TY - JOUR

T1 - Carbonate-silicate composition of diamond-forming media of fibrous diamonds from the Snap Lake area (Canada)

AU - Zedgenizov, D. A.

AU - Pokhilenko, N. P.

AU - Griffin, W. L.

PY - 2015/3/1

Y1 - 2015/3/1

N2 - This study presents new data on the compositions of microinclusions in fibrous diamonds from the Snap Lake area in the eastern part of the Slave Craton (Canada). The compositional trends of diamond microinclusions are consistent with those of diamond-forming media ranging continuously between a highly carbonatitic endmember and a highly silicic endmember. The microinclusions exhibit general enrichment of most incompatible elements, which is probably indicative of their crystallization during partial melting of mantle peridotites and eclogites. Our results also suggest that the diamond analyzed in this study may have formed as a result of interaction between carbonate-silicate melts and peridotitic wall-rocks at the base of a thick lithospheric mantle at depths below 300 km. The trace element distributions in the studied diamond microinclusions show a general similarity to those previously found in the parental kimberlites and carbonatites. These data suggest that diamonds may have crystallized either directly from a kimberlitic/carbonatitic melt or from a proto-kimberlitic fluid/melt, which was derived from a source also common to kimberlites. This is supported by differences in the major element compositions of diamond-forming fluids/melts and kimberlites.

AB - This study presents new data on the compositions of microinclusions in fibrous diamonds from the Snap Lake area in the eastern part of the Slave Craton (Canada). The compositional trends of diamond microinclusions are consistent with those of diamond-forming media ranging continuously between a highly carbonatitic endmember and a highly silicic endmember. The microinclusions exhibit general enrichment of most incompatible elements, which is probably indicative of their crystallization during partial melting of mantle peridotites and eclogites. Our results also suggest that the diamond analyzed in this study may have formed as a result of interaction between carbonate-silicate melts and peridotitic wall-rocks at the base of a thick lithospheric mantle at depths below 300 km. The trace element distributions in the studied diamond microinclusions show a general similarity to those previously found in the parental kimberlites and carbonatites. These data suggest that diamonds may have crystallized either directly from a kimberlitic/carbonatitic melt or from a proto-kimberlitic fluid/melt, which was derived from a source also common to kimberlites. This is supported by differences in the major element compositions of diamond-forming fluids/melts and kimberlites.

UR - http://www.scopus.com/inward/record.url?scp=84928324707&partnerID=8YFLogxK

U2 - 10.1134/S1028334X15030241

DO - 10.1134/S1028334X15030241

M3 - Article

AN - SCOPUS:84928324707

VL - 461

SP - 297

EP - 300

JO - Doklady Earth Sciences

JF - Doklady Earth Sciences

SN - 1028-334X

IS - 1

ER -