The 2014-15 eruption and the short-term geochemical evolution of the Fogo volcano (Cape Verde)::Evidence for small-scale mantle heterogeneity
| Autor: | Nadine Mattielli, Rita Caldeira, B F Faria, João Mata, Ricardo S. Ramalho, L. Martins, José Madeira, Sofia Martins, João J.P.G.L.M. Rodrigues, Marcelo M.J. Moreira, Pedro Silva |
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| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: |
Ocean island basalts
geography Radiogenic nuclide geography.geographical_feature_category 010504 meteorology & atmospheric sciences Partial melting Geochemistry Short-term magmatic variation Geology 2014-15 Fogo Island (Cape Verde) eruption Magma chamber Volcano plumbing system 010502 geochemistry & geophysics 01 natural sciences Mantle (geology) Cape verde Volcano 13. Climate action Geochemistry and Petrology Phenocryst 2014–15 Fogo Island (Cape Verde) eruption Kaersutite Mantle heterogeneity 0105 earth and related environmental sciences |
| Zdroj: | Mata, J, Martins, S, Mattielli, N, Madeira, J, Faria, B, Ramalho, R S, Silva, P, Moreira, M, Caldeira, R, Rodrigues, J & Martins, L 2017, ' The 2014-15 eruption and the short-term geochemical evolution of the Fogo volcano (Cape Verde): Evidence for small-scale mantle heterogeneity ', Lithos, vol. 288-289, pp. 91-107 . https://doi.org/10.1016/j.lithos.2017.07.001 Repositório Científico de Acesso Aberto de Portugal Repositório Científico de Acesso Aberto de Portugal (RCAAP) instacron:RCAAP |
| DOI: | 10.1016/j.lithos.2017.07.001 |
| Popis: | Recurrent eruptions at very active ocean island volcanoes provide the ideal means to gain insight on the scale of spatial variations at the mantle source and on temporal changes of magma genesis and evolution processes. In 2014, after 19 years of quiescence, Fogo volcano (Cape Verde Archipelago) experienced a new eruption, with the vents located 200 m from those of the 1995 eruption, and less than 2000 m from those of the 1951 event. This offered a unique opportunity to investigate the existence of small-scale mantle heterogeneities and the short-term compositional evolution of magmas erupted by a very active oceanic volcano like Fogo. Here we present petrological and geochemical data from the early stages of the Fogo's most recent eruption - started on November 23, 2014 - and compare them with the signature of previous eruptions (particularly those of 1995 and 1951). The magmas erupted in 2014 are alkaline (up to 23.4% and 0.94% of normative ne and lc, respectively) with somewhat evolved compositions (Mg # < 56), ranging from tephrites to phonotephrites. The eruption of phonotephritic lavas preceded the effusion of tephritic ones. Lavas carried to the surface clinopyroxene and kaersutite phenocrysts and cognate megacrysts, which indicate that the main stages of magma evolution occurred in magma chambers most probably located at mantle depths (25.6 5.5 km below sea level). This was followed by a shallower ( |
| Databáze: | OpenAIRE |
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