TY - JOUR

T1 - The mineralogy of Ca-rich inclusions in sublithospheric diamonds

AU - Zedgenizov, D. A.

AU - Ragozin, A. L.

AU - Kalinina, V. V.

AU - Kagi, H.

PY - 2016/10/1

Y1 - 2016/10/1

N2 - This paper discusses mineralogy of Ca-rich inclusions in ultra-deep (sublithospheric) diamonds. It was shown that most of the Ca-rich majoritic garnets are of metabasic (eclogitic) affinity. The observed variation in major and trace element composition is consistent with variations in the composition of the protolith and the degree of enrichment or depletion during interaction with melts. Major and trace element compositions of the inclusions of Ca minerals in ultra-deep diamonds indicate that they crystallized from Ca-carbonatite melts that were derived from partial melting of eclogite bodies in deeply subducted oceanic crust in the transition zone or even the lower mantle. The occurrence of merwinite or CAS inclusions in ultra-deep diamonds can serve as mineralogical indicators of the interaction of metaperidotitic and metabasic mantle lithologies with alkaline carbonatite melts. The discovery of the inclusions of carbonates in association with ultra-deep Ca minerals can not only provide additional support for their role in the diamond formation process but also help to define additional mantle reservoirs involved in global carbon cycle.

AB - This paper discusses mineralogy of Ca-rich inclusions in ultra-deep (sublithospheric) diamonds. It was shown that most of the Ca-rich majoritic garnets are of metabasic (eclogitic) affinity. The observed variation in major and trace element composition is consistent with variations in the composition of the protolith and the degree of enrichment or depletion during interaction with melts. Major and trace element compositions of the inclusions of Ca minerals in ultra-deep diamonds indicate that they crystallized from Ca-carbonatite melts that were derived from partial melting of eclogite bodies in deeply subducted oceanic crust in the transition zone or even the lower mantle. The occurrence of merwinite or CAS inclusions in ultra-deep diamonds can serve as mineralogical indicators of the interaction of metaperidotitic and metabasic mantle lithologies with alkaline carbonatite melts. The discovery of the inclusions of carbonates in association with ultra-deep Ca minerals can not only provide additional support for their role in the diamond formation process but also help to define additional mantle reservoirs involved in global carbon cycle.

KW - diamond

KW - inclusions

KW - lower mantle

KW - Са minerals

UR - http://www.scopus.com/inward/record.url?scp=84990961105&partnerID=8YFLogxK

U2 - 10.1134/S0016702916100116

DO - 10.1134/S0016702916100116

M3 - Article

AN - SCOPUS:84990961105

VL - 54

SP - 890

EP - 900

JO - Geochemistry International

JF - Geochemistry International

SN - 0016-7029

IS - 10

ER -