Diamond inclusions

O. Ermer, L Lindenberg, Lorenz, "Double-diamond inclusion compounds of 2,6-dimethylideneadaman-tane-l,35,7-tetracarboxylic acid , Helv. Chim. Acta 1991, 74, 825-8277. 

Sobolev, N.V. Shatsky, V.S. 1990. Diamond inclusions in garnets from metamorphic rocks. Nature, 343, 742-746. 

In contrast, peridotites metasomatized by small melt fractions show enrichment in platinum and palladium and elevated (Pd/Ir) . Bulk mineral separate PGE-Re analyses of two fertile xenoliths from southeastern Australia indicate less than 6% of the whole-rock PGE budget resides in either silicate or oxide phases and further implicates sulfides and alloys as the main controls of PGE-Re abundance. Comparison of sulfide versus whole-rock budgets by Lorand and Alard (2001) demonstrates the dominance of sulfide as the main PGE host in relatively fertile peridotites. This confirms the results of earlier studies of xenolith PGE mass balance (Hart and Ravizza, 1996 Mitchell and Keays, 1981) plus xenolith-derived and diamond inclusion sulfide studies (Jagoutz et al, 1979 Pearson et al, 1998b). As with cratonic xenoliths, sulfur-PGE and major-element-PGE correlations in more depleted noncratonic peridotites indicate that I-PGEs are probably not hosted entirely by sulfide (Lee, 2002). 

Figure 52 Initial ENd ssr isotope plot of calculated whole-rock eclogites from Africa (Koidu—Hills and Haggerty, 1989 Orapa—Smith et al., 1989 Viljoen et al, 1996 Roberts Victor—Jagoutz et al, 1984 Smith et al., 1989 Jacob and Jagoutz, 1994 Bellsbank—Neal et al., 1990), Yakutia (Snyder et al, 1993 Jacob et al, 1994 Pearson et al., 1995a Snyder et al, 1997), and eclogitic inclusions in diamonds (Richardson, 1986 Richardson et al, 1990 1999 Smith et al, 1991). Eclogite data are initial calculated whole-rock neodymium isotope compositions. Strontium isotope compositions are from clinopyroxene only. Cratonic peridotite minerals and diamond inclusions are plotted for comparison. Arrow points to a sample from Udachnaya that has a calculated initial SNd of 484. dashed lines are...

Ireland T. R., Rudnick R. L., and Spetsius Z. (1994) Trace elements in diamond inclusions from eclogites reveal hnk to Archean granites. Earth Planet. Sci. Lett. 128, 199—213. 

Pearson D. G., Shirey S. B., Harris J. W., and Carlson R. W. (1998b) A Re-Os isotope study of sulfide diamond inclusions from the Koffiefontein kimberlite S. Africa constraints on diamond crystallisation ages and mantle Re—Os systematics. Earth Planet. Sci. Lett. 160, 311 -326. 

Sobolev N. V., Yefimova E. S., Channer D. M. D., Anderson P. F. N., and Barron K. M. (1998) Unusual upper mantle beneath Guaniamo, Guyana Shield, Venezuela evidence from diamond inclusions. Geology 26, 971-974. 

BoydF. R., Gurney J. J., and Richardson S. H. (1985) Evidence for a 150—200 km thick Archean hthosphere from diamond inclusion thermobarometry. Nature 315, 387-389. 

Macrocryst sulphide Tj ages sia Uiig a Diamond inclusion sulphide... 

Fig. 3. Trd ages of Siberian whole-rock peridotites (Pearson et al. 1995ft), mostly from the Udachnaya kimberlite, compared with Tma ages of sulphides from Udachnaya olivine macrocrysts (Pearson et al. 2000) and Tma ages from Udachnaya diamond inclusions (Pearson et al. 1999).

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