Petrological and geochemical evolution of the alkaline Valle Chico Massif, southeastern Uruguay

Nenhuma Miniatura disponível

Data

2002-04-01

Título da Revista

ISSN da Revista

Título de Volume

Editor

V H Winston & Son Inc

Resumo

The Valle Chico Massif is a member of the Early Cretaceous alkaline magmatic suite of rocks distributed around the Parana Basin. Three magmatic associations are recognized: (1) the Plutonic Association, characterized by syenites, quartz syenites, and syenogranites; (2) the Volcanic Association, mainly composed of porphyritic quartz trachytes; and (3) the Porphyritic Dike Association consisting of rhyolites and trachytes. Judging by their geochemical behavior, the rhyolites exhibit a weak peralkaline affinity, and are genetically connected by progressive melting processes, whereas the other lithologies have a metaluminous nature, and are products of mineral fractionation. An enriched mantle of Transamazonian age, geochemically similar to OIB, is postulated as a possible source.

Descrição

Palavras-chave

Como citar

International Geology Review. Palm Beach: V H Winston & Son Inc., v. 44, n. 4, p. 352-369, 2002.