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Peritectic Reaction of Olivine as Mechanism of Ultrabasic-Basic Evolution of the Diamond-Forming System Silicate-Carbonate-(C-O-H): Experiments at 6.0 GPa
Litvin, Y.A.; Kuzyura, A.V.; Spivak, A.V. The Peritectic Reaction of Olivine as the Mechanism of the Ultrabasic–Basic Evolution of the Diamond-Forming Silicate-Carbonate-(C-O-H) System: Experiments at 6.0 GPa. Minerals2023, 13, 1040.
Litvin, Y.A.; Kuzyura, A.V.; Spivak, A.V. The Peritectic Reaction of Olivine as the Mechanism of the Ultrabasic–Basic Evolution of the Diamond-Forming Silicate-Carbonate-(C-O-H) System: Experiments at 6.0 GPa. Minerals 2023, 13, 1040.
Litvin, Y.A.; Kuzyura, A.V.; Spivak, A.V. The Peritectic Reaction of Olivine as the Mechanism of the Ultrabasic–Basic Evolution of the Diamond-Forming Silicate-Carbonate-(C-O-H) System: Experiments at 6.0 GPa. Minerals2023, 13, 1040.
Litvin, Y.A.; Kuzyura, A.V.; Spivak, A.V. The Peritectic Reaction of Olivine as the Mechanism of the Ultrabasic–Basic Evolution of the Diamond-Forming Silicate-Carbonate-(C-O-H) System: Experiments at 6.0 GPa. Minerals 2023, 13, 1040.
Abstract
Melting phase relations of the diamond-forming system olivine (Ol) – jadeite (Jd) – diopside (Di) – (Mg, Fe, Ca, Na)-carbonates (Carb*) – (C-O-H-fluid) are studied in experiments at 6.0 GPa in the polythermal section Ol74Carb*18.5(C-O-H)7.5 - Omp74Carb*18.5(C-O-H)7.5, where Ol = Fo80Fa20, Omp (omphacite) = Jd62Di38 and Carb* = (MgCO3)25(FeCO3)25(CaCO3)25(Na2CO3)25. Peritectic reaction of olivine and jadeite-bearing melt with formation of garnet has been determined as a physico-chemical mechanism of ultrabasiс-basiс evolution of the diamond-forming system. In the process CO2-component of the supercritical C-O-H-fluid can react with silicate components to form additional carbonates of Mg, Fe, Ca and Na. Solidus temperature of the diamond-forming system is depressed to 1000-1020°C by joint effect of the H2O-fluid and carbonate constituents thereof. The experimentally recognized peritectic mechanism of ultrabasiс-basiс evolution of the diamond-forming system explains the origin of the associated paragenetic inclusions of peridotite and eclogite minerals in diamonds as well as the xenoliths of diamond-bearing peridotites and eclogites of the kimberlitic deposits of diamond. The diamond-forming systems have formed with the use of material of the upper mantle native peridotite rocks. In this case the capacity of the rocks to run the peritectic reaction of olivine was transmitted with silicate components to the diamond-forming systems.
Keywords
diamond-forming silicate-carbonate system; С-О-Н-fluid; peritectic reaction of olivine; ultrabasic-basic evolution; origin of diamond-bearing peridotites and eclogites; high pressure and temperature; experiment
Subject
Environmental and Earth Sciences, Geochemistry and Petrology
Copyright:
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