@article{fdi:010070896,
  title = {{F}luid inclusion and stable isotope constraints on the formation of the ianapera emerald deposit, southern madagascar},
  author = {{S}alvi, {S}. and {G}iuliani, {G}aston and {A}ndrianjakavah, {P}. {R}. and {M}oine, {B}. and {B}eziat, {D}. and {F}allick, {A}.},
  editor = {},
  language = {{ENG}},
  abstract = {{T}he {I}anapera emerald deposit is hosted in the {N}eoproterozoic {V}ohibory domain of southern {M}adagascar, within a tightly folded metamorphic sequence of mafic and ultramafic rocks ({M}-{UMR}), gneiss, and marble, a few kilometers north of the major tectonic break known as the {I}anapera-{A}mpanihy {S}uture. {L}ate-collisional metaluminous to peraluminous felsic intrusions outcrop in the area. {E}merald occurs mostly within metasomatic phlogopitite and quartz-tourmaline veins, developed within lenses of {M}-{UMR}. {R}ecent work recognized granitic pegmatites as the source of the emerald-forming fluids, leading to the classification of proximal and distal mineralization styles, based on whether or not pegmatites are associated with the phlogopitite, respectively ({A}ndrianjakavah et al. 2009). {C}onsiderations of the chemistry of tourmaline and scapolite associated with emerald and beryl, data from fluid and solid inclusions in these minerals, thermodynamic calculations, and mineral thermobarometric data confirm that {B}e originated from the pegmatites, transported in a moderately saline aqueous fluid that exsolved at about 600 to 680 degrees {C} and 4-6 kbars. {T}his fluid was enriched in alkali elements, incompatible elements and dissolved sulfur, and produced the proximal mineralization. {M}igration along fractures caused loss of at least part of the pegmatitic elements and local mixing with a metamorphic {CO}2-rich fluid, leading to the more distal mineralization at somewhat lower temperatures (520 to 650 degrees {C}). {O}xygen and hydrogen stable isotopes were measured from beryl and emerald; the data corroborate a magmatic-hydrothermal origin for the mineralization and a common source for proximal and distal fluids. {T}he calculated delta {O}-18({H}2{O}) of 12.5% at 520 degrees {C} for the distal emerald and the delta {D}-{H}2{O} range measured from the channel of the emerald samples fit within the oxygen and hydrogen isotopic range of values defined for peraluminous granitic magmatism. {T}he occurrence of a distal style of emerald mineralization such as typified by {I}anapera suggests that metamorphic origin models for similar occurrences worldwide should be taken with care and possibly reconsidered in terms of source and origin of fluids and metals.},
  keywords = {southern {M}adagascar ; {I}anapera ; emerald ; distal and proximal deposits ; fluid inclusions ; {O}-{H} isotopes ; scapolite ; tourmaline ; {P}-{T}-{X} conditions ; metasomatism ; {MADAGASCAR}},
  booktitle = {},
  journal = {{C}anadian {M}ineralogist},
  volume = {55},
  numero = {4},
  pages = {619--650},
  ISSN = {0008-4476},
  year = {2017},
  DOI = {10.3749/canmin.1700017},
  URL = {https://www.documentation.ird.fr/hor/fdi:010070896},
}