Contribution
Mantle sources and differentiation of alkaline magmatic suite of Lages, Santa Catarina, Brazil
Traversa, Glanbosco; Barbieri, Mario; Beccaluva, Luigl; Coltorti, Massimo; Conte, Aida Maria; Garbarino, Carlo; Gomes, Celso B.; Macciotta, Glampaolo; Morbidelli, Lucio; Ronca, Sara; Scheibe, Luiz F.
European Journal of Mineralogy Volume 8 Number 1 (1996), p. 193 - 208
47 références bibliographiques
publié: Feb 22, 1996
manuscrit accepté: Oct 24, 1995
manuscrit reçu: Feb 6, 1995
DOI: 10.1127/ejm/8/1/0193
Abstract
Abstract The alkaline-carbonatite district of Lages (Santa Catarina, Brazil) contains mafic-ultramafic and prevalent leucocratic bodies mainly composed of olivine melilitites, olivine nephelinites, basanites, phonotephrites, nepheline syenites and peralkaline phonolites. Kimberlitic pipe breccias and carbonatitic rocks are also present. Petrography, mineral and bulk-rock chemistry and mass balance calculations show that differentiated leucocratic rock-types can be derived by fractional crystallization processes from basanitic magmas. Trace element and Sr-Nd isotopic data suggest metasomatized mantle sources for the primary magmas and variable crustal contamination for the more differentiated rock-types.
Mots-clefs
igneous petrology • Sr-Nd isotopes • basanite-peralkaline phonolite • Brazil