TY - JOUR

T1 - Silicate melt inclusions in diamonds of eclogite paragenesis from placers on the Northeastern Siberian Craton

AU - Shatsky, Vladislav

AU - Zedgenizov, Dmitry

AU - Ragozin, Alexey

AU - Kalinina, Viktoriya

N1 - Publisher Copyright: © 2019 by the authors.

PY - 2019/7/1

Y1 - 2019/7/1

N2 - New findings of silicate-melt inclusions in two alluvial diamonds (from the Kholomolokh placer, northeastern Siberian Platform) are reported. Both diamonds exhibit a high degree of N aggregation state (60-70% B) suggesting their long residence in the mantle. Raman spectral analysis revealed that the composite inclusions consist of clinopyroxene and silicate glass. Hopper crystals of clinopyroxene were observed using scanning electron microscopy and energy-dispersive spectroscopic analyses; these are different in composition from the omphacite inclusions that co-exist in the same diamonds. The glasses in these inclusions contain relatively high SiO2, Al2O3, Na2O and, K2O. These composite inclusions are primary melt that partially crystallised at the cooling stage. Hopper crystals of clinopyroxene imply rapid cooling rates, likely related to the uplift of crystals in the kimberlite melt. The reconstructed composition of such primary melts suggests that they were formed as the product of metasomatised mantle. One of the most likely source of melts/fluids metasomatising the mantle could be a subducted slab.

AB - New findings of silicate-melt inclusions in two alluvial diamonds (from the Kholomolokh placer, northeastern Siberian Platform) are reported. Both diamonds exhibit a high degree of N aggregation state (60-70% B) suggesting their long residence in the mantle. Raman spectral analysis revealed that the composite inclusions consist of clinopyroxene and silicate glass. Hopper crystals of clinopyroxene were observed using scanning electron microscopy and energy-dispersive spectroscopic analyses; these are different in composition from the omphacite inclusions that co-exist in the same diamonds. The glasses in these inclusions contain relatively high SiO2, Al2O3, Na2O and, K2O. These composite inclusions are primary melt that partially crystallised at the cooling stage. Hopper crystals of clinopyroxene imply rapid cooling rates, likely related to the uplift of crystals in the kimberlite melt. The reconstructed composition of such primary melts suggests that they were formed as the product of metasomatised mantle. One of the most likely source of melts/fluids metasomatising the mantle could be a subducted slab.

KW - Diamond

KW - Diamond-forming fluids/melts

KW - Mantle

KW - Melt inclusions

KW - Mineral inclusions

KW - BEARING ECLOGITE

KW - YAKUTIA

KW - melt inclusions

KW - PIPE

KW - UDACHNAYA KIMBERLITE

KW - FLUID INCLUSIONS

KW - diamond-forming fluids

KW - MANTLE

KW - mineral inclusions

KW - MINERAL INCLUSIONS

KW - diamond

KW - EVOLUTION

KW - GROWTH

KW - mantle

KW - FIBROUS DIAMONDS

KW - melts

UR - http://www.scopus.com/inward/record.url?scp=85070677043&partnerID=8YFLogxK

U2 - 10.3390/min9070412

DO - 10.3390/min9070412

M3 - Article

AN - SCOPUS:85070677043

VL - 9

JO - Minerals

JF - Minerals

SN - 2075-163X

IS - 7

M1 - 412

ER -