Magmatic processes beneath the volcanic island of Saba

Magmatic processes beneath the volcanic island of Saba

Zomerdijk, M.

Molengraaff Fonds

2015

The volcanic island of Saba is located in the Caribbean Sea and is part of the Lesser Antilles volcanic arc. The andesitic domes of Saba preserve a lot of andesitic host rocks as well as basaltic enclaves. In this project the geochemical signatures of Li, Be and Cl are studied to identify the source of the basalts and andesitic rocks. ⁸⁷Sr/⁸⁶Sr isotope ratios in combination with Be/Nb values suggest one source for both the basalts as the andesitic rocks. Zr/Nb and ⁸⁷Sr/⁸⁶Sr isotope data suggest that the contribution of sediment to the mantle source was limited. Zr/Nb and Li/Yb ratios are suggesting a depleted mantle source. Enrichments in the fluid mobile elements Li and Cl provide evidence for fluid flux melting and a subduction component. Fractional crystallization, reactivation of solidified mafic melts and magma mixing seem to determine the geochemical signature in the felsic rocks. The geochemical composition of Saba is comparable with other Lesser Antilles volcanics besides an increasing sediment signature from north to south.

http://resolver.tudelft.nl/uuid:f9499853-91f5-4dfd-b83d-535e233fc3ef

Vrije Universiteit Amsterdam

Geoscience Reports

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