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1 Introduction The Paraná Basin is a part of the Paraná-Angola-Namibia (Etendeka) Province (PAEP [ 1 ]). It is characterized by Early Cretaceous flood basalts (tholeiites) and dyke swarms (130–135 Ma, according to refs. [ 2 , 3 , 4 , 5 ] and references therein) associated with alkaline and alkaline–carbonatite complexes of Early Cretaceous to Tertiary age [ 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 ]. The emplacement of these complexes, in and around the PAEP, occurred mainly along tectonic structures active at least since the Early Mesozoic ( Figure 1 ), and up to

[1] Hornig I., Rare Earth Elements in Sovitic Carbonatites and their Mineral Phases. J. Petrol., 1998, 39, 2105–2121 http://dx.doi.org/10.1093/petroj/39.11-12.2105 [2] Bhushan S.K., Kumar A., First Carbonatite Hosted REE Deposit from India. J. Geol. Soc. India, 2013, 81, 41–60 http://dx.doi.org/10.1007/s12594-013-0005-y [3] Kumar D., Mamallan R., Dwivedy K. K., Carbonatite magmatism in northeast India. J. Southeast Asian Earth Sci., 1996, 13, 145–158 http://dx.doi.org/10.1016/0743-9547(96)00016-5 [4] Srivastava R.K., Sinha A.K., The early Cretaceous Sung Valley

1 Introduction Carbonatite melts are known to form by very low degrees of partial melting of the carbonated olivine-rich (peridotitic) mantle forming interconnected melts at fractions lower than 0.05 wt%. The grain size is considered to be of the order of 1 mm with low diahedral wetting angles (~28°) and low viscosities [ 1 , 2 ]. Such mantle is envisaged as a veined and metasomatically enriched source region [ 3 ]. The carbonatitic magma so generated represent ionic solutions and hence are unpolymerised melts with lower viscosity (~ 5 × 10 −3 poise), high

American Mineralogist, Volume 88, pages 1822–1824, 2003 0003-004X/03/1112–1822$05.00 1822 INTRODUCTION Carbonatites are rare rocks on the Earth’s surface, but they are believed to be important agents of mantle metasomatism. Moreover, some economically important deposits of the rare- earth elements and niobium are hosted by carbonatites (Bell 1989). Although there is no doubt that the ultimate source of carbonatites is in the mantle, a variety of processes may be involved in their formation and differentiation. Carbonatite mag- mas may be generated by partial

American Mineralogist, Volume 98, pages 1074–1077, 2013 0003-004X/13/0506–1074$05.00/DOI: http://dx.doi.org/10.2138/am.2013.4410 1074 Letter High-pressure aragonite phenocrysts in carbonatite and carbonated syenite xenoliths within an alkali basalt VratisLaV Hurai,1,* Monika HuraioVá,2 rastisLaV MiLoVský,3 JarMiLa LuptákoVá,3 and Patrik konečný4 1Geological Institute, Slovak Academy of Sciences, Dúbravská cesta 9, 840 05 Bratislava, Slovakia 2Department of Mineralogy and Petrology, Comenius University, Mlynská dolina, 842 15 Bratislava, Slovakia 3

Pauloabibite, trigonal NaNbO3, isostructural with ilmenite, from the Jacupiranga carbonatite, Cajati, São Paulo, Brazil Luiz A.D. Menezes FiLho1,†, DAnieL Atencio2,*, MArceLo B. AnDrADe3, roBert t. Downs4, Mário L.s.c. chAves1, Antônio w. roMAno1, ricArDo schoLz5 AnD ABA i.c. PersiAno6 1Instituto de Geociências, Universidade Federal de Minas Gerais, Avenida Antônio Carlos, 6627, 31270-901, Belo Horizonte, Minas Gerais, Brazil 2Instituto de Geociências, Universidade de São Paulo, Rua do Lago 562, 05508-080, São Paulo, São Paulo, Brazil 3Instituto de Física de

References ARZAMASTSEV A.A., ARZAMASTSEVA L.V., BELYATSKY B.V., 1998: Initial alkaline volcanism of the Palaeozoic tectonic and magmatic activation in the North-Eastern Fennoscandia: geochemical features and petrological consequences. Petrology 6, 316-336 (in Russian). BAILEY D.K., 1993: Carbonatite magmas. Journal of Geological Society (London) 150, 637-651. BELL K., BLENKINSOP J., 1987: Archean depleted mantle: Evidence from Nd and Sr initial isotopic ratios of carbonatites. Geochimica and Cosmochimica Acta 51, 291-298. BELL K., 1998: Radiogenic isotope

[1] Streckeisen A., Classification and nomenclature of volcanic rocks, lamprophyres, carbonatites and melilitic rocks. IUGS Subcomission on the Systematics of Igneous Rocks. Geol Rundsch, 1980, 69, 194–207 [2] Dobson D.P., Jones A.P., Rabe R., Sekine T., Kurita K., Taniguchi T., Kondo T., Kato T., Shimomura O., Urakawa S., In-situ measurement of viscosity and density of carbonate melts at high pressure. Earth. Planet. Sci. Lett., 1996, 143(1–4), 207–215 http://dx.doi.org/10.1016/0012-821X(96)00139-2 [3] Wolff J.A., Physical properties of carbonatite magmas

American Mineralogist, Volume 93, pages 1230–1244, 2008 0003-004X/08/0809–1230$05.00/DOI: 10.2138/am.2008.2712 1230 Monazite ages from carbonatites and high-grade assemblages along the Kambam Fault (Southern Granulite Terrane, South India) ElizabEth J. Catlos,1,* Chandra s. dubEy,2 and Poovalingam sivasubramanian3 1 School of Geology, Oklahoma State University, 105 Noble Research Center, Stillwater, Oklahoma 74078, U.S.A. 2 Department of Geology, University of Delhi, Delhi, 110007, India 3Marine Geochemistry Research Lab, SPIC Research Center, VO

[1] Bayanova T.B., Baddeleyite: A Promising Geochronometer for Alkaline and Basic Magmatism. Petrology, 2006, 14, 187–200 http://dx.doi.org/10.1134/S0869591106020032 [2] Zozulya D.R., Bayanova T.B., Eby G.N., Geology and Age of the Late Archean Keivy Alkaline Province, northeastern Baltic Shield. J. Geol., 2005, 113, 601–608 http://dx.doi.org/10.1086/431912 [3] Puustinen K., Geology of the Siilinjärvi carbonatite complex, Eastern Finland. Bull. Comm. Géol. Finlande, 1971, 249, 1–43 [4] Zozulya D.R., Bayanova T.B., Serov P.N., Age and Isotopic Geochemical