@article{PAR00000156,
  title = {{B}asalt petrology, zircon ages and sapphire genesis from {D}ak {N}ong, southern {V}ietnam},
  author = {{G}arnier, {V}. and {O}hnenstetter, {D}. and {G}iuliani, {G}. and {F}allick, {A}. {E}. and {T}rong, {T}. {P}. and {Q}uang, {V}. {H}. and {V}an, {L}. {P}. and {S}chwarz, {D}.},
  editor = {},
  language = {{ENG}},
  abstract = {{B}asalts associated with sapphire deposits are widespread in {E}urope, {A}frica, {A}sia and {A}ustralia. {I}n {V}ietnam, blue, green and yellow sapphires are recovered from eluvial and alluvial placers hosted in basaltic fields of the {D}ak {L}ak {P}rovince. {T}wo distinct basalt suites are recognized in this field: a tholeiitic suite without any xenocrysts and an alkaline suite with mantle and lower crustal xenocrysts. {T}he sapphires are enriched in {F}e (0.43 to 1.26 wt.%), with moderate contents of {C}r (33-1582 ppm), {T}i (35-1080 ppm), {G}a (149-308 ppm) and {V} (28-438 ppm) and they are poor in {Z}n and {M}g. {T}heir {O}-isotope compositions range from 6.0 to 6.9 parts per thousand and are not in equilibrium with the alkali basalts which have delta(18){O} values between 5.0 and 5.7 parts per thousand. {T}he {U}-{P}b dating of zircons recovered from the basaltic placers provides evidence of two eruptional events: one at similar to 6.5 {M}a followed by another one at similar to 1 {M}a. {T}he petrography of the basalts and the oxygen isotopic composition of the sapphires suggest that the sapphires are xenocrysts and that they crystallized in a deep magma chamber, at the lower continental lithosphere and the upper mantle boundary, in evolved melts issued from the fractionation of alkali basaltic magmas contaminated with lower crustal fluids.},
  keywords = {sapphire ; basalt ; petrography ; geochemistry ; zircon ; {U} {P}b dating by {SIMS} ; oxygen isotopes ; {V}ietnam},
  booktitle = {},
  journal = {{M}ineralogical {M}agazine},
  volume = {69},
  numero = {1},
  pages = {21--38},
  ISSN = {0026-461{X}},
  year = {2005},
  DOI = {10.1180/0026461056910233},
  URL = {https://www.documentation.ird.fr/hor/{PAR}00000156},
}