Parental magma characterization of Salitre cumulate rochks (Alto Paranaíba, alkaline province, Brazil) as inferred from mineralogical, petrographic, and geochemical data
| Autor: | Gianbosco Traversa, P. Brotzu, L. Morbidelli, B. F. Riffel, Excelso Ruberti, Luigi Beccaluva, Celso B. Gomes, C. Garbarino |
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| Rok vydání: | 1997 |
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| Zdroj: | Repositório Institucional da USP (Biblioteca Digital da Produção Intelectual) Universidade de São Paulo (USP) instacron:USP Scopus-Elsevier |
| Popis: | The Alto Paranaiba alkaline province (∼82 Ma), tectonically associated with a NW-trending linear structure bordering the Sao Francisco craton, consists of a wide variety of igneous forms and magma types. It includes several alkaline-carbonatite complexes, some of which are quite important economically. The Salitre complex is represented by two interconnected oval-shaped bodies, N-S-aligned and variable in size, emplaced into Proterozoic metasedimentary rocks. It consists mainly of syenites showing clear evidence of fenitization, ultramafic rocks (clinopyroxenites, mica-bearing clinopyroxenites, locally referred to as bebedourites, dunites, glimmerites, and per-ovskitites), radial dikes of trachytes/tinguaites, and carbonatites as small veins and also forming an elongated plug, approximately 500 m2 in area, associated with the Salitre I intrusion. In a few cases the carbonatitic rocks grade into phoscorites because of an increase in magnetite content. Texturally, the ultramafites are described as adcumulat... |
| Databáze: | OpenAIRE |
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