Инд. авторы:	Shatskiy A., Borzdov Y.M., Litasov K.D., Sharygin I.S., Palyanov Y.N., Ohtani E.
Заглавие:	Phase relationships in the system K2CO3-CaCO3 at 6 GPa and 900-1450 degrees C
Библ. ссылка:	Shatskiy A., Borzdov Y.M., Litasov K.D., Sharygin I.S., Palyanov Y.N., Ohtani E. Phase relationships in the system K2CO3-CaCO3 at 6 GPa and 900-1450 degrees C // American Mineralogist. - 2015. - Vol.100. - Iss. 1. - P.223-232. - ISSN 0003-004X. - EISSN 1945-3027.
Внешние системы:	DOI: 10.2138/am-2015-5001; SCOPUS: 2-s2.0-84921346700; WoS: 000347436600025;
Реферат:	eng: Phase relations in the system K2CO3-CaCO3 have been studied in the compositional range, X(K2CO3), from 100 to 10 mol%, at 6.0 GPa and 900-1450 degrees C. At 900-950 degrees C, the system has three intermediate compounds: K6Ca2(CO3)(5), K2Ca(CO3)(2), and K2Ca3(CO3)(4). The K2Ca(CO3)(2) compound decomposes to the K6Ca2(CO3)(5)+ K2Ca3(CO3)(4) assembly above 950 degrees C. The K6Ca2(CO3)(5) and K2Ca3(CO3)(4) compounds melt congruently slightly above 1200 and 1300 degrees C, respectively. The eutectics were established at 64 and 44 mol% near 1200 degrees C and at 23 mol% near 1300 degrees C. K2CO3 remains as a liquidus phase at 1300 degrees C and 75 mol% and melts at 1425 +/- 20 degrees C. Aragonite remains as a liquidus phase at 1300 degrees C and 20 mol% and at 1400 degrees C and 10 mol%. CaCO3 solubility in K2CO3 and K2CO3 solubility in aragonite are below the detection limit (<0.5 mol%). Infiltration of subduction-derived K-rich Ca-Mg-Fe-carbonatite into the Fe-0-saturated mantle causes the extraction of (Mg,Fe)CO3 components from the melt, which shifts its composition toward K-Ca-carbonatite. According to our data this melt can be stable at the P-T conditions of subcratonic lithosphere with geothermal gradient of 40 mW/m(2) corresponding to temperature of 1200 degrees C at 6 GPa.
Ключевые слова:	UP KAWAI-CELL; HIGH-PRESSURE; EARTHS MANTLE; HIGH-TEMPERATURE; METAMORPHIC DEVOLATILIZATION; DIAMOND CRYSTALLIZATION; THERMAL-DECOMPOSITION; DEEP CARBON-CYCLE; buetschliite; fairchildite; high-pressure experiment; carbonatite; Earth's mantle; NORTHEASTERN SIBERIAN PLATFORM; SINGLE-CRYSTAL GROWTH; Alkaline carbonates;
Издано:	2015
Физ. характеристика:	с.223-232