TY - JOUR

T1 - Specific multiphase assemblages of carbonatitic and al-rich silicic diamond-forming fluids/melts

T2 - TEM observation of microinclusions in cuboid diamonds from the placers of Northeastern Siberian craton

AU - Logvinova, Alla

AU - Zedgenizov, Dmitry

AU - Wirth, Richard

PY - 2019/1/1

Y1 - 2019/1/1

N2 - The microinclusions in cuboid diamonds from Ebelyakh River deposits (northeastern Siberian craton) have been investigated by FIB/TEM techniques. It was found that these microinclusions have multiphase associations, containing silicates, oxides, carbonates, halides, sulfides, graphite, and fluid phases. The bulk chemical composition of the microinclusions indicates two contrasting growth media: Mg-rich carbonatitic and Al-rich silicic. Each media has their own specific set of daughter phases. Carbonatitic microinclusions are characterized by the presence of dolomite, phlogopite, apatite, Mg, Fe-oxide, KCl, rutile, magnetite, Fe-sulfides, and hydrous fluid phases. Silicic microinclusions are composed mainly of free SiO 2 phase (quartz), high-Si mica (phengite), Al-silicate (paragonite), F-apatite, Ca-carbonates enriched with Sr and Ba, Fe-sulfides, and hydrous fluid phases. These associations resulted from the cooling of diamond-forming carbonatitic and silicic fluids/melts preserved in microinclusions in cuboid diamonds during their ascent to the surface. The observed compositional variations indicate different origins and evolutions of these fluids/melts.

AB - The microinclusions in cuboid diamonds from Ebelyakh River deposits (northeastern Siberian craton) have been investigated by FIB/TEM techniques. It was found that these microinclusions have multiphase associations, containing silicates, oxides, carbonates, halides, sulfides, graphite, and fluid phases. The bulk chemical composition of the microinclusions indicates two contrasting growth media: Mg-rich carbonatitic and Al-rich silicic. Each media has their own specific set of daughter phases. Carbonatitic microinclusions are characterized by the presence of dolomite, phlogopite, apatite, Mg, Fe-oxide, KCl, rutile, magnetite, Fe-sulfides, and hydrous fluid phases. Silicic microinclusions are composed mainly of free SiO 2 phase (quartz), high-Si mica (phengite), Al-silicate (paragonite), F-apatite, Ca-carbonates enriched with Sr and Ba, Fe-sulfides, and hydrous fluid phases. These associations resulted from the cooling of diamond-forming carbonatitic and silicic fluids/melts preserved in microinclusions in cuboid diamonds during their ascent to the surface. The observed compositional variations indicate different origins and evolutions of these fluids/melts.

KW - Cuboid diamonds

KW - Diamond-forming fluids/melts

KW - Mantle

KW - Microinclusions

KW - CRYSTALLIZATION

KW - HIGH-PRESSURE

KW - microinclusions

KW - ION-BEAM FIB

KW - MANTLE FLUIDS

KW - cuboid diamonds

KW - FLUID INCLUSIONS

KW - MINERAL INCLUSIONS

KW - TRACE-ELEMENTS

KW - PHASE

KW - EVOLUTION

KW - mantle

KW - FIBROUS DIAMONDS

KW - diamond-forming fluids/melts

UR - http://www.scopus.com/inward/record.url?scp=85061740132&partnerID=8YFLogxK

U2 - 10.3390/min9010050

DO - 10.3390/min9010050

M3 - Article

AN - SCOPUS:85061740132

VL - 9

JO - Minerals

JF - Minerals

SN - 2075-163X

IS - 1

M1 - 50

ER -