C-rich marbles from the proterozoic einasleigh metamorphics, Northern Queensland

Four samples of dolomitic marble from the Proterozoic Einasleigh Metamorphics of northern Queensland contain unusually high δ13C (5.1 to 5.9‰ PDB). A hyper-saline depositional and diagenetic environment for these rocks adequately explains the available field and chemical evidence, and the heavy carbon signature

Evolution Of The Northern Segment Of The Itabuna-salvador-curaca Orogen: Chronology Of Oceanic Crust, Continent-continent Collision And Domain Escape [evolução Do Segmento Norte Do Orógeno Itabuna-salvador-curaçá: Cronologia Da Acresçã O De Arcos, Colisão Continental E Escape De Terrenos]

U-Pb and Pb-evaporation zircon ages, together with whole-rock Sm-Nd and Pb-Pb data, are used to unravel the tectonic evolution of the northern segment of the Itabuna-Salvador-Curaçá Orogen, northeastern São Francisco Craton. The results of this geochronologic study indicate that oceanic crust and island arc sequences accreted at 3.3 Ga, forming the Mundo Novo Greenstone Belt, and that between 2.2-2.12 Ga the Rio Itapicuru and Rio Capim Greenstone Belts were formed in a similar fashion. Age data and Nd isotopes also suggest that Andean-type continental margins are likely to have formed in the span of time 3.08-2.98 Ga, giving rise to the TTG belts of Retirolândia and Jacurici river, and to the Caraíba Complex between 2.69 - 2.63 Ga. Around 2109 Ma, continent-continent collision closed the Rio Itapicuru volcano-sedimentary basin, as inferred from the syntectonic emplacement of the Itareru Tonalite between the Rio Itapicuru Greenstone Belt to the east and the banded gneisses of the Serrinha Block to the west. This collision culminated in a major shift from frontal or oblique convergence to orogen-parallel block-escape about 2084 Ma ago and continued at least till 2039 Ma. During this event several elongated granitic and syenitic bodies were emplaced in the continental crust. The Itiúba Syenite, dated at 2084 Ma and stretching over 150 km east of the Caraíba Complex, is an example of one of these intrusive bodies.414153Alves Da Silva, F.C., Chauvet, A., Faure, M., Early Proterozoic orogeny (Transamazonian) and syntectonic granite emplacement in the Rio Itapicuru greenstone belt, Bahia, Brazil (1993) Comptes Rendus de L'Academie des Sciences. Paris II, 316, pp. 1139-1146Barbosa, J.S.F., Síntese do conhecimento sobre a evolução geotectônica das rochas metamórficas arqueanas e paleoproterozóicas do embasamento do Cráton do São Francisco na Bahia (1997) Revista Brasileira de Geociências, 27, pp. 241-256Barbosa, J.S.F., The granulites of the Jequié Complex and Atlantic Mobile Belt, southern Bahia, Brazil - An expression of Archean-Proterozoic plate convergence (1990) Granulites and Crustal Evolution, pp. 195-221. , VIELZEUF, D.VIDAL, P. (eds.) Boston: Kluwer, AcademicBarbosa, J.S.F., Oliveira, E.P., Corrêa Gomes, L.C., Marinho, M.M., Melo, R.C.I., Geologia e Guia de Excursão (2001), WORKSHOP SOBRE O ORÓGENO ITABUNA-SALVADOR-CURAÇÁ, SalvadorBarbosa, J.S.F., Sabaté, P., Geological features and the Paleoproterozoic collision of four Archean crustal segments of the São Francisco Craton, Bahia, Brazil: A syntheis (2002) Anais Da Academia Brasileira de Ciências, 74, pp. 343-359Barrueto, H.R., Petrogênese das intrusões compostas de Teofilândia e Barrocas, Greenstone Belt do Rio Itapicuru, Bahia, Brasil (2002), p. 188. , f. Tese (Doutorado) - Instituto de Geociências, UNICAMPBarrueto, H.R., Oliveira, E.P., Dall' Agnol, R., Trace element and Nd isotope evidence forjuvenile, arc-related granitoids in the southern portion of the Paleoproterozoic Rio Itapicuru Greenstone Belt (RIGB), Bahia, Brazil (1998), p. 520. , CONGRESSO BRASILEIRO DE GEOLOGIA, 40., 1998. Belo Horizonte. Anais. Belo Horizonte: SBGCarvalho, M.J., Geologia e geoquímica do Tonalito-Diorito Itareru, borda ocidental do Greenstone Belt do Rio Itapicuru, Bahia (2001), p. 71. , f. Dissertação (Mestrado) - Instituto de Geociéncias, UNICAMP, CampinasCarvalho, M.J., Oliveira, E.P., The Itareru Tonalite: An elongated, sin-collisional body in the Serrinha Block of the Itabuna-Salvador-Curaçá Orogen. Simpósio Faixas Móveis Proterozóicas (2002), CONGRESSO BRASILEIRO DE GEOLOGIA, 41., 2002. João Pessoa. Anais. João Pessoa: SBGChauvet, A., Guerrot, C., Alves Da Silva, F.C., Faure, M., Géochronologie 207Pb/206Pb et 40Ar/39 Ar des granites paléoproté rozoiques de la ceinture de roches vertes du Rio Iapicuru (Bahia, Brésil) (1997) Comptes Rendus de L'Academie des Sciences. Paris II, 324, pp. 293-300Chauvet, A., Silva, F.C.A., Faure, M., Guerrot, C., Structural evolution of the Paleoproterozoic Rio Itapicuru. granite-greenstone belt (Bahia, Brazil): The role of synkinematic plutons in the regional tectonics (1997) Precambrian Research, 84, pp. 139-162Conceição, H., Sabaté, P., Bonin, B., The Itiúba alkaline syenite massif, Bahia State (Brazil): Mineralogical, geochemical and petrological constraints - Relation to the genesis of rapakivi magmatism (1991) Precambrian Research, 51, pp. 283-314Condie, K., (1997) Plate Tectonics and Crustal Evolution, p. 282. , 4.ed. Butterworth HeinemannCordani, U.G., Sato, K., Nutman, A., Single zircon SHRIMP determination from Archean tonalitic rocks near Uauá, Bahia, Brazil (1999), pp. 27-30. , SOUTH AMERICAN SYMPOSIUM ON ISOTOPE GEOLOGY, 2.,1999. Córdoba, Argentina. Proceedings. Córdoba: Instituto de Geologia y Recursos MineralesCosta, L.A.M., Mascarenhas, J.F., The high-grade metamorphic terrains in the interval Mutuipe-Jequié: Archean and Lower Proterozoic of east-central Bahia (1982), pp. 19-37. , INTERNATIONAL SYMPOSIUM ON ARCHEAN AND EARLY PROTEROZOIC GEOLOGIC EVOLUTION AND METALLOGENESIS, 1982. Salvador, Brazil. Abstracts excursions. Salvador: SecretariaFigueiredo, M.C.H., Geochemical evolution of eastern Bahia, Brazil: A probable Early Proterozoic subduction-related magmatic arc (1989) Journal of South American Earth Sciences, 2 (2), pp. 131-145Figueiredo, M.C.H., Barbosa, J.S.F., Terrenos metamórficos de alto grau do cráton do São Francisco (1993) O Cráton Do São Francisco, pp. 63-83. , DOMINGUEZ, J.M.L. & MISI, A. (Eds.) Salvador: SBG/SGM/CNPqJardim De, S.A.E.F., Archanjo, C.J., Legrand, J.M., Structural and metamorphic history of part of the high-grade terrain in the Curaçá Valley, Bahia, Brazil (1982) Revista Brasileira de Geociéncias, 12, pp. 251-262Kosin, M., Guimarães, J.T., Abram, M.B., (1999), (Orgs.) Folha Aracaju-SW: SC.24-Y. Salvador: CPRM, (Programa Levantamentos Geológicos Básicos do Brasil)Kosin, M., Melo, R.C., Oliveira, E.P., Geologia do Bloco Serrinha e do segmento norte do Orógeno Itabuna-Salvador-Curaçá (2001), 3, p. 19. , BARBOSA, J.S.F, OLIVEIRA, E. P., CORRÊA GOMES, L. C., MARINHO, M. M., MELO, R. C. (eds) In: WORKSHOP SOBRE O ORÓGENO ITABUNA-SALVADOR-CURAÇÁ, 2001 Salvador. CapKosin, M., Melo, R.C., Souza, J.D., Oliveira, E.P., Carvalho, M.J., Leite, C.M.M., Geologia do segmento norte do Orógeno Itabuna-Salvador-Curaçá e guia de excursão Revista Brasileira de Geociências, 33. , (no prelo)Lacerda, C.M.M., Evolução Estrutural e Petrogenética do Domo Granodiorítico de Ambrósio, Greenstone Belt do Rio Itapicuru, Bahia (2000), p. 174. , f. Tese (Doutorado) - Instituto de Geociências, UNICAMPLedru, P., Cocherie, A., Barbosa, J., Johan, V., Onstott, T., Ages du métamorphisme granulitique dans le craton du São Francisco (Brésil). Implications sur la nature de l'orogène transamazonien (1994) Comptes Rendus de L'Academie des Sciences. Paris II, 318, pp. 251-257Ledru, P., Milési, J.P., Johan, V., Sabaté, P., Maluski, H., Foreland basins and gold-bearing conglomerates: A new model for the Jacobina Basin (São Francisco province, Brazil) (1997) Precambrian Research, 86, pp. 155-176Leite, C.M.M., A evolução geodinâmica da orogênese paleoproterozóica nas regiões de Capim Grosso - Jacobian e Pintadas - Mundo Novo (Bahia, Brasil): Metamorfismo, anatexia crustal e tectõnica (2002), p. 412. , f, Tese (Doutorado) - Instituto de Geociências, Universidade Federal da BahiaMartin, H., Sabate, P., Peucat, J.J., Cunha, J., Un segment de croûte continentale d'âge archéen ancient (3.4 milliards d'années): Le massif de Sete Voltas (Bahia, Brésil). Paris II (1991) Comptes Rendus de L'Academie des Sciences, 313, pp. 531-538Martin, H., Peucat, J.J., Sabate, P., Cunha, J., Crustal evolution of the early Archean of South America: Example of the Sete Voltas Massif, Bahia State, Brazil (1997) Precambrian Research, 82, pp. 35-62Mascarenhas, J.F., Silva, E.F.A., Greenstone, Belt de Mundo Novo: Caracterização e implicações metalogenéticas e geotectônicas no Cráton do São Francisco (1994) Série Arquivos Abertos, (5), pp. 1-31Mascarenhas, J.H., Estruturas do tipo greenstone belt no leste da Bahia (1979) Geologia E Recursos Minerais Do Estado Da Bahia, 2, pp. 25-53. , Salvador: SME/COMMello, E.F., Oliveira, E.P., Mcnaughton, N., SHRIMP U-Pb geochronology of Early Precambrian quartzite and its basement (Caldeirão Belt), NE Sao Francisco Craton, Bahia-Brazil (1999), pp. 78-81. , SOUTH AMERICAN SYMPOSIUM ON ISOTOPE GEOLOGY, 2., 1999. Córdoba. Actas. Córdoba: SEGEMARMello, E.F., Lacerda, C.M.M., Oliveira, E.P., Mcnaughton, N., SHRIMP U-Pb geochronology on xenotime and zircon from the Ambrosio dome, Rio Itapicuru Greenstone Belt, Brazil: A major syntectonic granodiorite intrusion (1999), pp. 331-334. , SOUTH AMERICAN SYMPOSIUM ON ISOTOPE GEOLOGY, 2.,1999. Córdoba. Actas. Córdoba: SEGEMARMello, E.F., Xavier, R.P., Mcnaughton, N., Fletcher, I., Lacerda, C.M.M., Oliveira, E.P., Age constraints of felsic intrusions, metamorphism, deformation and gold mineralization in the Paleoproterozoic Rio Itapicuru Greenstone Belt, NE Bahia State, Brazil (2000) General Symposium Stable and Radiogenic Isotopes in Metallogenesis, , INTERNATIONAL GEOLOGICAL CONGRESS, 31., 2000. Rio de Janeiro. Rio de Janeiro, 1 CD-ROMMelo, R.C., Silva, L.C., Fernandes, P.C., Estratigrafia (1991), pp. 23-47. , MELO, R. C. (Org.) Pintadas - Folha SC.24-Y-D-V. Brasilia: CPRM, (Programa de Levantamentos Geológicos Básicos do Brasil)Melo, R.C., Tectônica (1995), pp. 41-50. , MELO, R.C., LOUREIRO, H.S.C.PEREIRA, L.H.M. (Orgs.) Serrinha - Folha SC.24-Y-D. Brasília: CPRM, 1995 (Programa de Levantamentos Geológicos Básicos do Brasil)Mougeot, R., Respaut, J.P., Ledru, P., Milesi, J.P., Johan, V., U-Pb geocronological constraints for the evolution of the Paleoproterozoic Jacobina auriferous basin (São Francisco Province, Bahia, Brazil) (1996), 6, pp. 582-584. , CONGRESSO BRASILEIRO DE GEOLOGIA, 39., 1996. Salvador. Proceedings. Salvador: SBGMusumeci, G., Magmatic belts in accretionary magins, a key for tectonic evolution: The Tonalite Belt of North Vuctoria Land (East Antarctica) (1999) Journal of the Geological Society. London, 156, pp. 177-189Nutman, A.P., Cordani, U.G., SHRIMP U-Pb zircon geochronology of Archean granitoids from the Contendas-Mirante area of the São Francisco Craton, Bahia, Brazil (1993) Precambrian Research, 63, pp. 179-188Oliveira, E.P., Tarney, J., Genesis of the copper-rich Caraiba norite-hypersthenite complex, Brazil (1995) Mineralium Deposita, 30, pp. 351-373Oliveira, E.P., Lafon, J.M., Souza, Z.S., A Paleoproterozoic age for the Rio Capim volcano-plutonic sequence, Bahia, Brazil: Whole-rock Pb-Pb, Pb-evaporation and U-Pb constraints (1998), p. 14. , CONGRESSO, BRASILEIRO DE GEOLOGIA, 40., 1998. Belo Horizonte. Anais. Belo Horizonte: SBGOliveira, E.P., Lafon, J.-M., Souza, Z.S., Archaean-Proterozoic transition in the Uauá Block, NE São Francisco Craton, Brazil: U-Pb, Pb-Pb and Nd isotope constraints (1999), pp. 38-40. , INTERNATIONAL SYMPOSIUM ON TECTONICS OF THE BRAZILIAN GEOLOGICAL SOCIETY, 1999. Lençóis. Abstract Volume. LençóisOliveira, E.P., Souza, Z.S., Corrêa-gomes, L.C., U-Pb dating of deformed mafic dyke and host gneiss: Implications for understanding reworking processes on the western margin of the Archaean Uauá Block, NE São Francisco Craton, Brazil (2000) Revista Brasileira de Geociências, 30, pp. 149-152Oliveira, E.P., Carvalho, M.J., Duarte, M.I.D., Extrusion of the Archaean Uauá Block in the northern segment of the Itabuna-Salvador-Curaçá orogen, Bahia, and implications for diamond prospecting (2001), 35. , SYMPOSIUM ON DIAMOND GEOLOGY, 3., BraziliaOliveira, E.P., Mello, E.F., Mcnaughton, N., Reconnaissance U-Pb geochronology of early Precambrian quartzites from the Caldeirão belt and their basement, NE São Francisco Craton, Bahia, Brazil: Implications for the early evolution of the Palaeoproterozoic Salvador-Curaçá Orogen (2002) Journal of South American Earth Sciences, 15 (3), pp. 284-298Oliveira, E.P., Mello, E.F., Mcnaughton, N., Choudhuri, A., SHRIMP U-Pb age of the basement to the Rio Itapicuru Greenstone Belt, NE São Francisco Craton (2002), p. 522. , CONGRESSO BRASILEIRO GEOLOGIA, 41., 2002. João Pessoa. Anais. João Pessoa: SBG-Núcleo NordesteOliveira, E.P., Carvalho, M.J., Duarte, M.I.M., Extrusion of the Archaean Uauá Block during Palaeoproterozoic continent-continent collision - Northern segment of the Itabuna-Salvador-Curaçá orogen, Bahia (2002), p. 324. , CONGRESSO BRASILEIRO GEOLOGIA, 41., 2002c. Anais. João Pessoa: SBG-Núcleo NordesteGondwana, E.P., Choudhuri, A., Mello, E.F., Mcnaughton, N., SHRIMP U-Pb geochronology of the basement to the Rio Itapicuru granite-greenstone belt, Bahia, Brazil Gondwana Research, , (a submeter)Padilha, A.V., Melo, R.C., Pereira, L.H.M., Sampaio, A.R., Loureiro, H.S.C., Teixeira, L.R., Motta, A.C., Orógeno Curaçá-Ipirá/Uma contribuiç ão à geologia da região centro-nordeste do Estado da Bahia (1990), p. 346. , CONGRESSO BRASILEIRO DE GEOLOGIA, 36., Natal. Boletim de Resumos. Natal: SBGPadilha, A.V., Melo, R.C., Estruturas e tectônica MELO R. C. (org.) Pintadas - Folha SC.24-Y-D-V, Estado da Bahia. Brasília: CPRM (Programa Levantamentos Geológicos Básicos do Brasil)Thexão, M.A.P., Oliveira, E.P., The Lagoa da Vaca complex: An Archaean layered anorthosite body on the western edge of the Uauá Block, Bahia, Brazil (1998) Revista Brasileira de Geociências, 28, pp. 201-208Peucat, J.J., Mascarenhas, J.F., Barbosa, J.S., Souza, F.S., Marinho, M.M., Fanning, C.M., Leite, C.M.M., 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) (2002) Journal South American Earth Sciences, 15, pp. 363-373Rios, D.C., Granitogênese no Núcleo Serrinha, Bahia, Brasil: Geocronologia e litogeoquímica (2002), p. 239. , f. Tese (Doutorado) - Instituto de Geociências, Universidade Federal da BahiaRios, D.C., Conceição, H., Davis, D.W., Marinho, M.M., Rosa, M.L.S., Os cristais de zircão mais velhos da América do Sul (2002), p. 526. , CONGRESSO BRASILEIRO DE GEOLOGIA, 41., 2002. João Pessoa. Anais. João Pessoa: SBGRios, D.C., Davis, D.W., Conceição, H., Macambira, M.J.B., Peixoto, A.A., Cruz Filho, B.E., Oliveira, L.L., Ages of granites of the Serrinha Nucleus, Bahia (Brazil): An overview (2000) Revista Brasileira de Geocii̧ncias, 30, pp. 74-77Rubatto, D., Gebauer, D., Use of cathodoluminescence for U-Pb zircon dating by ion microprobe: Some examples from the Western Alps (2000) Cathodoluminescence in Geosciences, pp. 373-400. , PAGEL, M., BARBIN, V.BLANC, P., OHNENSTETTER, D. (Eds) Springer VerlagSabaté, P., Peucat, J.J., Melo, R.C., Pereira, M., Datação por Pb-evaporação de monozircão em ortognaisse do Complexo Caraíba: Expressão do acrescimento crustal transamazônico do Cinturão Salvador-Curaçá (Cráton do São Francisco, Bahia, Brasil) (1994) Boletim de Resumos Expandidos, 1, pp. 219-220. , CONGRESSO BRASILEIRO DE GEOLOGIA, 38., 1994. Camboriú Camboriú: SBGSantos, R.A., Souza, J.D., Projeto mapas metalogenéticos e de previsão de recursos minerais (1985), p. 12. , Serrinha, folha SC.24-Y-D. Brasília: DNPM/CPRM, Escala 1:250.000Silva, L.C., Mcnaughton, N.J., Melo, R.C., Fletcher, I.R., U-Pb SHRIMP ages in the Itabuna-Caraíba TTG high-grade complex: The first window beyond the Paleoproterozoic overprinting of the eastern Jequié craton, NE Brazil (1997), pp. 282-283. , International symposium on granites and associated mineralizations, 2., 1997. Salvador. Proceedings. Salvador: Sociedade Brasileira de GeologiaSilva, M.G., Geoquímica, geocronologia e isótopos (Sm-Nd e Pb-Pb) da Seqüência Vulcano-Sedimentar do Rio Itapicuru (Bahia, Brasil) revelando uma parte da história da evolução crustal, proterozóica inferior, do Cráton do São Francisco (1997), pp. 409-412. , SEMANA DE GEOQUÍMICA, 10.CONGRESSO DE GEOQUÍMICA DOS PAISES DE LÍNGUA PORTUGUESA, 4.,1997. Braga. Actas. Braga: Universidade do MinhoSilva, M.G., Coelho, C.E.S., Teixeira, J.B.G., Alves Da Silva, F.C., Silva, R.A., Souza, J.A.B., The Rio Itapicuru greenstone belt, Bahia, Brazil: Geologic evolution and review of gold mineralization (2001) Mineralium Deposita, 36, pp. 345-357Souza, J.D., Abram, M.B., Santos, R.A., Melo, R.C., The basement of the northeastern São Francisco Craton (2000), Field trip Salavador: CPRM/Geological Survey of Brazil 2000Tapponnier, P., Peltzer, G., Armijo, R., On the mechanics of the collision between India and Asia (1986) Collision Tectonics, pp. 115-157. , COWARD, M. P.RIES, A. C. (Eds.) Oxford: Geological Society (Geological Society Special Publication, 19)Teixeira, W., Figueiredo, M.C.H., An outline of Early Proterozoic crustal evolution in the São Francisco Craton, Brazil: A review (1991) Precambrian Research, 53, pp. 1-22Teixeira, W., Sabaté, P., Barbosa, J., Noce, C.M., Carneiro, M.A., Archean and Paleoproterozoic Tectonic Evolution of the São Francisco Craton (2000) Tectonic Evolution of South America, pp. 101-137. , CORDANI, U. G.MILANI, E. J.THOMAZ FILHOCAMPOS, D.A. (Eds) In: Rio de JaneiroTezini, F.C., Oliveira, E.P., O granito eliptico do Riacho do Traga: Marcador de retrabalhamento do Bloco Arqueano de Uauá (Bahia) durante colisão continental paleoproterozóica (2002), p. 344. , CONGRESSO BRASILEIRO GEOLOGIA, 41., 2002. João Pessoa. Anais. João Pessoa: SBGWindley, B.F., (1995) The Evolving Continents, p. 526. , 3 ed. New York: John Wiley & Son

1.76 Ga Volcano-plutonism In The Southwestern Amazonian Craton, Aripuanã-mt, Brazil: Tectono-stratigraphic Implications From Shrimp U-pb Zircon Data And Rock Geochemistry

Paleoproterozoic felsic and mafic volcanic rocks, extrusive and hypabyssal quartz porphyry, and high-K, A-type epizonal granites dominate the Aripuanã region in the southwestern Amazonian craton in the Mato Grosso state of Brazil. The extrusive and intrusive felsic rocks display similar major and trace elements abundance's and equivalent SHRIMP U-Pb ages of 1762-1755 Ma; contacts between them in the field occur gradually. The felsic volcanic activity occurred predominantly as explosive subaqueous volcanism. Various features such as absence of plate collision evidences, lack of any sign of oceanic crust, lack of complete trends of magmatic differentiation, and bimodal characteristics suggest that the magmatism was intracratonic. The characteristically undeformed felsic igneous rocks were formed by extensional events, probably triggered by mantle activation in an intracratonic 'anorogenic' or post-collisional environment. Throughout the Amazonian craton there are wide areas displaying similar magmatism responsible for the generation of distinctive A-type granites. These A-type granites and associated volcanic rocks yield ages of ∼ 1.76 Ga, suggesting that they are genetically linked and that there was a unique tectonic mechanism of widespread action in this craton. © 2002 Elsevier Science B.V. All rights reserved.1191-4171187Almeida, F.F.M., Evolução tectônica do cráton do guaporé comparada com o escudo báltico (1974) Rev. Brasil Geoci., 4, pp. 191-204Compston, W., Williams, I.S., Meyer, C., U-Pb geochronology of zircons from lunar breccia 73217 using a sensitive high mass-resolution ion microprobe (1984) J. Geophys. Res., 89, pp. 525-534Costa, J.B.S., Hasui, Y., Evolução geológica da Amazônia (1997) Sociedade Brasileira de Geologia, pp. 15-90. , Costa, M.L., Angélica, R.S. (Eds.), Contribuiçõs à Geologia da Amazônia (in Portuguese)Dall'Agnol, R., Lafon, J.M., Macambira, M.J.B., Proterozoic anorogenic magmatism in the Central Amazonian Province, Amazonian Craton: Geochronological, petrological and geochemical aspects (1994) Mineral. Petrol., 50, pp. 113-138De Laeter, J.R., Kennedy, A.K., A double focusing mass spectometer for geochronology (1998) Int. J. Mass Spect., 178, pp. 43-50Eby, G.N., The A-type granitoids: A review of their occurrence and chemical characteristics and speculations on their petrogenesis (1990) Lithos, 26, pp. 115-134Geraldes, M.C., Teixeira, W., Van Schmus, W.R., Isotopic and chemical evidence for three accretionary magmatic arcs ( 1.79-1.42 Ga) in the SW Amazon Craton, Mato Grosso State (2000) Brazil. Rev. Brasil. Geoci., 30 (1), pp. 99-101Irvine, T.R., Baragar, W.R.A., A guide to the chemical classification of the common volcanic rocks (1971) Can. J. Earth Sci., 8, pp. 523-548Karlstrom, K.E., Harlan, S.H., Williams, M.L., McLelland, J., Geissman, J.W., Ahäll, K.I., Refining rodinia: Geologic evidence for the Australia - Western US connection in the proterozoic (1999) GSA Today, 9 (10), pp. 4-7Keavey, P., Vine, F.J., (1994) Global Tectonics, , Blackwell, OxfordLe Maitre, R.W., Bateman, P., Dudek, A., Keller, J., Lamiere, J., Le Bas, M.J., Sabine, P.A., Zanettin, B., (1989) A Classification of Igneous Rocks and Glossary of Terms, , Blackwell, OxfordManiar, P.D., Picolli, P.M., Tectonic discrimination granitoids (1989) Geol. Soc. Am. Bull., 101, pp. 635-643Miyashiro, A., Volcanic rock series in volcanic arcs and active continental margins (1974) Am. J. Sci., 274, pp. 321-355Montalvão, R.M.G., Bezerra, P.E.L., Drago, V.A., Cunha, B.C.C., Cobertura de plataforma da amazônia sua sedimentação e evolução tectônica (1984) Anais do XXXIII Congresso Brasileiro de Geologia, pp. 2101-2123. , Rio de Janeiro, in PortugueseNeder, R.D.N., Figueiredo, B.R., Beaudry, C., Collins, C., Leite, J.A.D., The expedito massive sulfide deposit (2000) Mato Grosso. Rev. Brasil. Geoci., 30 (2), pp. 222-225Nuttmann, A., Kinny, P.D., Compston, W., Williams, I.S., Shrimp U-Pb zircon geochronology of the Narrier Gneiss Complex, Western Australia (1991) Precambrian Res., 52, pp. 275-300Pearce, J.A., Trace element characteristics of lavas from destructive plate margins (1982) Andesites, Orogenic Andesites and Related Rocks, pp. 525-548. , Thorpe, R.S. (Ed.), Wiley, ChichesterPearce, J.A., Cann, J.R., Tectonic setting of mafic volcanic rocks determined using trace element analyses (1973) Earth Planet Sci. Lett., 19, pp. 290-300Pearce, J.A., Harris, N.B.W., Tindle, A.G., Trace element discrimination diagrams for the tectonic interpretation of granitic rocks (1984) J. Petrol., 25, pp. 956-983Pinho, M.A.S.B., Lima, E.F., Chemale F., Jr., (1999) Geologia da Região do Moriru-Dados Preliminares da Formação Iriri-Aripuanã-Mato Grosso. Boletim de Resumos, p. 14. , Programa VII Simpósio de Geologia do Centro-Oeste e X Simpósio de geologia de Minas Gerais, Brasília, in PortuguesePinho, M.S.A.B., Pinho, F.E.C., Quadros, A.P., Chemale F., Jr., (2001) Discussao do Termo Uatumã-Iriri, Região Norte do Estado de Mato Grosso-Brasil. Resumos Expandidos - VII Simpósio de Geologia da Amazônia, pp. 15-18. , Sociedade Brasileira de Geologia, Belém, in PortugueseSantos, J.O.S., (2000) Os Terrenos Paleoproterozóicos da Provincia Tapajós e as Mineralizações de Ouro Associadas, , Ph.D. thesis, Univ. Federal do Rio Grande do Sul, Brazil, in PortugueseSchobbenhaus, C., Hoppe, A., Lorke, A., Baumann, A., (1994) Idade U/Pb do Magmatismo Uatumã no Norte do Cráton Amazônico. Escudo das Guianas (Brasil): Primeiros Resultados, 2, pp. 395-397. , Sociedade Brasileira de Geologia, XXXVIII Congresso Brasileira de Geologia Ext. Abstr., in PortugueseSilva, H.A., Leal, J.W.L., Montalvão, R.M.G., Bezerra, P.E.L., Pimenta, O.N.S., Tassinari, C.C.G., Fernandes, C.A.C., Geologia (1980) Projecto RADAM-BRASIL, pp. 21-116. , Folha SC-21 Juruena, DNPM/MME, Rio de Janeiro, in PortugueseSmith, J.B., Barley, M.E., Groves, D.I., Krapez, B., McNaughton, N.J., Bickle, M.J., Chapman, H.J., The Scholl shear zone, West Pilbara: Evidence for a terrane boundary structure from integrated tectonic analyses, SHRIMP U/Pb dating and isotopic and geochemical data of granitoids (1998) Precambrian Res., 88, pp. 143-171Tassinari, C.C.G., (1981) Evolução Tectônica da Província Rio Negro-Juruena na Região Amazônica, , Dissertação de MSc. Univ. São Paulo, Brazil (in Portuguese)Tassinari, C.C.G., (1996) O Mapa Geocronológico do Cráton Amazônico no Brasil: Revisão dos dados Isotópicos, , Tese de livre Docência, Univ. São Paulo, Brazil, (in Portuguese)Tassinari, C.C.G., Macambira, M.J.B., Geochronological provinces of the Amazonian Craton (1999) Episodes, 22 (3), pp. 174-181Tassinari, C.C.G., Cordani, U.G., Nutman, P., Van Schmus, W.R., Bettencourt, J.S., Taylor, P.N., Geochronological systematics on basement rocks from the Rio Negro-Juruena Province (Amazonian Craton) and tectonic implications (1996) Int. Geol. Rev., 38, pp. 161-175Trompette, R., Carozi, A.C., (1994) Geology of Western Gondwana, , A.A. Balkema, RotterdamVavra, G., Systematics of internal zircon morphology in major Variscan granitoid types (1994) Contrib. Mineral. Petrol., 117, pp. 331-344Vasquez, M.L., Klein, E.L., Quadros, M.L.E., Bahia, R.B.C., Santos, A., Ricci, P., Sachett, C.R., Macambira, M.J.B., Magmatismo uatumã na província tapajós - Novos dados geocronológicos. VI Simpósio de Geologia da Amazônia (1999) Ext. Abstr. Bull., pp. 471-474. , in PortugueseVasquez, M.L., Klein, E.L., Ricci, P.S.F., Granitóides pós-colisionais da porção leste da província tapajós. VII Simpósio de Geologia da Amazônia (2001) Ext. Abstr. Bull., pp. 46-54. , in PortugueseWinchester, J.A., Floyd, P.A., Geochemical discrimination of different magma series and their differentiation products using imobile elements (1977) Chem. Geol., 20, pp. 325-34

Deformation history of the Naraku Batholith, Mt Isa Inlier, Australia: implications for pluton ages and geometries from structural study of the Dipvale Grandiorite and Levian Granite

Plutons of the Naraku Batholith were emplaced into Proterozoic metasediments of the northern portion of the Eastern Fold Belt of the Mt Isa Inlier during two intrusive episodes approximately 200 million years apart. Structural relationships and geochronological data suggest that the older plutons (ca 1750 Ma) are contemporaneous with granites of the Wonga Batholith to the west. The Dipvale Granodiorite and the Levian Granite represent these older intrusive phases of the Naraku Batholith, and both contain an intense tectonic foliation, S1, which is interpreted to have formed during the north–south shortening associated with D1 of the Isan Orogeny. The geometry of S1 form surfaces at the southern end of the Dipvale Granodiorite, and of the previously unrecognised sheeted contact, defines a macroscopic, steeply south-southwest-plunging antiform, which was produced by the regional D2 of the Isan Orogeny. S1 form surfaces in the Levian Granite define open F2 folds with wavelengths of several hundred metres. The structural age of emplacement of the Dipvale Granodiorite and the Levian Granite is interpreted to be pre- or syn- the regional D1. An intense foliation present in some of the younger (ca 1505 Ma) granites that comprise the bulk of the Naraku Batholith is interpreted to represent S3 of the Isan Orogeny. Foliations commonly have similar styles and orientations in both the pre-D1 and younger plutons. This emphasises the simplicity with which regional fabrics can be, and probably have been, miscorrelated in the Eastern Fold Belt, and that the classification of granites in general on the basis of structural and geometric criteria alone is fraught with danger