Journal articles
Exploring the links between volcano flank collapse and the magmatic evolution of an ocean island volcano: Fogo, Cape Verde
Abstract : Abstract Mass-wasting of ocean island volcanoes is a well-documented phenomenon. Massive flank collapses may imply tens to hundreds of km 3 and generate mega-tsunamis. However, the causal links between this large-scale, low-frequency instability, and the time–space evolution of magma storage, crystal fractionation/accumulation, lithospheric assimilation, and partial melting remains unclear. This paper aims at tracking time variations and links between lithospheric, crustal and surface processes before and after a major flank collapse (Monte Amarelo collapse ca. 70 ka) of Fogo volcano, Cape Verde Islands, by analysing the chemical composition (major, trace elements, and Sr–Nd–Pb isotopes) and age-controlled stratigraphy (K–Ar and Ar–Ar dating) of lavas along vertical sections (Bordeira caldera walls). The high-resolution sampling allows detecting original variations of composition at different time-scales: (1) a 60 kyrs-long period of increase of magma differentiation before the collapse; (2) a 10 kyrs-long episode of reorganization of magma storage and evacuation of residual magmas (enriched in incompatible elements) after the collapse; and (3) a delayed impact at the lithospheric scale ~ 50 kyrs after the collapse (increasing EM1-like materiel assimilation).
https://hal.uca.fr/hal-03335357
Contributor : Sylvaine Jouhannel <>
Submitted on : Monday, September 6, 2021 - 10:47:31 AM
Last modification on : Wednesday, September 15, 2021 - 3:30:10 AM
Contributor : Sylvaine Jouhannel <>
Submitted on : Monday, September 6, 2021 - 10:47:31 AM
Last modification on : Wednesday, September 15, 2021 - 3:30:10 AM
File
Cornu_Sci-Rep_2021.pdf
Files produced by the author(s)
Licence
Distributed under a Creative Commons Attribution 4.0 International License
