Figure 1
Locality map for the Cretaceous to Early Cenozoic felsic alkaline intrusive bodies of the state of Rio de Janeiro, modified from Sichel et al. (2012Sichel SE, Motoki A, Iwanuch W, Vargas T, Aires JR, Melo DP, Motoki KF, Balmant A and Rodrigues JG. 2012. Fractionation crystallization and continental crust assimilation by the felsic alkaline rock magmas of the State of Rio de Janeiro, Brazil. Anuário do IGEO - UFRJ35(2): 84-104.): a) Alkaline magmatic alignments of Serra do Mar province and Vitória-Trindade Chain; b) Felsic alkaline intrusive bodies of the state of Rio de Janeiro. The subaqueous pyroclastic flows of the São Mateus Volcanic Province follow that specified by Novais et al. (2007Novais LCC, Zelenka T, Szatmari P, Motoki A, Aires JR and Tagliari CV. 2007. Ocorrência de rochas vulcânicas ignimbríticas na porção norte da Bacia do Espírito Santo: evolução do modelo tectono-sedimentar. Bol Geoc Petr16(1): 139-156.). N.A.: Not analyzed.
Figure 2
Geochemical classification diagrams for felsic alkaline rocks of the state of Rio de Janeiro: a) Na2O+K2O vs. SiO2 (wt%) diagram of Le Bas et al. (1986Le Bas MJ, Le Maitre RW, Streckeisen A and Zanettin B. 1986. A Chemical Classification of Volcanic. Rocks based on the Total-Alkali-Silica Diagram. J Petrol27: 745-750.); b) Na2O vs. K2O wt% of Middlemost (1975Middlemost EAK. 1975. The basalt clan. Earth-Sci Rev 11: 337-364.); c) Alkali-alumina saturation diagram of Maniar and Piccoli (1989Maniar PD and Piccoli PM. 1989. Tectonic discrimination of granitoids. Geol Soc Am Bull 101: 635-64.). The data are originated fromValença (1980Valença JG. 1980. Geology, petrography and petrogenesis of some alkaline igneous complexes of Rio de Janeiro State, Brazil. Thesis, Doctor in Geosciences. West Ontario University, London, Ontario, Canada, 247 p.), Motoki et al. (2010Motoki A, Sichel SE, Vargas T, Aires JR, Iwanuch W, Mello SLM, Motoki KF, Silva S, Balmant A and Gonçalves J. 2010. Geochemical evolution of the felsic alkaline rocks of Tanguá, Rio Bonito, and Itaúna intrusive bodies, State of Rio de Janeiro, Brazil. Geociências29(3): 291-310., 2013Motoki A, Araújo AL, Sichel SE, Motoki KF and Silva S. 2013. Nepheline syenite magma differentiation process by continental crustal assimilation for the Cabo Frio Island intrusive complex, State of Rio de Janeiro, Brazil. Geociências32(2): 195-218.), and Sichel et al. (2012Sichel SE, Motoki A, Iwanuch W, Vargas T, Aires JR, Melo DP, Motoki KF, Balmant A and Rodrigues JG. 2012. Fractionation crystallization and continental crust assimilation by the felsic alkaline rock magmas of the State of Rio de Janeiro, Brazil. Anuário do IGEO - UFRJ35(2): 84-104.).
Figure 3
- Projection of the alkaline rocks of state of Rio de Janeiro on the residual diagram of Norm quartz, nepheline, and kaliophilite (Hamilton and MacKenzie 1960Hamilton DL and MacKenzie WS. 1960. Nepheline solid solution in the system NaAlSiO4-KAlSiO4-SiO. J Petrol1: 56-72.) and geochemical evolution of the nepheline syenite magma, modified fromSichel et al. (2012Sichel SE, Motoki A, Iwanuch W, Vargas T, Aires JR, Melo DP, Motoki KF, Balmant A and Rodrigues JG. 2012. Fractionation crystallization and continental crust assimilation by the felsic alkaline rock magmas of the State of Rio de Janeiro, Brazil. Anuário do IGEO - UFRJ35(2): 84-104.).
Figure 4
SSI (silica saturation index; Motoki et al. 2010Motoki A, Sichel SE, Vargas T, Aires JR, Iwanuch W, Mello SLM, Motoki KF, Silva S, Balmant A and Gonçalves J. 2010. Geochemical evolution of the felsic alkaline rocks of Tanguá, Rio Bonito, and Itaúna intrusive bodies, State of Rio de Janeiro, Brazil. Geociências29(3): 291-310.) vs. (Na+K)/Al mol. diagram for the felsic alkaline rocks of the state of Rio de Janeiro, modified from Sichel et al. (2012Sichel SE, Motoki A, Iwanuch W, Vargas T, Aires JR, Melo DP, Motoki KF, Balmant A and Rodrigues JG. 2012. Fractionation crystallization and continental crust assimilation by the felsic alkaline rock magmas of the State of Rio de Janeiro, Brazil. Anuário do IGEO - UFRJ35(2): 84-104.). SSI=1000(SiO2/60,0835-Al2O3/101,9601-5(Na2O/61,9785+K2O/94,1956)-CaO/56,077-MgO/40,304-MnO/70,937-FeO/71,844+2Fe2O3/159,687) wt%.
Figure 5
- Classification of the felsic alkaline rocks of the state of Rio de Janeiro based on immobile elements (Winchester and Floyd 1977Winchester JA and Floyd PA. 1977. Geochemical discrimination of different magma series and their differentiation products using immobile elements. Chem Geol20: 325-343.): a) Nb/Y vs. Zr/TiO2; b) Zr/TiO2 vs. SiO2; c) Ce vs. Zr/TiO2; d) Ga vs. Zr/TiO2. The geochemical data follow that of Valença (1980Valença JG. 1980. Geology, petrography and petrogenesis of some alkaline igneous complexes of Rio de Janeiro State, Brazil. Thesis, Doctor in Geosciences. West Ontario University, London, Ontario, Canada, 247 p.), Motoki et al. (2010Motoki A, Sichel SE, Vargas T, Aires JR, Iwanuch W, Mello SLM, Motoki KF, Silva S, Balmant A and Gonçalves J. 2010. Geochemical evolution of the felsic alkaline rocks of Tanguá, Rio Bonito, and Itaúna intrusive bodies, State of Rio de Janeiro, Brazil. Geociências29(3): 291-310., 2013Motoki A, Araújo AL, Sichel SE, Motoki KF and Silva S. 2013. Nepheline syenite magma differentiation process by continental crustal assimilation for the Cabo Frio Island intrusive complex, State of Rio de Janeiro, Brazil. Geociências32(2): 195-218.), and Sichel et al. (2012Sichel SE, Motoki A, Iwanuch W, Vargas T, Aires JR, Melo DP, Motoki KF, Balmant A and Rodrigues JG. 2012. Fractionation crystallization and continental crust assimilation by the felsic alkaline rock magmas of the State of Rio de Janeiro, Brazil. Anuário do IGEO - UFRJ35(2): 84-104.).
Figure 6
- Tectonic environment discrimination diagrams for the felsic alkaline rocks of the state of Rio de Janeiro after: a) Pearce et al. (1984Pearce JA, Harris NBW and Tindle AG. 1984. Trace element discrimination diagrams for the tectonic interpretation of granitic rocks. J Petrol25: 956-983.), Pearce (1996)Pearce JA. 1996. Sources and settings of granitic rocks. Episodes 19(4): 120-125.; b) Batchelor and Bowden (1985Batchelor RA and Bowden P. 1985. Petrogenetic interpretation of granitic rocks series using multícationic parameters. Chem Geol 48: 43-55. ).
Figure 7
- Variation diagrams based on trace elements for the felsic alkaline rocks of the state of Rio de Janeiro: a) Rb/K mol.; b) Rb/Ba mol.; c) Zr/TiO2 wt. The abscissa K2O/(K2O+Na2O) wt% represents fractionation crystallization grade of felsic minerals.
Figure 8
- Variation of alkali earth elements according to silica saturation index (SSI): a) SSI vs. Sr (ppm); b) SSI vs. Ba (ppm); c) SSI vs. Ba/Sr (ppm ratio).
Figure 9
- Diagrams of LILE vs. HFSE: a) Nb vs. Rb (ppm); b) Nb/Y vs. Rb/K (ppm).
Figure 10
- Normalized rare earth elements for the felsic alkaline rocks of state of Rio de Janeiro: a) Tanguá intrusive complex; b) Rio Bonito intrusive complex; c) Unusual REE patterns; d) GdN/YbN vs. LaN/SmNdiagram. The CI chondrite data are from McDonough and Sun (1995McDonough WF and Sun S. 1995. The composition of the Earth. Chem Geol120: 223-253. ).
Figure 11
(Sm/Sm*)* and Eu/Eu* for the samples of Tanguá and Rio Bonito alkaline complex, state of Rio de Janeiro: a) Definition of (Sm/Sm*)* which represents convexity of REE pattern; b) Total REEs vs. (Sm/Sm*)*; c) Total REEs vs. Eu/Eu*; d) SSI vs. Eu/Eu*.
Figure 12
- Multi-elements spider diagrams for the samples of Tanguá and Rio Bonito intrusive complexes, state of Rio de Janeiro.
Figure 13
- Zr/TiO2 wt ratio variation according to: a) K2O/(K2O+Na2O) wt%; b) (K+Na)/Al mol.; c) silica saturation index (SSI).
Figure 14
- Schematic illustration for the contact zone of the nepheline syenite intrusive bodies and its geochemical interpretations on the diagrams of (Na+K) vs. SSI, SSI vs. Ba, SSI vs. Ba/Sr, and SSI vs. Zr/TiO
2, which are related, respectively, to
Fig. 4, 8b, 8c, and 13c.
