@article{fdi:010080531,
  title = {{N}oble gas magmatic signature of the {A}ndean {N}orthern {V}olcanic {Z}one from fluid inclusions in minerals},
  author = {{L}ages, {J}. and {R}izzo, {A}. {L}. and {A}iuppa, {A}. and {S}amaniego, {P}ablo and {L}e {P}ennec, {J}ean-{L}uc and {C}eballos, {J}. {A}. and {N}arvaez, {P}. {A}. and {M}oussallam, {Y}ves and {B}ani, {P}hilipson and {S}chipper, {C}. {I}. and {H}idalgo, {S}. and {G}aglio, {V}. and {A}lberti, {E}. and {S}andoval-{V}elasquez, {A}.},
  editor = {},
  language = {{ENG}},
  abstract = {{T}race volatile elements like {H}e are key for understanding the mantle source signature of magmas and to better constrain the relative roles of subduction and crustal processes to the variability of along-arc chemical and isotopic signatures of magmatic fluids. {H}ere we report on noble gas abundances and isotopic data of {F}luid {I}nclusions ({FI}s) in eruptive products and/or fumarolic gases from the {C}olombia-{E}cuador segment of {A}ndean {N}orthern {V}olcanic {Z}one ({NVZ}). {FI}s in olivine phenocrysts from {E}cuador ({E}l {R}eventador, {C}otopaxi and {T}ungurahua) yield air-normalized corrected {H}e-3/{H}e-4 ratios of 7.0-7.4 {R}-{A}, within the {MORB} range (8 +/- 1 {R}-{A}). {W}ith exception of the {C}otopaxi lavas (opx < < oliv.), these are indistinguishable of those obtained for their cogenetic orthopyroxene pairs and of gas emissions previously reported in literature. {O}livine phenocrysts from {N}evado del {R}uiz fissure lavas also yield the highest {H}e-3/{H}e-4 (8.5 +/- 0.3 {R}-{A}) for this volcanic system, which is in the range of fumarolic gases for {G}aleras (previously reported as high as 8.8 {R}-{A} and here measured to a maximum of 8.3 +/- 0.1 {R}-{A}). {O}ur dataset highlights disparities between isotope signatures of eruptive products from {E}cuador (avg. similar to 7.2 {R}-{A}) and those reported for the {C}olombian portion of the {NVZ} (avg. similar to 8.5 {R}-{A}). {P}revious studies on the geochemistry of erupted products put in evidence significant along-arc variations ascribed either to the involvement of different slab components, or to variable depths of evolution of arc magmas within the continental crust. {H}owever, the same variation is not discernible in the signature of noble gases, especially helium, from {FI}s and gas emissions analyzed in this study, with little inter-variation between {C}otopaxi, {R}eventador and {T}ungurahua (all within 0.2 {R}-{A} from the {E}cuador average of 7.2) and {G}aleras and {N}evado del {R}uiz, whose maximum values differ by similar to 0.3 {RA}. {W}e therefore suggest a homogenous {MORB}-like {H}e-3/{H}e-4 signature for the mantle wedge beneath this arc segment, whereby along-arc variations in crustal thickness (from <35 km at the northernmost part of the segment to >= 50 km at the {E}cuadorian arc segment) may factor largely into the variability recorded on our data set. {T}he first {CO}2/{H}e-3 ratios obtained in {FI}s from {A}ndean rocks support the hypothesis of increasing crustal contamination from {C}olombia to {E}cuador, concomitant with increasing crustal thicknesses under the respective arc regions.},
  keywords = {{A}ndean {V}olcanic {B}elt ; {N}orthern {V}olcanic {Z}one ; {F}luid inclusions ; {N}oble gases ; {H}elium ; {C}rustal thickness ; {COLOMBIE} ; {EQUATEUR} ; {ANDES} ; {TUNGURAHUA} {VOLCAN} ; {EL} {REVENTADOR} {VOLCAN} ; {COTOPAXI} {VOLCAN} ; {GALERAS} {VOLCAN} ; {NEVADO} {DEL} {RUIZ} {VOLCAN}},
  booktitle = {},
  journal = {{C}hemical {G}eology},
  volume = {559},
  numero = {},
  pages = {119966 [16]},
  ISSN = {0009-2541},
  year = {2021},
  DOI = {10.1016/j.chemgeo.2020.119966},
  URL = {https://www.documentation.ird.fr/hor/fdi:010080531},
}