TY - JOUR
T1 - Fibrous diamonds from the placers of the northeastern Siberian Platform
T2 - Carbonate and silicate crystallization media
AU - Zedgenizov, D. A.
AU - Ragozin, A. L.
AU - Shatsky, V. S.
AU - Araujo, D.
AU - Griffin, W. L.
PY - 2011/11
Y1 - 2011/11
N2 - The first data are presented on the compositions of microinclusions in fibrous diamonds from the Ebelyakh placers, northeastern Siberian Platform. Their fluid/melt microinclusions are of silicate or carbonate compositions. In general, the trace element patterns for the microinclusions correspond to kimberlites and carbonatites. The major-element composition differs significantly; for example, the microinclusions are considerably enriched in K and Na. In two of the studied diamonds, the microinclusion compositions differ considerably in the cores and rims. In one of them, the composition of the medium changes from chloride-carbonate to predominantly carbonate (sample HI-90); in the other one, from carbonate to silicate (sample HI-98). Similar carbon isotope characteristics of diamonds with microinclusions of two contrasting media might suggest their crystallization from a mantle reservoir with the same carbon isotope characteristics. The geochemical features of the microinclusions in the placer diamonds revealed their relationship with protokimberlitic carbonate-silicate fluids. Such fluids might result from the metasomatic interaction of volatiles and/or the low-degree partial melting of peridotite and eclogite substrates.
AB - The first data are presented on the compositions of microinclusions in fibrous diamonds from the Ebelyakh placers, northeastern Siberian Platform. Their fluid/melt microinclusions are of silicate or carbonate compositions. In general, the trace element patterns for the microinclusions correspond to kimberlites and carbonatites. The major-element composition differs significantly; for example, the microinclusions are considerably enriched in K and Na. In two of the studied diamonds, the microinclusion compositions differ considerably in the cores and rims. In one of them, the composition of the medium changes from chloride-carbonate to predominantly carbonate (sample HI-90); in the other one, from carbonate to silicate (sample HI-98). Similar carbon isotope characteristics of diamonds with microinclusions of two contrasting media might suggest their crystallization from a mantle reservoir with the same carbon isotope characteristics. The geochemical features of the microinclusions in the placer diamonds revealed their relationship with protokimberlitic carbonate-silicate fluids. Such fluids might result from the metasomatic interaction of volatiles and/or the low-degree partial melting of peridotite and eclogite substrates.
UR - http://www.scopus.com/inward/record.url?scp=80455156312&partnerID=8YFLogxK
U2 - 10.1016/j.rgg.2011.10.003
DO - 10.1016/j.rgg.2011.10.003
M3 - Article
AN - SCOPUS:80455156312
SN - 1068-7971
VL - 52
SP - 1298
EP - 1309
JO - Russian Geology and Geophysics
JF - Russian Geology and Geophysics
IS - 11
ER -