New experimental data on phase relations for the system Na2CO3-CaCO3 at 6 GPa and 900-1400  C

Phase relationships in the system K2CO3-CaCO3 at 6 GPa and 900-1450 C

“…The binary carbonate with similar stoichiometry, Na 2 Ca 3 (CO 3 ) 4 , was also established in the Na 2 CO 3 -CaCO 3 system at 900-1300 °C and 6 GPa (Shatskiy et al 2013d;Gavryushkin et al 2014).…”

“…Since carbonates could participate in various mantle processes (kimberlite magma generation, mantle metasomatism, and diamond formation) that have occurred at the base of subcratonic mantle (150-230 km depths), pressure of about 6 GPa is the most interesting for the study of those systems. Although phase relations in the CaCO 3 -MgCO 3 (Buob et al 2006), CaCO 3 -FeCO 3 ), K 2 CO 3 -MgCO 3 (Shatskiy et al 2013c), Na 2 CO 3 -MgCO 3 (Shatskiy et al 2013a), and Na 2 CO 3 -CaCO 3 (Shatskiy et al 2013d) systems were already studied at 6 GPa, the data on phase relations in the K 2 CO 3 -CaCO 3 system are limited by pressures ≤0.1 GPa (Niggli 1916;Eitel and Skaliks 1929;Kröger et al 1943;Ragone et al 1966;Chattaraj et al 1973;Cooper et al 1975;Malik et al 1985;McKie 1990;Gavryushkin et al 2014;Jago and Gittins 1991;Arceo and Glasser 1995) (Fig. 1).…”

Melting phase relations of the Udachnaya-East Group-I kimberlite at 3.0–6.5 GPa: Experimental evidence for alkali-carbonatite composition of primary kimberlite melts and implications for mantle plumes

“…Table 6). Run T1781 (6.5 GPa, 900 o C) contains a Na-bearing carbonate with molar (Na+K)/Ca ≈ 0.44 -0.45; taking into account correction factors from Shatskiy et al, (2013c) it probably has the stoichiometry of the (Na,K) 2 Ca 4 (CO 3 ) 5 phase (Litasov et al, 2013b). Raman spectra of our Na-bearing carbonate are similar to Raman spectra of Na 2 Ca 4 (CO 3 ) 5 phase ( Fig.…”

The K₂CO₃ fusion curve revisited: New experiments at pressures up to 12 GPa

“…Moreover, alkali carbonates can be used as a medium for the formation of diamonds in the Earth's mantle (Pal'yanov et al, 1999(Pal'yanov et al, , 2002Sokol et al, 2000). It is thus essential to understand the behavior of alkali carbonate liquids at mantle conditions, which has been discussed only in recent studies (Dobson et al, 1996;Liu and Lange, 2003;Liu et al, 2007;Litasov et al, 2013;Shatskiy et al, 2013aShatskiy et al, , 2013b. In the research of Litasov et al (2013), the true solidi of Na-and K-bearing carbonate systems at high pressure were determined, and the possibility of subducting alkaline carbonates melting at the transition zone was reported.…”

“…In the research of Litasov et al (2013), the true solidi of Na-and K-bearing carbonate systems at high pressure were determined, and the possibility of subducting alkaline carbonates melting at the transition zone was reported. Phase relations in simple binary carbonates systems such as K 2 CO 3 -MgCO 3 and Na 2 CO 3 -CaCO 3 have been studied by Shatskiy et al (2013aShatskiy et al ( , 2013b.…”