|
|
Beaumais, Aurelien; Bertrand, Herve; Chazot, Gilles; Dosso, Laure; Robin, Claude. |
Gaua Island (also called Santa Maria), from the central part of the Vanuatu arc, consists of a large volcano marked by a caldera that hosts the active Mount Garet summit cone. In this paper, a geochemical study including Sr, Nd, Pb and Hf isotopic compositions of 25 lavas emitted since 1.8 Ma is presented, with a focus on the volcanic products that preceded (old volcanics, main cone and pyroclastic series) and followed (Mount Garet) the caldera forming event. All lavas show an island arc signature with enrichment in LILE and depletion in HFSE. Post-caldera lavas define a medium-K calc-alkaline trend, whereas lavas from the former main cone have high-K calc-alkaline compositions. Compared to the pre-caldera volcanic suite, the Mount Garet lavas have... |
Tipo: Text |
Palavras-chave: Gaua; Vanuatu; Geochemistry; Isotopes; Subduction; Mantle source. |
Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00319/43052/42557.pdf |
| |