Figure 1.
Geochronological and Tectonic Provinces of the Amazon Craton (Ruiz 2005).
Figure 2.
Maps: (A) Tectonic of S/SW Amazon Craton (modified from Ruiz et al. 2010Ruiz A.S., D'agrella Filho M.S., Sousa M.Z.A., Lima G.A. 2010. Tonian sills and mafic dike swarms of S-SW Amazonian Craton: records of Rodinia Supercontinent breakup? In: The Meeting Of The Americas. Foz do Iguaçu. Abstracts Foz do Iguaçu: The Meeting of the Americas, 2010, v. único.); (B) Rio Apa Terrane (modified from Cordani et al. 2010Cordani U.G., Teixeira W., Tassinari, C.C.G., Ruiz A.S. 2010. The Rio Apa Craton in Mato Grosso do Sul (Brazil) and Northern Paraguay geochronological evolution, correlations and tectonic implications for Rodinia and Gondwana. American Journal of Science, 310:1-43.).
Figure 3.
Geological Map of the Taquaral Granite and the Neoproterozoic and Quaternary sedimentary covers.
Figure 4.
QAP diagram for the rocks from the Taquaral Granite (rock fields according to Le Maitre et al. 2002Le Maitre R.W. 2002. Igneous rocks: a classification and glossary of terms: recommendations of the international union of geological sciences subcommission on the systematics of igneous rocks. Cambridge, Cambridge University Press, 236 p.).
Figure 5.
Macroscopic aspects of the Taquaral Granite: (A) medium-grained, weakly foliated, granodiorite from the gray, medium- to coarse-grained facies; (B) gray, inequigranular medium- to coarse-grained granodiorite from the gray, medium- to coarse-grained facies; (C) coarse-grained, well foliated monzogranite from the pink, coarse-grained facies; (D) reddish-pink inequigranular rock displaying cataclastic bands from the pink, coarsegrained facies; (E) aplite dikes pink in color, up to 15 cm thick, in abrupt and reactive contacts with monzogranite, and inclusions of angular fragments from the monzogranitic host; (F) fi ne-grained aplite of syenogranitic composition from the pink, fi ne-grained facies
Figure 6.
Microphotographs of gray, medium- to coarse-grained facies illustrating: (A) coarse-grained inequigranular texture; (B) plagioclase displaying intensely saussuritized core highlighting normal zoning, being epidote and calcite the main alteration products; (C) Quartz and alkali-feldspar in micrographic texture; (D) perthitic alkalifeldspar in contact with saussuritized plagioclase. Crossed polarizers.
Figure 7.
Microphotographs of pink, coarse-grained facies illustrating: (A) coarse-grained equigranular texture; (B) microcline crystal of 8 mm in diameter. Crossed polarizers.
Figure 8.
Microphotographs of pink, fi ne-grained facies: (A) general aspect displaying predominant equigranular xenomorphic texture and saussuritized plagioclase; (B) Xenomorphic texture in detail consisting of quartz, microcline, and saussuritized plagioclase. Crossed polarizers.
Figure 9.
Field and macroscopic aspects of diabase dikes illustrating: (A) and (B) outcrops in abrupt contact with Taquaral Granite; (C) dark-gray, fi ne-grained rocks in outcrop; (D) Subophitic texture composed of plagioclase laths and mafi c minerals.
Figure 10.
Microphotographs of the Taquaral Granite illustrating F1 deformation products: (A) S1 foliation in monzogranite showing mafi c minerals oriented; (B) mylonite displaying rotated alkali feldspar porphyroclasts in a fi ne-grained groundmass.
Figure 11.
Polar and frequency stereonet of the S1 foliation of Taquaral Granite showing maximum concentration at 287/82.Lower hemisphere.
Figure 12.
Microphotographs of F1 illustrating: (A) Level showing sigmoidal aspect consisting of quartz subgrains and recrystallized feldspars; (B) rotated and dusty alkali feldspar porphyroclast. Crossed polarizers in A and parallel in B.
Figure 13.
Macroscopic features: (A) protocataclasite composed of angular to rounded fragments of granite, dolomitic limestone and diabase varying from 1 to 50 in diameter in a medium- to coarse-grained groundmass; (B) 10 cm-cataclastic band composed of angular to rounded crystals of alkali feldspar and plagioclase on the scale of millimetres to centimetres set in a fi ner-grained groundmass, gray to pink in color.
Figure 14.
Major-element variation Harker diagrams in weight per cent of oxides for the Taquaral Granite rocks
Figure 15.
Diagrams showing representative distribution of the Taquaral Granite analyses: (A) R1-R2 (La Roche 1980La Roche H 1980 . Granites chemistry through multicationic diagrams. Sciences de la Terre, Série Informatique Géologique, 13:65-88.); (B) Q-P (Debon & Le Fort 1983Debon F. & Le Fort P 1983. A chemical mineralogical classification of common plutonic rocks and associations. Trans. R. Soc. Edinburgh: Earth Science, 73:135-149.) fields: (C) Normative An-Ab-Or (O'Connor 1965O'Connor J.T. 1965. A classification for quartz-rich igneous rocks based on feldspar ratios. US Geological Survey, 525B: 79-84., modified by Barker 1979Barker O.B. 1979. A contribution to the geology of the Soutpansberg Group, Waterberg Supergroup, northern Transvaal. M. Sc. Thesis, Witwatersrand Univ., Johannesburg, 116 p.).
Figure 16.
Diagrams showing representative distribuition of the Taquaral Granite analyses: (A) Na2O+K2O-CaO versus SiO2 (Frost et al. 2001Frost B.R., Barnes C.G., Collins W.J., Arculus R.J., Elis D.J., Frost C.D. 2001. A Geochemical Classification for Granitic Rocks. Journal of Petrology, 42:2033-2048.); (B) K2O versus SiO2 (Peccerillo & Taylor 1976Peccerillo R. & Taylor S. R 1976 . Geochemistry of Eocene calc-alkaline volcanic rocks from the Kastamonu area, northern Turkey. Contributions to Mineralogy and Petrology, 58: 63-81.); (C) FeOtot/ (FeOtot+MgO) versus SiO2 (Frost et al. 2001Frost B.R., Barnes C.G., Collins W.J., Arculus R.J., Elis D.J., Frost C.D. 2001. A Geochemical Classification for Granitic Rocks. Journal of Petrology, 42:2033-2048.) and (D) A/ NK versus A/CNK (Maniar & Piccoli 1989Maniar P. D. & Piccoli P.M. 1989. Tectonic discrimination of granitoids. Geological Society American Bulletin, 101:635-643.).
Figure 17.
Diagrams showing representative distribution of the Taquaral Granite analyses: (A) Rb versus Y+Nb (Pearce et al. 1984Pearce J.A., Harris N.B.W., Tindle A.G. 1984. Trace element discrimination diagrams for the tectonic interpretation of granitic rocks. Journal of Petrology, 25(4):956-983.); (B) Hf-Rb/30-Ta*3 (Harris et al. 1986Harris N.B.W., Pearce J.A., Tindle A.G. 1986. Geochemical characteristics of collision-zone magmatism. In: Coward M.P. & Ries, A.C. (eds) Special Publications of Geological Society, London, 19:67-81.).
Figure 18.
Diagrams showing elemental distribution patterns of the Taquaral Granite: (A) Trace elements and K2O normalized to Ocean Ridge Granite values according to Pearce et al (1984)Pearce J.A., Harris N.B.W., Tindle A.G. 1984. Trace element discrimination diagrams for the tectonic interpretation of granitic rocks. Journal of Petrology, 25(4):956-983.; (B) REE normalized to C1 chondrite values (Sun & MacDonough 1989Sun S.S. & MacDonough W.F. 1989. Chemical and isotopic systematics of oceanic basalts: implications for mantle composition and process . Geological Society London, 1:1313-345.).
Figure 19.
Cathodoluminescence imaging image of zircons from sample RM-07: (A) 2.1; (B) 3.1; (C) 4.1; (D) 5.1; (E) 6.1; (F) 7.1; (G) 9.1; (H) 10.1; (I) 11.1; (J) 12.1. This image also illustrates the zircon pits.
Figure 20.
U-Pb Concordia diagram (SHRIMP) of sample RM-07 from the Taquaral Granite showing an upper intercept age at 1861 ± 5.3 Ma which is interpreted as the crystallization age for the granitic body.
Table 1.
Geochronological data available for the granitic rocks from Alumiador Intrusive Suite obtained by SHRIMP U-Pb on zircon, Rb-Sr, Sm-Nd, Ar-Ar and K-Ar.
Table 2.
Chemical data of the Taquaral Granite (major oxides (weight %), minor and trace elements in weight ppm).
Table 3.
SHRIMP U-Pb zircon analyses from sample RM-07.
Table 4.
Sm-Nd Analytical data of the Taquaral Granite.