Other
Scientific paper
Feb 2007
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2007gecoa..71..723k&link_type=abstract
Geochimica et Cosmochimica Acta, Volume 71, Issue 3, p. 723-744.
Other
23
Scientific paper
The analysis of micro-inclusions in fibrous diamonds from the Diavik mine, Canada revealed the presence of high density fluids (HDFs) that span a continuous compositional range between carbonatitic and saline end-members. The carbonatitic end-member is rich in Na, Ca, Mg, Fe, Ba and carbonate; the saline one is rich in K, Cl and water. In molar proportions, the composition of the saline end-member is: K38Na7.7Ca1.8Mg1.6Fe1.5Ba1.9SiO3.1Cl46(CO3)5.5(H2O)56 and that of the carbonatitic end member is: K15Na21Ca6.7Mg8.1Fe6.2Ba5.7Si4.8Ti1.4Al1.9O17Cl29(CO3)29(H2O)29. The micro-inclusions in one diamond span a narrow range between a silicic end-member (rich in Si, K and water) and a carbonatitic one (rich in Mg, Ca, Fe and carbonate). Its average composition is: K26Na5.5Ca13.8Mg8.3Fe9.6Ba0.9P2.5Si25Ti1.6Al3.8Cl2.5O81(CO3)29(H2O)78. Thus, the Diavik diamonds span most of the known compositional range for fluids trapped in diamonds. Based on these data and previous analyses of fluids trapped in diamonds, we discuss possible models for the evolution of diamond-forming fluids. The most plausible model is where carbonatitic-HDFs are parental to all the other compositions. They evolve by fractionation of divalentions- and alkali-carbonates and by immiscible separation into saline- and silicic-HDFs. Each phase continues to evolve separately, crystallizing carbonates, diamond, and accessory silicates, phosphates, halides and more of the immiscible phase. Other processes, like the mixing of evolved fluids with fresh parental carbonatitic fluids, or metasomatic interactions with the wallrock also play a role in the evolution of the HDFs. We also propose that the parental carbonatitic-HDF evolves through fractional crystallization of an alkali-rich, low degree melt that is similar to the high pressure parental melts of kimberlites or lamproites.
Hauri Erik
Izraeli Elad S.
Klein-BenDavid Ofra
Navon Oded
No associations
LandOfFree
Fluid inclusions in diamonds from the Diavik mine, Canada and the evolution of diamond-forming fluids does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Fluid inclusions in diamonds from the Diavik mine, Canada and the evolution of diamond-forming fluids, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Fluid inclusions in diamonds from the Diavik mine, Canada and the evolution of diamond-forming fluids will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-738270