Fallick A. E. auteur aut IRD Giuliani Gaston auteur aut IRD Rigaudier T. auteur aut IRD Boyce A. J. auteur aut IRD Pham V. L. auteur aut IRD Pardieu V. auteur aut IRD text journalArticle eng text/pdf born digital access Oxygen isotope systematics for co-existing pairs of gem-spinel and calcite in marble from Vietnam and other worldwide deposits have been determined in order to characterize the O-isotope fractionation between calcite and spinel. In Vietnam, the Delta O-18(cc-sp) (= 3.7 + 0.1 parts per thousand for six samples from the An Phu and Cong Troi deposits) is remarkably constant. The combination of these data with those obtained on calcite-spinel pairs of Paigutan (Nepal, n = 2), Ipanko (Tanzania, n = 1), and Mogok (Myanmar, = 2) are also consistent with an overall Delta O-18(cc-sp) of 3.6 + 0.3 parts per thousand for all the spinel samples (n = 11). The straight line correlation delta O-18(cc) = 0.96 delta O-18(sp) + 4.4 is excellent despite their worldwide geographic spread. The increment method of calculating oxygen isotope fractionation gave a geologically unreasonable temperature of formation for both minerals at 1374 degrees C when compared to temperatures obtained by mineral assemblage equilibrium of these marble type deposits, between 610 and 750 degrees C. The constant Delta O-18(cc-sp) reflects a constant temperature for this amphibolite facies assemblage, whose current best estimate is calculated at 620 + 40 degrees C, but unquantified uncertainties remain. specialized Marble deposits Asia East Africa Spinel-calcite pair Oxygen isotope fractionation Temperature of formation VIET NAM TANZANIE NEPAL MYANMAR TADJIKISTAN PAKISTAN KENYA 064 351 1 27-36 2019 1631-0713 https://www.documentation.ird.fr/hor/fdi:010075174 10.1016/j.crte.2018.11.008 1631-0713 [F B010075174] https://www.documentation.ird.fr/hor/fdi:010075174 https://www.documentation.ird.fr/intranet/publi/2019/02/010075174.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2019-03-06 2025-02-24 fdi:010075174 fre