An extrusive-plutonic event at hardy point and its vicinitygreenwich Island – Antarctic

• Main Authors: Almeida, Delia Del Pilar M. de, Machado, Adriane, Hansen, Marcos A. F., Fensterseifer, Henrique, Lima, Larissa de, Gomes, Cristiane H.
• Format: Article in Journal/Newspaper
• Language: Portuguese
• Published: Zeppelini Editorial 2000
• Subjects: Antarctic; Hardy Point; Antarc*
• Online Access: http://revistas.ufpr.br/rbg/article/view/10560; https://doi.org/10.5380/rbg.v30i1.10560

The volcanic and intrusive rocks at Hardy Point and its vicinity were formed mainly du1ring a Mesozoic magmatism. Andesiticbasalt flows and andesites constitute the volcanic rocks. The intrusive ones were expressed as an epizonal body, with dioritic to granitic composition, and are cogenetic to the volcanic ones. The geochemical patterns indicate that volcanism preceded plutonism. In rare earth elements diagram the intrusive rocks present a further developed pattern, in which all rocks show calc-alkaline affinity, an enrichment in light rare earth elements relative to the heavy ones, probably due to partial melting of the mantle. In thespidergram (LILE, HFSE) the same pattern is observed for all rock groups, with strong negative anomalies of Ti, P and Nb, typical of island arcs, besides a positive anomaly of Ce, which could berelated to the assimilation of Ce-enriched marine sediments.