@article{fdi:010068904,
  title = {{P}etro-geochemical constraints on the source and evolution of magmas at {E}l {M}isti volcano ({P}eru)},
  author = {{R}ivera, {M}. and {M}artin, {H}. and {L}e {P}ennec, {J}ean-{L}uc and {T}houret, {J}. {C}. and {G}ourgaud, {A}. and {G}erbe, {M}. {C}.},
  editor = {},
  language = {{ENG}},
  abstract = {{E}l {M}isti volcano, a large and hazardous edifice of the {A}ndean {C}entral {V}olcanic {Z}one ({CVZ}) of southern {P}eru, consists of four main growth stages. {M}isti 1 (>112 ka) is an old stratovolcano partly concealed by two younger stratocones ({M}isti 2, 112-40 ka; {M}isti 3, 38-11 ka), capped in turn by a recent summit cone ({M}isti 4, <11 ka). {I}n order to gain insights into magma composition controls on eruptive behaviour through time at {E}l {M}isti, we have conducted a petrological and geochemical study of selected rock samples from the main growth stages of the volcano. {W}hole rock compositions range from andesite to rhyolite and belong to a medium to high-{K} calk alkaline magmatic suite. {E}l {M}isti samples are characterised by high large-ion lithophile elements, but low concentrations of high field strength elements, and heavy rare earth elements, consistent with a subduction zone setting. {T}he {S}r-87/{S}r-86 (0.70715-0.70882) and {N}d-143/{N}d-144 (0.511983-0.512277) isotope ratios suggest that magma composition is significantly affected by contamination and/or assimilation processes during their evolution, likely due to the presence of thick (65-70 km) continental crust beneath the {CVZ} in southern {P}eru. {G}eochemical evidence indicates that magmatic evolution is mostly controlled by {A}ssimilation-{F}ractional {C}rystallisation ({AFC}) mechanisms. {M}odelling reveals a mass-assimilated/mass-fractionated ratio (p) <= 2.2, which suggests an assimilated crust fraction below 14 wt.% on average. {O}ur isotopic data clearly identify the {P}roterozoic "{C}harcani gneiss" basement as the main contaminant. {B}oth contamination and assimilation processes peaked at similar to 30 wt.%, during the {M}isti 3 stage when rhyolites were generated. {W}e ascribe the general depletion in {HREE} and {Y} and elevated {L}a/{Y}b and {S}r/{Y} ratios in {E}l {M}isti samples to the enrichment of the mantle wedge source of the parental magmas by a felsic melt of adakitic composition and hydrous fluids. {O}ur work highlights that {E}l {M}isti's magmatic system has remained relatively homogeneous since at least 0.12 {M}a, with a marked influence of the contaminating crust in the {L}ate {P}leistocene {M}isti 3 stage, which resulted in highly explosive eruptions. {A}ndesitic-dacitic compositions are dominant in the {H}olocene and historical {M}isti 4 stage, and are expected for future volcanic events at {E}l {M}isti.},
  keywords = {{E}l {M}isti ; {C}entral {A}ndes ; {A}rc magmatism ; {M}agmatic evolution ; {G}eochemistry ; {A}ssimilation-fractional crystallisation ; {PEROU} ; {ANDES} ; {EL} {MISTI} {VOLCAN}},
  booktitle = {},
  journal = {{L}ithos},
  volume = {268},
  numero = {},
  pages = {240--259},
  ISSN = {0024-4937},
  year = {2017},
  DOI = {10.1016/j.lithos.2016.11.009},
  URL = {https://www.documentation.ird.fr/hor/fdi:010068904},
}