Sulfide inclusion chemistry and carbon isotopes of African diamonds

Details Sulfide inclusion chemistry and carbon isotopes of African diamonds Sulfide inclusion chemistry and carbon isotopes of African diamonds

Aug 1995

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1995gecoa..59.3173h&link_type=abstract

Geochimica et Cosmochimica Acta, vol. 59, Issue 15, pp.3173-3188

Mathematics

Logic

9

Scientific paper

Significant differences in the composition of sulfide mineral inclusions among diamond suites from Koffiefontein, Orapa, Premier, Roberts Victor, Jagersfontein, Sierra Leone, Star, and Mwadui have been found. The mode of the Ni content of the monosulfide (mss) inclusions lies between 8 and 10 wt%, i.e., between the means for mss from Siberian diamonds with inclusion of the eclogitic (3 wt% Ni) and peridotitic (23 wt% Ni) paragenesis. Considering the ratios of the diamond mss inclusions and mantle olivines, together with experimental and naturally observed distribution coefficients, we conclude that less than 20% of the mss inclusions of the African diamonds (mostly from Koffiefontein) could have been in chemical equilibrium with mantle olivine. This observation is in sharp contrast with the reported relative abundance of silicate inclusions in Koffiefontein diamonds (93% peridotitic, 7% eclogitic) and lends support to the proposal that a separate sulfide diamond paragenesis should be recognized. The 13 C distributions of sulfide containing diamonds differs among kimberlites, however, for each kimberlite sulfide and silicate inclusion containing diamonds cover the same 13 C range. Sulfides with high Ni concentrations can occur in diamonds of low as well as high 13 C content. The current observations, in conjunction with other chemical properties of diamonds suggest that fluid reactions rather than silica melt equilibria may be important in diamond formation. A dominance of fluid processes would have significant implications for the interpretation of the chemical and geochronological record of diamond inclusions.

Affiliated with

Also associated with

No associations

Rating

Sulfide inclusion chemistry and carbon isotopes of African diamonds 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 Sulfide inclusion chemistry and carbon isotopes of African diamonds, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Sulfide inclusion chemistry and carbon isotopes of African diamonds will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1270315