Gneiss Complex (Hoffmann et al., 2016) of the eastern Kaapvaal Craton in southern Africa. Although subordinate in volume, these felsic rocks may represent important geodynamic events in the process of craton building and stabilization and must be considered along with TTG to depict the processes of Archean crust evolution. Specifically, petrogenetic studies of these non-TTG components showed that they likely formed in intraplate settings in which the crust is heated up by mantle upwelling and mafic magma underplating (Nutman et al., 1984; Hoffmann et al., 2014; Reimink et al., 2014), which could be interpreted as the result of a mantle plume impingement at the base of a preexisting continental crust.
Therefore, in order to better constrain the role of these processes in the formation and evolution of continental lithosphere in the early Earth, it is necessary to better characterize and study the origin of non-TTG components in Eo- to Paleoarchean terranes. Felsic 3.30 Ga-old volcanic rocks and associated granitoids occur at the eastern margin of Gavião Block, São Francisco craton, in association with the Contendas-Mirante and Mundo Novo supracrustal belts (Marinho et al., 1994; Peucat et al., 2002). They are geologically and petrologically unrelated to classical TTGs. Zincone et al (2016) described the petrology, whole-rock geochemistry, zircon U-Pb ages and Lu-Hf isotopic signatures of these felsic and plutonic rocks. Based on those data and coupled with geochemical modeling those authors investigate the nature of the source and interpreted the magmatic evolution as an inter-related high-silica plutonic-volcanic system formed in an intracontinental tectonic setting following the creation of insulating continental crust. The combined results were used to discuss the tectonic environment of the volcanic-plutonic system related to the evolution of the Gavião Block and to explore the general role that intraplate magmatism might play in craton formation and evolution. Here, we used the combined results to speculate about the possibility of the 3.30 Ga plutonic-volcanic system be a SLIP.
2. Geological setting
The São Francisco Craton (Fig. 1) comprises Archean and Paleoproterozoic terranes of low-grade to granulitic metamorphic facies. The Gavião Block forms the western segment of the São Francisco basement. It mainly consists of 3.40 - 3.33 Ga granitic gneiss complexes with TTGs and medium- to high-K calc-alkaline composition (Martin et al., 1997; Nutman and Cordani, 1993; Santos-Pinto et al., 1998, 2012; Marchesin, 2015; Zincone, 2016) and the 3.30 Ga plutonic-volcanic system (Zincone et al., 2016).
Figure 1: Simplified geological map of the São Francisco Craton (modified after Silva et al., 2015). The letters indicate the four main complexes within the Gavião Block; P: Porteirinha Complex; G: Gavião Complex; M: Mairi Complex; S: Sobradinho Complex. The red rectangle represents the area covered by Fig. 2.
The rhyolites occur associated with two distinct supracrustal sequences that occur 200 km apart from each other (Fig. 2A). The north Mundo Novo supracrustal belt (Fig, 2 B; Mascarenhas and Silva, 1994; Peucat et al., 2002) represents an intracratonic basin, with felsic volcanism and a continental to marine sedimentary sequence (Loureiro and Santos, 1991). The 3.30 Ga Contendas Rhyolite occurs in the southern sector, partly overlain by the Paleoproterozoic Contendas-Mirante basin (Fig. 2 C; Nutman et al., 1994; Zincone and Oliveira, in review). The Jacobina Basin, occurring west of the Mundo Novo belt, comprises siliciclastic units containing only 3580 to 3280 Ma detrital zircon grains, with the most abundant population at 3300 Ma (Teles et al., 2015; Barbuena et al., 2016), and was developed on the stable platform represented by >3.4 Ga gray gneiss of the Gavião Block (see Mascarenhas et al., 1998 and Pearson et al., 2005 for a review). Similar 3350 to 3280 Ma zircon-bearing quartzite has been recently described in spatial association with the investigated rhyolites (Zincone, 2016; Zincone and Oliveira, in review; Barbuena et al., 2016).
Figure 2: Simplified geological map of Contendas-Jacobina lineament at the eastern border of Gavião Block (modified from; Mascarenhas et al., 1998). In the south the low metamorphic grade Paleoproterozoic Contendas-Mirante Basin is sandwiched between the Gavião and Jequié blocks, and it is correlated with the northern Saúde basin. The grey rectangle represents the area covered by Fig. B and C, showing the geological map for the Mundo Novo Rhyolite and the Contendas Rhyolite, respectively.
3. Geological setting and petrography of the rhyolites and coeval plutonic rocks
The contact between rhyolite and basement gneisses or metasedimentary rocks is not observed; the volcanic rocks occur as inliers within Paleoproterozoic cover. The rhyolites are not interlayered with any other meta-volcanic unit and the maximum metamorphic grade is lower greenschist facies. For details on the petrography of the units see Zincone et al. (2016).
Plutonic rocks occur in the vicinity of both investigated rhyolites. The Boa Sorte meta-syenogranite is a pluton emplaced within the grey gneisses complex. The 3.35 Ga Boa Vista dome (Nutman and Cordani, 1993) occurs in the southern part of the Contendas-Mirante basin. The northeastern portion is largely composed of biotite meta-granite (sample TZD-199A) cut by albite granite dykes. The Calderão diorite gneiss is located between the Sete Voltas and Boa Vista domes.
4. Zircon U-Pb-Hf studies and whole-rock geochemistry
4.1. U-Pb geochronology
Zincone et al (2016) investigated four samples for geochronology: two rhyolite and two granite. Zircon grains in all four samples show similar shapes (perfectly euhedral, translucent, colorless to light pink stubby prisms ranging from 150 to 400 μm and aspect ratio of 3:1), concentric oscillatory zoning with no overgrowths and concordant U-Pb ages (Fig. 3). The rhyolites lack zircon xenocrysts and core-rim relationships. The igneous zircon crystallization occurred in the late stages of magma cooling and holds high zircon saturation temperature (ranging from 833 to 915 oC). Zircon Th/U ratios are ~0.5 in the rhyolites and slightly higher (0.7-0.8) in the granites. The two rhyolites present the same Concordia age of 3304.3 ± 8.2 Ma and 3303.7 ± 11 Ma. The granites present distinct crystallization age of 3292 ± 3 Ma for Boa Sorte biotite meta-granite and of 3327.7 ± 3 Ma for the Boa Vista biotite meta-granite.
Figure 3: Concordia diagrams (206Pb/238U vs. 207Pb/235U) for LA-ICP-MS zircon analyses on samples from the Contendas (13°40'10.40"S; 40°54'22.46"W) and Mundo Novo (11°53'36.79"S; 40°29'25.08"W) rhyolites and from the Boa Sorte (12°14'1.82"S; 40°34'27.43"W) and Boa Vista (14°22'38.59"S; 40°44'47.77"W) granites, the plutonic equivalent of the rhyolites. Error ellipses are 2σ.
4.2. Zircon Hf isotopes
Hf-in-zircon analyses were carried on the rhyolites. The 176Hf/177Hf(3.3 Ga) ratios overlap for both rhyolites, but are very heterogeneous (ranging from 0.280474 to 0.280659). Most of the corresponding εHf(3.3 Ga) values are negative ranging between 0.35 and -6.26 (TDM from 3.54 and 3.88 Ga; Fig. 4).
Figure 4: Composite Hf isotope evolution diagram. (a) 40 analyses from Contendas Rhyolite; (b) 30 analyses from Mundo Novo Rhyolite. 176Lu/177Hf evolution lines are based on assumed 176Hf/177Hf crustal ratio of 0.0113 (Bouvier et al. 2008). The 176Lu decay constant of Söderlund et al. (2004) and Scherer et al. (2001) were used in the calculation of εHf(3.3 Ga) values.
4.3. Whole-rock geochemistry
The two spatially distinct rhyolites show strikingly similar major and trace element signatures. All samples are silica oversaturated with more than 43% normative quartz and SiO2 ranging from 74 to 79 wt.%. They have low Al2O3 (<11 wt.%) contents and K2O/Na2O ratios between 0.5 and 1. The MNR samples display higher MgO (average 1.07 wt.%) and lower CaO (average 0.18wt.%) than the CR (average MgO 0.48 wt.%; CaO = 0.73%wt). Intriguingly, the most silica-rich samples are also the richer in MgO. The two rhyolite units are also depleted in ferromagnesian elements (Fe2O3(T)+MgO+MnO+TiO2 < 4.4 wt.%), with relatively high Cr (5-24 ppm) and low Ni (<1 ppm) contents.
On classification diagrams the samples fall in the sub-alkaline rhyolite field and show a narrow compositional range from rhyolite to quartz keratophyre (Fig. 5 A-C). The CR samples classify as metaluminous to slightly peraluminous, ferroan calcic rocks whereas the MNR samples are slightly to strongly peraluminous, ferroan to magnesian calcic rocks (Fig. 5D). All the samples match the medium-K calc-alkaline fields on the AFM diagram and SiO2 vs K2O plot.
Figure 5: Classification diagrams. A) Total alkalis vs. silica diagram (Middlemost, 1994); B) Nb/Y vs. Zr/TiO2 (Winchester and Floyd, 1977). C) Ternary diagram of feldspar: Ab - albite; An - anortite; Or – orthoclase (O'Connor, 1965); black field represents the TTG series and gray field represents the calc-alkaline series commonly related to modern continental arcs (BADR” suites). D) Classification diagrams for granitic rocks. Alumina saturation index (molecular [Al2O3/(CaO+Na2O+ K2O)]) against partial saturation index (molecular [Al2O3/(Na2O+ K2O)]) (Shand, 1943). Fe# [(Fe2O3(T)/(Fe2O3(T)+MgO)] vs SiO2. The ferroan signature is given when Fe# > 0.486 + 0.0046 x SiO2 wt.% (Frost et al., 2001). MALI index (Na2O+ K2O-CaO) vs. SiO2 plot showing the calcic affinity from the rhyolites.
The rhyolites display strong depletions in Sr and Ti, and moderate Nb-Ta negative anomalies. In addition, they are depleted in Rb relative to Th and enriched in Ba relative to Sr (Fig. 6 A). The REE patterns (Fig. 6 B) of both rhyolite units show no difference and present slight enrichment of the light REE relative to heavy REE (average La/Yb(N) ratio = 4.75) and marked negative Eu anomalies (Eu/Eu* = 0.55).
Figure 6: Spider diagrams. A) Mantle-normalized multi-element diagram. Normalizing values after McDonough and Sun (1995). B) Chondrite-normalized REE diagram. Normalizing values from McDonough and Sun (1995).
The Calderão diorite is an intermediate (58 wt.% SiO2) metaluminous and alkali-calcic rock of ferroan affinity (Fig. 5 D). It is poorer in K2O, SiO2 and richer in Fe2O3(T), MgO, CaO and Al2O3 than the granite and rhyolites. Although it has comparable profiles in multi-element diagrams and REE patterns, the Calderão diorite is also distinguished from the more felsic rocks by its lower contents in highly incompatible elements, less pronounced Nb, Ta, Sr and Ti troughs in primitive mantle normalized trace element diagrams, the absence of a negative Eu anomaly (EuN/Eu* = 0.92) and lower HREE contents (La/YbN = 18.8).
5.1. Element mobility
Some MNR samples are characterized by shear planes filled with recrystallized muscovite and present green biotite and chlorite, resulting in strongly peraluminous character (Fig. 5 D). Their peculiar composition might thus reflect superimposed metasomatism due to focused fluid-flow regimes during later tectonothermal events. The fluid-dominated alteration modified some of their mineralogy and major element chemistry, but did not affect the trace element patterns (Fig. 6).
Asides from the most deformed samples, element mobility due to post-crystallization events seems to be minor or even absent, which is in line with preserved igneous textures and mineralogy. Specifically, the lack of any clear negative correlation between silica, other major element, and trace element contents argues against any role played by silicification in the generating the high-SiO2 content of these rocks.
5.2. Petrogenetic modeling
In order to constrain the differentiation processes and the source, we compared the major element composition of the rhyolites with experimental melts relevant for crustal melts (i.e. P <1.5 GPa; T <1200°C; SiO2 >70 wt.%.). The tight compositional range of the rhyolites indicates that they represent near-liquid compositions. In contrast, the Boa Sorte and Boa Vista granites show compositions that are closer to the field of experimental leucogranites. These granites and the rhyolites share compositional affinities and define rough linear trends in Harker diagrams. We therefore propose that they are cogenetic and specifically that the rhyolites represent differentiated liquids from a parental composition close to that of the granites. This suggests two-step mechanism with (1) derivation of the granites by partial melting of crustal rocks or crystallization of a mafic magma and (2) further differentiation of the granitic bulk composition to form the rhyolites. This two-step model is consistent with petrogenetic models of recent high-SiO2 rhyolites, indicating that these represent extracted liquids from crystal mushes formed in magma chambers of intermediate-felsic composition (Bégué et al., 2014; Dufek and Bachmann, 2010; Graeter et al., 2015).
We used least-squares mass balance calculations on major elements to check if the inferred two-step petrogenetic model (Calderão diorite → Boa Sorte granite → MNR and CR rhyolites) was plausible. See details of modelling in Zincone et al. (2016).
It must be noted that the entire process modelled is consistent with the formation of large volumes of rhyolites by segregation of residual melt within long-lived, crystallizing mush zones, as described in modern settings in which granitoids represent the leftovers of large rhyolitic eruptions (Bachmann and Bergantz, 2004, 2008; Gelman et al., 2014; Lipman and Bachmann, 2015). Moreover, the model predicts that the bulk proportion of fractionated crystals relative to the initial amount of melt is c. 50%. This is consistent with the results of numerical models showing that the probability of residual melt extraction in crystal mushes (and thus ascent and eruption of high-SiO2 rhyolites) dramatically increases as soon as the crystal fraction reaches c. 50%, irrespective of the initial melt composition and size of the magma chamber (Dufek and Bachmann, 2010).
The two-step model was tested and supported using trace element modelling as detailed in Zincone et al. (2016).
5.3. Interpretation of Hf isotope data
The large variations observed in zircon εHf(3.3 Ga) most likely reflects heterogeneous Hf isotopic composition of the magma from which zircon crystallized. The results of geochemical modelling suggest that differentiation of a parent dioritic liquid formed a granitic magma, crystallized at relatively shallow (<10 km) reservoirs and from which highly silicic residual liquid was extracted to erupt as rhyolites. In the scope of this model, the heterogeneous Hf isotopic composition of the rhyolites could result from two (non-exclusive) scenarios: (i) the source (i.e. diorite parent) itself had a heterogeneous Hf isotopic composition (e.g., Belousova et al., 2006; Kemp et al., 2008; Appleby et al., 2010; Kröner et al., 2013); or (ii) the granites and rhyolites were formed by disequilibrium partial melting of the zircon-bearing diorite source, with zircon specifically remaining in the residual phase, which is able to produce large variations in Hf isotopic compositions of the resulting melts (Tang et al., 2014; Gerdes and Zeh, 2009; Laurent and Zeh, 2015).
Despite the variation, almost all zircon εHf(3.3 Ga) values in the rhyolites are negative. In this respect, the two possible differentiation mechanisms of dioritic material for the origin of granites and rhyolites have different implications. The crystal fractionation model implies that the latter had itself a negative and heterogeneous εHf(3.3 Ga), most likely implying crustal contamination of the parent, mantle-derived diorite magma. If partial melting is considered, then it means that the diorite may have had a juvenile isotope composition at the time of emplacement and, in that case, be much older (>3.5 Ga). In either case, the negative εHf(3.3 Ga) of zircons in the studied rhyolites indicate that the rhyolite magmatism contributed to the reworking of older crustal components, potentially as old as 3.5 - 4.0 Ga according to the Hf model ages.
5.4. Comparison with other Archean granitoids and tectonic settings
The studied granites and rhyolites are completely different compared with major and trace element features of the most common Archean granitoid types, such as TTGs, sanukitoid and crust-derived granites (e.g. Laurent et al., 2014a; Moyen, 2011; Martin et al., 2014; Condie, 2014), precluding any affinity with these rocks (Fig. 7 A-B). This observation, and the fact that the rhyolites are younger than the 3.40-3.33 Ga TTG and medium- to high-K calk-alkaline magmatism of the Gavião Block, contrasts strikingly with the relationship observed in most Paleoarchean terranes, where the felsic volcanics erupted in the greenstone belts are similar in composition to, and coeval with the associated TTG gneisses (Agangi et al., 2015; Smithies et al., 2007; Kohler and Anhaeusser, 2002).
Figure 7: Binary diagrams comparing the rocks of the volcanic-plutonic system from the Gavião Block with those from TTG suites and potassic granites of the calc-alkaline suites (fields from Moyen, 2011), Idiwhaa Tonalitic Gneiss (data from Reimink et al., 2014), and Itsaq Augen Gnaisse (data from Nutman et al., 1984). A and B) exploring the role of La, Yb, Y and Sr; TTG dataset from Martin et al. (1997) and normalizing values after McDonough and Sun (1995). A) La/Yb(N) vs. Yb(N). B) La/Yb(N) vs. Sr/Y (Condie and Kröner, 2013). C, D and E) Tectonic setting discrimination diagrams. C) Y+Nb vs Rb (Pearce et al. 1984). The tectonic fields were represented by syn-collision (syn-COL), volcanic arc (VA), within-plate (WP), oceanic ridge granite (ORG). TTG (dashed line) and potassic granites (grey) fields are from Moyen (2011). D) Nb vs Ga/Al (Whalen et al. 1987). E) Nb-Y-Ce (Eby, 1992).
The composition of coeval plutonic rocks regionally associated with the rhyolites and the Calderão diorite gneiss clearly plot along the same chemical trends as the rhyolites (Fig. 6). They are calc-alkaline, intermediate to felsic rocks ranging from 65 to 72 wt.% SiO2 and have high Fe2O3(T), CaO and Na2O (CaO/Na2O ratio of 0.5-0.6) contents. Like the rhyolites, they have slightly peraluminous and ferroan calcic compositions (Fig. 5 D) and similar trace element and REE patterns (Fig. 6 B), with slightly higher Rb, Th, Nb-Ta, Sr, La and Ti contents and lower Ba and HREE contents.
The granite and rhyolites have a distinctive trace element signature that makes the assessment of their tectonic setting even more ambiguous than it normally is for the Archean period (e.g., Bédard, 2006; Moyen and Martin, 2012; Fig. 7 A-B). Overall, the trace element signature of the rhyolites only indicates extensive plagioclase fractionation, thus depicting shallow melt segregation (<10 kbar; Moyen, 2011) and/or low H2O activity in the system (Beard and Lofgren, 1991; Bogaerts et al., 2006; Tatsumi and Suzuki, 2009).
On the other hand, the rhyolites and granites present a calcic ferroan affinity similar to some rare “A-type” magmas and, just like them, elevated HFSE and HREE contents together with low Al2O3 and CaO (Frost et al. 2001, 2011; Whalen et al., 1987). Although care must be taken when applying classical tectonic discrimination diagrams to Archean rocks (Condie, 2015; Moyen and Martin, 2012; Bédard, 2006), our samples consistently correspond to magmas formed away from convergent plate margins in all discrimination diagrams (Fig. 7 C-E). Altogether, these consistent observations suggest that the granites and rhyolites were formed in an intraplate environment.
5.5. Implications for the evolution of the Gavião Block
The plutonic-volcanic system studied here was emplaced forthwith a period of important continental lithosphere formation, represented by scarce 4.1-3.5 Ga remnants and major 3.42-3.33 Ga magmatism. The widespread magmatic activity is mainly constrained to the time span from 3.40 to 3.33 Ga and is represented by different 3.40-3.36 Ga TTG massifs (Martin et al., 1997; Guitreau et al., 2012; Nutman and Cordani, 1993; Santos-Pinto et al., 1998, 2012; Zincone, 2016) and 3.35-3.33 Ga medium- to high-K calk-alkaline magmatism (Marchesin, 2015; Zincone, 2016). The oldest Sete Voltas TTGs were interpreted as partial melts of Archean tholeiites leaving a garnet amphibolite residue (Martin et al., 1997). The partial melting of the older TTGs to produce younger porphyritic granodiorites was interpreted as reflecting crustal thickening to between 30 and 45 km by mechanisms similar to modern continental collision (Martin et al., 1997). In terms of Hf isotopic evolution, only zircon grains older than 3.42 Ga have positive εHf(t) values, while 3.43-3.37 Ga grains yield εHf(t) ranging from +2 to -5.4 (Guitreau et al., 2012).
The Jacobina basin and the related quartzites surrounding the investigated rhyolites contain abundant 3.55-3.28 Ga-old detrital zircons (Teles et al. 2015; Barbuena et al., 2016; Magee et al., 2001) (Fig. 8). Among those, many grains crystallized in the 3.43-3.30 Ga time span and show negative εHf(t) values between -0.1 and -7.4 (Teles et al., 2015) that overlap with both rhyolites, gbranites and TTGs. All lines of evidence suggest that the Jacobina basin and related quartzites represent an Archean supracrustal sequence deposited at a maximum age of ca. 3.28 Ga, and that the plutonic-volcanic system and TTGs of the Gavião Block were the main sources of detrital zircons and sediments. The abundance of ca. 3.30 Ga-old zircons in those siliciclastic units suggest that the volcanic-plutonic association described here represents the remnants of an eroded system that could have originally been largely.
Figure 8: U-Pb LA-ICP-MS age distribution frequency of less than 5% discordant detrital zircon grains from metasedimentary rocks associated with the Gavião Block using Kernel density estimation plot and data from Teles et al. (2015), Zincone and Oliveira (in review) and Zincone (2016).
The scenario that best reconciles all observations is that the ca. 3.30 Ga granite-rhyolite system represents the initial stage of an intra-continental rifting following a major 3.43-3.33 Ga period of continental lithosphere formation and stabilization; with continental break-up and deposition of siliciclastic sequences with maximum deposition age of ca. 3.28-3.26 Ga. Remarkably, the plutonic-volcanic system and the siliciclastic metasediments both occur along the paleo-margin of the Gavião Block, which supports that their emplacement was followed by continental break-up.
Moreover, close relationships between continental rift settings and silicic volcanism have frequently been observed in early Paleozoic intraplate magmatism (e.g. Carlton Rhyolite volcanic field; Hanson et al., 2013), modern extensional environments (e.g. Continental Rift: Yellowstone, EUA; Nash et al., 2006; Simakin and Bindeman, 2012; Drew et al., 2013, Huang et al. 2015, Rift Arc: Taupo Volcanic Zone, New Zealand; Allan et al., 2012; Bégué et al., 2014, Oceanic Rift: Iceland; Martin and Sigmarsson, 2007; Willbold et al., 2009), and specifically, represent the precursor stage for rift segment propagation events (e.g., Afar triple point; Lahitte et al., 2003).
5.6. Global perspective
To summary the interpretations above, the 3.30 Ga-old volcanic-plutonic system of the Gavião Block represents within-plate intracrustal magmatism following a burst of felsic crust magmatism during a period of transition between crustal stabilization and an early stage of continental break-up. Clearly, this model, together with the “crustal” zircon Hf isotopic signatures, suggest that reworking of a felsic protocrust and intracrustal differentiation processes did take place as early as 3.30 Ga in Earth's history, earlier than the 3.2 - 3.0 Ga or later age range proposed previously by other works (e.g., Laurent et al., 2014a and references therein).
Remarkably, the plutonic-volcanic system described here is similar in composition to some older high-SiO2 ferroan felsic rocks showing high HREE contents and negative Eu anomalies, such as the 4.02 Ga Idiwhaa tonalitic gneiss in Canada (Reimink et al., 2014) and the ca. 3.62 Ga iron-enriched augen gneisses and diorite intrusions at the Itsaq Gneiss Complex, Greenland (Nutman et al., 1984; Nutman et al., 1996) (Fig. 7). These rocks were respectively interpreted as reflecting shallow-level magmatic processes coupled with crustal assimilation of rocks previously altered by surface waters (Reimink et al., 2014); and differentiates from crustally-contaminated ferrodiorites and ferrogabbros ponded at the base of the crust (Nutman et al., 1984; 1996). In both cases, those rocks would have been formed in magmatically and/or tectonically thickened crust that underwent internal differentiation associated with intrusion of mafic mantle-derived magma in an intraplate extensional tectonic environment, similar to that inferred for the Gavião volcanic-plutonic system.
Such “intraplate” crustal differentiation processes appear to have been relatively common in the early Earth, even in the Eo- and Paleoarchean. It must be noted, however, that such intraplate magmatism did not produce TTGs but rather magmas of exotic, calcic ferroan compositions like the granites and rhyolites from the Gavião Block. This questions to some extent the validity (or at least the uniqueness) of “intraplate” models proposed to explain the genesis of TTGs.
5.7. Paleoarchean Silicic Large igneous Provinces?
Large Igneous Provinces (LIPs) comprise large (>100,000 km3) volumes of volcanic or near-surface intrusions often generated within 1-5 Ma in an intraplate setting or exhibiting intraplate characteristics (Bryan and Ernst, 2008; Bryan and Ferrari, 2013; Ernst, 2014), and reach life spans of 50 Ma when linked with volcanic rifted continental margins (Umhoefer, 2011). Those episodic intraplate provinces commonly are related to mantle plumes, either directly linked to plume-derived melts or indirectly associated to lower crustal-derived melts in which the heat source is probably a mantle plume itself (e.g., Campbell, 2005; Condie, 2016). Bryan and Ferrari (2013) (see also Bryan 2007) summarized that Silicic LIPs (SLIPs) “reflect their crustal setting along young, fertile continental margins built up by paleo subduction processes, and where crustal partial melting overwhelmed the igneous system”. However, for the Archean period (4.0-2.5 Ga) identifying SLIPs related to rifted continental margins is complicated by a more fragmentary, limited and ambiguous geological record. Furthermore, assuming a paleo subduction process in the building of Paleoarchean (>3 Ga) continental crust is also a matter of contention (e.g., Zegers and van Keken, 2001; Bédard, 2006; Smithies et al., 2003, 2009; Van Kranendonk, 2010, 2014; Martin et al., 2005, 2014; Dhuime et al., 2015). The effects of erosion, burial and tectonic fragmentation in the Paleoarchean are also matters of considered debate (e.g. Lowe and Tice, 2004; Hessler and Lowe, 2006) with the the plumbing system more likely preserved (Bryan and Ernst, 2008; Bryan and Ferrari, 2013). For the investigated 3.30 Ga rhyolites the interpretation about which part of the volcanic apparatus is still preserved and exposed is an open issue, mainly because they represent basement inliers.
One way to reveal SLIPs in the Archean can involve the integration of igneous and sedimentary records derived from erosion of the SLIP (e.g., Whitsunday; Bryan et al., 1997, 2012). In this case, the possibility that the evolution of the pre-rift 3.30 Ga plutonic-volcanic system, coupled with the development of the Jacobina rift basin, shows a reasonable hypothesis to integrate both as part of a Paleoarchean SLIP. Overall, the area extends for 600 km long, whereas the measured thickness of the Jacobina basin is 10 km thick and 20 km wide (e.g. see Pearson et al., 2005 for review). Moreover, if we consider that intracontinental rift ended up being tectonically fragmented, the true size and immensity of SLIP magmatism and basin infill could have originally been greater. The large volume of SLIP magmatism may have measurable effect on the detrital zircon age record within metasediments of the Jacobina basin (Fig. 8). Finally, it is important to call attention about the important links and feedbacks among the volcanism, lithospheric extension, crustal partial melting and continental rupture to generate SLIP magmatism (Ewart et al., 1992; Pankhurst and Rapela, 1995; Riley et al., 2001; Bryan et al., 2002, 2008), which is quite similar to the present model here proposed. The basaltic magma that may associate with the silicic magma can be thought as “hidden” mafic large igneous provinces (Ernst, 2014) or, as discussed on the geochemical modelling, be in part related to the Calderão diorites. Thus, we expect that this contribution will lead to new investigations aimed at overcoming possible contradictions and disagreements and point the way forward for understanding the evolution of the 3.30 Ga plutonic-volcanic system of the Gavião Block, and allow assessment of it as perhaps the world’s oldest SLIP.
Agangi, A., Hofmann, A., Kamenetsky, V.S., Vroon, P.Z., 2015. Palaeoarchaean felsic magmatism: A melt inclusion study of 3.45Ga old rhyolites from the Barberton Greenstone Belt, South Africa. Chemical Geology 414, 69–83.
Allan, A. S. R.,Wilson, C. J. N., Millet, M.A., Wysoczanski, R. J., 2012. The invisible hand: Tectonic triggering and modulation of a rhyolitic supereruption. Geology 40, 563-566.
Anderson, D.L., King, S.D., 2014. Driving the Earth machine? Science 346, 1184-1185.
Appleby, S.K., Gillespie, M.R., Graham, C.M., Hinton, R.W., Oliver, G.J., Kelly, N.M., 2010. Do S-type granites commonly sample infracrustal sources? New results from an integrated O, U–Pb and Hf isotope study of zircon. Contributions to Mineralogy and Petrology 160, 115-132.
Arndt, N. T., 2013. The formation and evolution of the continental crust. Geochemical Perspectives 2(3), 405-533.
Artemieva, I.M., 2006 Global 1°×1° thermal model TC1 for the continental lithosphere: Implications for lithosphere secular evolution. Tectonophysics 416, 245-277.
Bachmann, O. and Bergantz, G.W., 2004. On the Origin of Crystal-poor Rhyolites: Extracted from Batholithic Crystal Mushes. Journal of Petrology 45(8), 1565-1582.
Bachmann, O. and Bergantz, G.W., 2008. Rhyolites and their source mushes across tectonic settings. Journal of Petrology 49 (12), 2277-2285.
Bailey, D. K., 1983. The chemical and thermal evolution of rifts. Tectonophysics 94, 585-597.
Barbuena, D., Oliveira, E.P., Zincone, S.A., 2016. Estudos de proveniência dos quartzitos do greenstone belt Mundo Novo (BA) e implicações tectono-estratigráficas. In Anais 48º Congresso Brasileiro de Geologia, Porto Alegre.
Beard, J.S., Lofgren, G.E., 1991. Dehydration melting and water-saturated melting of basaltic and andesitic greenstones and amphibolites at 1, 3 and 6.9 kb. Journal of Petrology 32, 465–501.
Bédard, J. H., 2006. A catalytic delamination-driven model for coupled genesis of Archean crust and subcontinental lithospheric mantle: Geochimica et Cosmochimica Acta 70, 1188–1214.
Bédard, J. H., Harris, L. B., Thurston, P. C., 2013. The hunting of the snArc. Precambrian Research 229, 20-48.
Bégué, F., Deering, C. D., Gravley, D. M., Kennedy, B. M., Chambefort, I., Gualda, G. A. R., Bachmann, O., 2014. Extraction, storage and eruption of multiple isolated magma batches in the paired Mamaku and Ohakuri eruption, Taupo Volcanic Zone, New Zealand. Journal of Petrology 55(8), 1653-1684.
Belousova, E. A., Griffin, W. L., O'Reilly, S. Y., 2006. Zircon crystal morphology, trace element signatures and Hf isotope composition as a tool for petrogenetic modelling: examples from Eastern Australian granitoids. Journal of Petrology 47(2), 329-353.
Bogaerts, M., Scaillet, B. VanderAuwera, J., 2006. Phase equilibria of the Lyngdal granodiorite (Norway): Implications for the origin of metaluminous ferroan granitoids. Journal of Petrology 47, 2405-2431
Bouvier, A., Vervoort, J. D., Patchett, P. J., 2008. The Lu–Hf and Sm–Nd isotopic composition of CHUR: constraints from unequilibrated chondrites and implications for the bulk composition of terrestrial planets. Earth and Planetary Science Letters 273(1), 48-57.
Bryan, S.E., Ernst, R.E., 2008. Revised definition of Large Igneous Provinces (LIPs). Earth-Science Reviews 86, 175-202.
Bryan, S.E., Ferrari, L. 2013. Large Igneous Provinces and Silicic Large Igneous Provinces: progress in our understanding over the last 25 years. Geological Society of America Bulletin 125, 1053–1078.
Bryan, S.E., Constantine, A.E., Stephens, C.J., Ewart, A., Schön, R.W., and Parianos, J., 1997. Early Cretaceous volcano-sedimentary successions along the eastern Australian continental margin: Implications for the break-up of eastern Gondwana. Earth and Planetary Science Letters 153, p. 85–102.
Bryan, S.E., Cook, A.G., Allen, C.M., Siegel, S., Purdy, D., Greentree, J., Uysal, I.T., 2012. Early-mid Cretaceous tectonic evolution of eastern Gondwana: From silicic LIP magmatism to continental rupture. Episodes 35, 142–152.
Bryan, S.E., 2007. Silicic large igneous provinces: Episodes 30, 20–31.
Bryan, S.E., Riley, T.R., Jerram, D.A., Leat, P.T., Stephens, C.J., 2002. Silicic volcanism: An under-valued component of large igneous provinces and volcanic rifted margins, in Menzies, M.A., Klemperer, S.L., Ebinger, C.J., and Baker, J., eds., Magmatic Rifted Margins: Geological Society of America Special Paper 362, 99–120.
Bryan, S.E., Ferrari, L., Reiners, P.W., Allen, C.M., Petrone, C.M., Ramos Rosique, A., and Campbell, I.H., 2008. New insights into crustal contributions to large volume rhyolite generation at the mid-Tertiary Sierra Madre ccidental Province, Mexico, revealed by U-Pb geochronology. Journal of Petrology, 47–77.
Cawood, P.A., Hawkesworth, C.J., Dhuime, B., 2013. The continental record and the generation of continental crust. Geological Society of America Bulletin 125, 14-32.
Campbell, I.H., 2005. Large igneous provinces and the mantle plume hypothesis: Elements 5, 265–269.
Condie, K. C., Bickford, M. E., Aster, R. C., Belousova, E., Scholl, D. W., 2011. Episodic zircon ages, Hf isotopic composition, and the preservation rate of continental crust. Geological Society of America Bulletin 123(5-6), 951-957.
Condie, K. C., 2014. How to make a continent: thirty-five years of TTG research. In Evolution of Archean Crust and Early Life, 179-193. Springer Netherlands.
Condie, K., 2015. Changing tectonic settings through time: indiscriminate use of geochemical discriminant diagrams. Precambrian Research 266, 587-591.
Condie, K., 2016. Earth as an evolving planetary system. Academic Press.
De Wit, M. J., de Ronde, C. E., Tredoux, M., Roering, C., Hart, R. J., Armstrong, R. A., Hart, R. A., 1992. Formation of an Archaean continent. Nature 357, 553-562.
Dhuime, B., Wuestefeld, A., Hawkesworth, C. J. 2015. Emergence of modern continental crust about 3 billion years ago. Nature Geoscience 8(7), 552-555.
Drew, D. L., Bindeman, I. N., Watts, K. E., Schmitt, A. K., Fu, B., McCurry, M., 2013. Crustal-scale recycling in caldera complexes and rift zones along the Yellowstone hotspot track: O and Hf isotopic evidence in diverse zircons from voluminous rhyolites of the Picabo volcanic field, Idaho. Earth and Planetary Science Letters 381, 63-77.
Dufek, J., Bachmann, O., 2010. Quantum magmatism: Magmatic compositional gaps generated by melt-crystal dynamics. Geology 38(8), 687-690.
Eby, G.N., 1992. Chemical subdivision of the A-type granitoids: petrogenetic and tectonic implications. Geology 20, 641–644.
Ellis, B. S., Bachmann, O., Wolff, J. A., 2014. Cumulate fragments in silicic ignimbrites: The case of the Snake River Plain. Geology 42(5), 431-434.
Ernst, R.E. 2014. Large Igneous Provinces. Cambridge University Press, 653 p.
Ewart, A., Schön, R.W., Chappell, B.W., 1992. The Cretaceous volcanic–plutonic province of the central Queensland (Australia) coast: A rift related “calcalkaline” province. Transactions of the Royal Society of Edinburgh–Earth Sciences 83, 327–345.
Friend, C. R., Nutman, A. P., 2005. Complex 3670–3500 Ma orogenic episodes superimposed on juvenile crust accreted between 3850 and 3690 Ma, Itsaq Gneiss Complex, southern West Greenland. The Journal of geology 113(4), 375-397.
Frost, B.R., Barnes, C.G., Collins, W.J., Arculus, R.J., Ellis, D.J., Frost, C.D., 2001. A geochemical classification for granitic rocks. Journal of Petrology 42, 2033-2048.
Frost, C.D., Frost, B.R., 2011. On ferroan (A-type) granitoids: their compositional variability and modes of origin. Journal of Petrology 52, 39–53.
Gelman, S.E., Deering, C.D., Bachmann, O., Huber, C., Guiterrez, F.J., 2014. Identifying the crystal graveyard remaining after large silicic eruptions. Earth Planetary Science Letters 403, 299–306.
Gerdes, A., Zeh, A., 2009. Zircon formation versus zircon alteration - New insights from combined U-Pb and Lu-Hf in-situ LA-ICP-MS analyses, and consequences for the interpretation of Archean zircon from the Central Zone of the Limpopo Belt. Chememical Geology 261, 230–243.
Gerya, T., 2014. Precambrian geodynamics: Concepts and models. Gondwana Research 25(2), 442-463.
Graeter, K. A., Beane, R. J., Deering, C. D., Gravley, D., Bachmann, O., 2015. Formation of rhyolite at the Okataina Volcanic Complex, New Zealand: New insights from analysis of quartz clusters in plutonic lithics. American Mineralogist 100(8-9), 1778-1789.
Grove, T.L., Till, C.B., Krawczynski, M.J., 2012. The role of H2O in subduction zone magmatism. Annual Review of Earth and Planetary Sciences 40, 413–439.
Guitreau, M., Blichert-Toft, J., Martin, H., Mojzsis, S.J., Albarède, F., 2012. Hafnium isotope evidence from Archean granitic rocks for deep-mantle origin of continental crust. Earth and Planetary Science Letters 337, 211–223.
Hanson, R. E., Puckett, R. E., Keller, G. R., Brueseke, M. E., Bulen, C. L., Mertzman, S. A., Finegan, S.A., McCleery, D. A. 2013. Intraplate magmatism related to opening of the southern Iapetus Ocean: Cambrian Wichita igneous province in the Southern Oklahoma rift zone. Lithos 174, 57-70.
Harris, N.B.W., Pearce, J.A., Tindle, A.G., 1986. Geochemical characteristics of collision-zone magmatism. In: Coward M P, Ries A C (eds) Collision Tectonics. Geological Society London Special Publication 19, 67-81.
Hawkesworth, C., Cawood, P., Kemp, A., Storey, C., Dhuime, B., 2009. Geochemistry: A matter of preservation. Science 323, 49–50.
Hawkesworth, C., Dhuime, B., Pietranik, A., Cawood, P., Kemp, T., Storey, C., 2010. The generation and evolution of the continental crust: Journal of Geological Society of London 167, 229–248.
Hawkesworth, C., Cawood, P., Dhuime, B., 2013. Continental growth and the crustal record. Tectonophysics 609, 651–660.
Helz, R.T., 1976. Phase relations in basalts in their melting range at P(H2O)=5 kb. Part II: melt compositions. Journal of Petrology 14(2), 249-302.
Hertogen, J., Gijbels, R., 1976. Calculation of trace element fractionation during partial melting. Geochimica et Cosmochimica Acta 40(3), 313-322.
Hessler, A. M., Lowe, D. R., 2006. Weathering and sediment generation in the Archean: an integrated study of the evolution of siliciclastic sedimentary rocks of the 3.2 Ga Moodies Group, Barberton Greenstone Belt, South Africa. Precambrian Research 151(3), 185-210.
Hoffmann, J.E., Nagel, T.J., Münker, C., Naeraa, T., Rosing, M.T., 2014. Constraining the process of Eoarchean TTG formation in the Itsaq Gneiss Complex, southern West Greenland. Earth and Planetary Science Letters 388, 374-386.
Hoffmann, J.E., Kröner, A., Hegner, E., Viehmann, S., Xie, H., Iaccheri, L.M., Schneider, K.P., Hofmann, A., Wong, J., Geng, H., Yang, J., 2016. Source composition, fractional crystallization and magma mixingprocesses in the 3.48–3.43 Ga Tsawela tonalite suite (Ancient GneissComplex, Swaziland): Implications for Palaeoarchaean geodynamics. Precambrian Research 276, 43-66.
Huang, H. H., Lin, F. C., Schmandt, B., Farrell, J., Smith, R. B., Tsai, V. C., 2015. The Yellowstone magmatic system from the mantle plume to the upper crust. Science, 348(6236), 773-776.
Johnson, T. E., Brown, M., Kaus, B. J., VanTongeren, J. A., 2013. Delamination and recycling of Archaean crust caused by gravitational instabilities. Nature Geoscience 7(1), 47-52.
Keller, C. B., Schoene, B., Barboni, M., Samperton, K. M., Husson, J. M., 2015. Volcanic-plutonic parity and the differentiation of the continental crust. Nature 523(7560), 301-307.
Kemp, A.I.S., Hawkesworth, C.J., Paterson, B.A., Foster, G.L., Kinny, P.D., Whitehouse, M.J., Maas, R., E, M.F., 2008. Exploring the plutonic- volcanic link: a zircon U–Pb, Lu–Hf and O isotope study of paired volcanic and granitic units from southeastern Australia. Transactions of the Royal Society of Edinburgh 97, 337–355.
Kohler, E. A., Anhaeusser, C. R. 2002. Geology and geodynamic setting of Archaean silicic metavolcaniclastic rocks of the Bien Venue Formation, Fig Tree Group, northeast Barberton greenstone belt, South Africa. Precambrian Research 116(3), 199-235.
Kröner, A., Hoffmann, J.E., Xie, H., Wu, F., Münker, C., Hegner, E., Wong, J., Wan, Y., Liu, D., 2013. Generation of early Archaean felsic greenstone volcanic rocks through crustal melting in the Kaapvaal craton, southern Africa. Earth and Planetary Science Letters 381, 188–197.
Lahitte, P., Gillot, P., Courtillot,V., 2003. Silicic central volcanoes as precursors to rift propagation: The Afar case. Earth and Planetary Science Letters 207,103-116.
Laurent, O., Paquette, J.L., Martin, H., Doucelance, R., Moyen, J.-F., 2013. LA-ICP-MS dating of zircons from Meso- and Neoarchean granitoids of the Pietersburg block (South Africa): Crustal evolution at the northern margin of the Kaapvaal craton. Precambrian Research 230, 209–226.
Laurent, O., Martin, H., Moyen, J. F., Doucelance, R. 2014a. The diversity and evolution of late-Archean granitoids: Evidence for the onset of “modern-style” plate tectonics between 3.0 and 2.5 Ga. Lithos 205, 208-235.
Laurent, O., Rapopo,M., Stevens, G.,Moyen, J.F., Martin, H., Doucelance, R., Bosq, C., 2014b. Contrasting petrogenesis of Mg–K and Fe–K granitoids and implications for post- collisionalmagmatism: a case study from the late-Archean Matok pluton (Pietersburg block, South Africa). Lithos 196–197, 131–149.
Laurent, O., Zeh, A., 2015. A linear Hf isotope-age array despite different granitoid sources and complex Archean geodynamics: Example from the Pietersburg block (South Africa). Earth and Planetary Science Letters 430, 326–338.
Lee, C. T. A., Bachmann, O., 2014. How important is the role of crystal fractionation in making intermediate magmas? Insights from Zr and P systematics. Earth and Planetary Science Letters 393, 266-274.
Lipman, P. W., Bachmann, O., 2015. Ignimbrites to batholiths: Integrating perspectives from geological, geophysical, and geochronological data. Geosphere 11(3), 705-743.
Lowe, D. R., Tice, M. M., 2004. Geologic evidence for Archean atmospheric and climatic evolution: Fluctuating levels of CO2, CH4, and O2 with an overriding tectonic control. Geology 32(6), 493-496.
Loureiro, H.S.C., Santos, R.A., 1991. Estratigra?a: Folha Mundo Novo. In: Loureiro H.S.C. (org.), Mundo Novo, folha SC. 24 Y D IV: Estado da Bahia, texto explicativo. Brasília: DNPM. (Programa Levantamentos Geológicos Básicos do Brasil). Convênio DNPM-CPRM, p. 18–21.
Magee, C. W.; Palin, J. M.; Taylor, W. R., 2001. Laser ICP-MS U/Pb analyses of detrital zircons from Proterozoic sediments in Bahia state, Brazil; implications for the evolution of the São Francisco craton prior to 3.3 Ga. 11th Goldschmidt Conference.
Marchesin, W.F., 2015. Geologia, geoquímica e geocronologia do domo da Serra dos Meiras, Bloco Gavião, Bahia. Master dissertation. Universidade Estadual de Campinas.
Marinho, M.M., Vidal, P., Alibert, C., Barbosa, J.S.F., Sabaté P., 1994. Geochronology of the Jequié–Itabuna granulitic belt and of the Contendas–Mirante volcano-sedimentary belt. Boletim de Instituto de Geociências, Universidade de São Paulo, Publicação especial 17, 73–96.
Martel, C., Pichavant, M., Holtz, F., Scaillet, B., Bourdier, J. L., Traineau, H. 1999. Effects of f O2 and H2O on andesite phase relations between 2 and 4 kbar. Journal of Geophysical Research: Solid Earth (1978–2012), 104(B12), 29453-29470.
Martin, E., Sigmarsson, O., 2007. Crustal thermal state and origin of silicic magma in Iceland: the case of Torfajökull, Ljósufjöll and Snæfellsjökull volcanoes. Contributions to Mineralogy and Petrology, 153(5) 593-605.
Martin, H., Peucat, J.J., Sabaté, P., Cunha, J.C., 1997. Crustal evolution in the early Archean of South America: example of the Sete Voltas Massif, Bahia State, Brazil. Precambrian Research 82, 35-62.
Martin, H., Smithies, R. H., Rapp, R., Moyen, J. F., Champion, D., 2005. An overview of adakite, tonalite–trondhjemite–granodiorite (TTG), and sanukitoid: relationships and some implications for crustal evolution. Lithos 79(1), 1-24.
Martin, H., Moyen, J. F., Guitreau, M., Blichert-Toft, J., Le Pennec, J. L., 2014. Why Archaean TTG cannot be generated by MORB melting in subduction zones. Lithos 198, 1-13.
Mascarenhas, J.F., Silva, E.F.A., 1994. Greenstone belt de Mundo Novo: caracterização e implicações metalogenéticas no Cráton do São Francisco. Série Arquivos Abertos 5, 1-32.
Mascarenhas J.F., Ledru P., Souza S.L., Conceição Filho V.M., Melo L.F.A., Lorenzo C.L. Milési J.P. 1998. Geologia e recursos minerais do Grupo Jacobina e da parte sul do Greenstone Belt de Mundo Novo. Série Arquivos Abertos 13, 55p.
McDonough,W.F., Sun, S., 1995. The composition of the Earth. Chemical Geology 120, 223–253.
Middlemost, E. A., 1994. Naming materials in the magma/igneous rock system. Earth-Science Reviews 37(3), 215-224.
Moyen, J.F., Martin, H., 2012. Forty years of TTG research. Lithos 148, 312–336.
Moyen, J. F., 2011. The composite Archaean grey gneisses: petrological significance, and evidence for a non-unique tectonic setting for Archaean crustal growth. Lithos 123(1), 21-36.
Nash, B. P., Perkins, M. E., Christensen, J. N., Lee, D. C., Halliday, A. N., 2006. The Yellowstone hotspot in space and time: Nd and Hf isotopes in silicic magmas. Earth and Planetary Science Letters 247(1), 143-156.
Nutman, A.P., Cordani, U.G., 1993. SHRIMP U–Pb zircon geochronology of Archean granitoids from the Contendas–Mirante area of the São Francisco Craton, Bahia, Brazil. Precambrian Research 163, 179-188.
Nutman, A.P., Cordani, U.G., Sabaté, P., 1994. SHRIMP U-Pb ages of detrital zircons from the early Proterozoic Contendas-Mirante supracrustal belt, Francisco Craton, Bahia, Brazil. Journal of South American Earth Sciences 7, 109-114.
Nutman, A. P., Bridgwater, D., Fryer, B. J., 1984. The iron-rich suite from the Amîtsoq gneisses of southern West Greenland: early Archaean plutonic rocks of mixed crustal and mantle origin. Contributions to Mineralogy and Petrology 87(1), 24-34.
Nutman, A. P., McGregor, V. R., Friend, C. R., Bennett, V. C., Kinny, P. D., 1996. The Itsaq gneiss complex of southern West Greenland; the world's most extensive record of early crustal evolution (3900-3600 Ma). Precambrian Research 78(1), 1-39.
O'Connor, J.T., 1965. A Classification for Quartz-rich Igneous Rocks Based on Feldspar Ratios. US Geological Survey professional paper 525-B, pp. 79–84.
Paquette, J.L., Barbosa, J.S.F., Rohais, S., Cruz, S.C.P., Goncalves, P., Peucat, J.-J., Leal, Â.B.M., Santos-Pinto, M., Martin, H., 2015. The geological roots of South America: 4.1Ga and 3.7Ga zircon crystals discovered in N.E. Brazil and N.W. Argentina. Precambrian Research 271, 49–55.
Pankhurst, R.J., Rapela, C.R., 1995. Production of Jurassic rhyolite by anatexis of the lower crust of Patagonia. Earth and Planetary Science Letters 134, 23–36.
Pearce, J.A., 1982. Trace element characteristics of lavas from destructive plate boundaries. In: Thorpe, R.S. (Ed.), Andesites.Wiley, New York, pp. 525–548.
Pearce, J.A., Lippard, S.J., Roberts, S., 1984. Characteristics and tectonic significance of supra-subduction zone ophiolites. Geological Society, London, Special Publications 16(1), 77-94.
Pearson, W., Macêdo, P.M., Rúbio, A., Lorenzo, C.L., Karpeta, P., 2005. Geology and gold mineralization of the Jacobina Mine and Bahia Gold Belt, Bahia, Brazil and comparison to Tarkwa and Witwatersrand. In: Proceedings, Geological Society of Nevada Symposium, vol. 1, Reno, Nevada, May 2005, pp. 757–786.
Peucat, J.J., Mascarenhas, J.F., Barbosa, J.S., Souza, F.S., Marinho, M.M., Fanning, C.M., Leite C.M.M., 2002. 3.3 Ga SHRIMP U–Pb zircon age of a felsic metavolcanic rock from the Mundo Novo greenstone belt in the São Francisco craton, Bahia (NE Brazil). Journal of South American Earth Sciences 15, 363–373.
Reimink, J. R., Chacko, T., Stern, R. A., Heaman, L. M., 2014. Earths earliest evolved crust generated in an Iceland-like setting. Nature Geoscience 7(7), 529-533.
Riley, T.R., Leat, P.T., Pankhurst, R.J., Harris, C., 2001. Origins of large volume rhyolitic volcanism in the Antarctic Peninsula and Patagonia by crustal melting. Journal of Petrology 42, 1043–1065.
Rudnick, R.L., 1995. Making continental crust. Nature 378, p. 571–578.
Santos-Pinto, M.A.S., Peucat, J.J., Martin H., Sabaté P., 1998. Recycling of the Archaean continental crust: the case study of the Gavião Block, Bahia, Brazil. Journal of South American Earth Sciences 5, 487-498.
Santos-Pinto, M.A.S., Peucat, J.J., Martin, H., Barbosa, J.S.F, Fanning, C.M., Cocherie, A., Paquette, J.L., 2012. Journal of South American Earth Sciences 40, 129-142.
Scherer, E., Münker, C., and Mezger, K., 2001, Calibration of the lutetium-hafnium clock: Science 293, 683-687.
Shand, S.J., 1943. Eruptive Rocks. Their Genesis, Composition, Classification, and Their Relation to Ore-Deposits with a Chapter on Meteorite. John Wiley & Sons, New York, 488 pp.
Simakin, A. G., Bindeman, I. N., 2012. Remelting in caldera and rift environments and the genesis of hot, “recycled” rhyolites. Earth and Planetary Science Letters 337, 224-235.
Sisson, T.W., Ratajeski, K., Hankins, W.B., Glazner, A.F., 2005. Voluminous granitic magmas from common basaltic sources. Contributions to Mineralogy and Petrology 148, 635–661.
Sizova, E., Gerya, T., Stüwe, K., Brown, M. 2015. Generation of felsic crust in the Archean: A geodynamic modeling perspective. Precambrian Research 271, 198-224.
Smithies, R. H., 2000. The Archaean tonalite–trondhjemite–granodiorite (TTG) series is not an analogue of Cenozoic adakite. Earth and Planetary Science Letters 182(1), 115-125.
Smithies, R. H., Champion, D.C., Cassidy, K. F., 2003. Formation of Earth’s early Archaean continental crust. Precambrian Research, 127, 89–101.
Smithies, R.H., Champion, D.C., Van Kranendonk, M.J., 2007. The oldest well-preserved felsic volcanic rocks on Earth: geochemical clues to the early evolution of the Pilbara supergroup and implications for the growth of a Paleoarchean protocontinent. In: Van Kranendonk, M.J., Smithies, R.H., Bennett, V.C. (Eds.), Earth's Oldest Rocks. Elsevier, pp. 339-367.
Smithies, R.H., Champion, D.C., Van Kranendonk, M.J., 2009. Formation of Paleoarchean crust through infracrustal melting of enriched basalt. Earth and Planetary Science Letters 281, 298–306.
Söderlund, U., Patchett, P.J., Vervoort, J.D., Isachsen, C.E., 2004. The 176Lu decay constant determined by Lu-Hf and U-Pb isotope systematics of Precambrian mafic intrusions. Earth and Planetary Science Letters 219, 311–324.
Tang, M., Wang, X.L., Shu, X.J., Wang, D., Yang, T., Gopon, P., 2014. Hafnium isotopic heterogeneity in zircons from granitic rocks: Geochemical evaluation and modeling of “zircon effect” in crustal anatexis. Earth and Planetary Science Letters 389, 188–199.
Tatsumi, Y., Suzuki, T., 2009. Tholeiitic vs calc-alkalic differentiation and evolution of arc crust: Constraints from melting experiments on a basalt from the Izu-Bonin- Mariana Arc. Journal of Petrology 50(8), 1575-1603.
Teles, G., Chemale, F., Oliveira, C.G., 2015. Paleoarchean record of the detrital pyrite-bearing, Jacobina Au-U deposits, Bahia, Brazil. Precambrian Research 256, 289-313.
Thybo, H., Artemieva, I. M. 2013. Moho and magmatic underplating in continental lithosphere. Tectonophysics 609, 605-619.
Umhoefer, P.J., 2011, Why did the southern Gulf of California rupture so rapidly? Oblique divergence across hot, weak lithosphere along a tectonically active margin: GSA Today, v. 21, no. 11, p. 4–10.
Van Kranendonk, M. J., Smithies, R. H., Griffin, W. L., Huston, D. L., Hickman, A. H., Champion, D. C., Pirajno, F., 2014. Making it thick: a volcanic plateau origin of Palaeoarchean continental lithosphere of the Pilbara and Kaapvaal cratons. Geological Society, London, Special Publications 389(1), 83-111.
Van Kranendonk, M. J., 2010. Two types of archean continental crust: plume and plate tectonics on early earth. American Journal of Science 310, 1187-1209.
Van Thienen P., Van den Berg A.P., Vlaar N.J., 2004. Production and recycling of oceanic crust in the early Earth. Tectonophysics 386, 41-65.
Verma, S.K., Pandarinath, K., Verma, S.P., 2012. Statistical evaluation of tectonomagmatic discrimination diagrams for granitic rocks and proposal of new discriminant-function based multi-dimensional diagrams for acid rocks. International Geology Review 54, 325-347.
Verma, S. P., Pandarinath, K., Verma, S. K., Agrawal, S., 2013. Fifteen new discriminant-function-based multi-dimensional robust diagrams for acid rocks and their application to Precambrian rocks. Lithos 168, 113-123.
Whalen, J.B., Currie, K.L., Chappell, B.W., 1987. A-Type granites: geochemical characteristics, discrimination and petrogenesis. Contributions to Mineralogy and Petrology 95, 407-419.
Willbold, M., Hegner, E., Stracke, A., Rocholl, A., 2009. Continental geochemical signatures in dacites from Iceland and implications for models of early Archaean crust formation. Earth and Planetary Science Letters 279, 44–52.
Winchester, J. A., Floyd, P. A., 1977. Geochemical discrimination of different magma series and their differentiation products using immobile elements. Chemical Geology 20, 325-343.
Zegers, T.E., van Keken, P.E., 2001. Middle Archean continent formation by crustal delamination. Geology 29, 1083–1086.
Ziegler, P.A., Cloetingh, S., 2004. Dynamic processes controlling evolution of rifted basins. Earth-Science Reviews 64, 1–50.
Zincone, S. A., Oliveira, E. P., Laurent, O., Zhang, H., Zhai, M. 2016. 3.30 Ga high-silica intraplate volcanic–plutonic system of the Gavião Block, São Francisco Craton, Brazil: Evidence of an intracontinental rift following the creation of insulating continental crust. Lithos, 266, 414-434.
Zincone, S.A., Oliveira, E.P. Field and Geochronological evidence for origin of the Contendas-Mirante Supracrustal Belt, São Francisco Craton, Brazil, as a Paleoproterozoic foreland basin. In review at Precambrian Research.
Zincone, S.A. 2016. Evolution of the Contendas-Mirante supracrustal sequence and Basement: implications for Paleoarchean to Paleoproterozoic tectonic in the northeast São Francisco craton. Doctoral Thesis. University of Campinas.