Инд. авторы:	Bataleva Y.V., Kruk A.N., Novoselov I.D., Palyanov Y.N.
Заглавие:	Formation of Spessartine and CO(2)via Rhodochrosite Decarbonation along a Hot Subduction P-T Path
Библ. ссылка:	Bataleva Y.V., Kruk A.N., Novoselov I.D., Palyanov Y.N. Formation of Spessartine and CO(2)via Rhodochrosite Decarbonation along a Hot Subduction P-T Path // MINERALS. - 2020. - Vol.10. - Iss. 8. - Art.703.
Внешние системы:	DOI: 10.3390/min10080703; WoS: 000564702300001;
Реферат:	eng: Experimental simulation of rhodochrosite-involving decarbonation reactions resulting in the formation of spessartine and CO2-fluid was performed in a wide range of pressures (P) and temperatures (T) corresponding to a hot subductionP-Tpath. Experiments were carried out using a multi-anvil high-pressure apparatus of a "split-sphere" type (BARS) in an MnCO3-SiO2-Al(2)O(3)system (3.0-7.5 GPa, 850-1250 degrees C and 40-100 h.) with a specially designed high-pressure hematite buffered cell. It was experimentally demonstrated that decarbonation in the MnCO3-SiO2-Al(2)O(3)system occurred at 870 +/- 20 degrees C (3.0 GPa), 1070 +/- 20 degrees C (6.3 GPa), and 1170 +/- 20 degrees C (7.5 GPa). Main Raman spectroscopic modes of the synthesized spessartine were 349-350 (R), 552(upsilon(2)), and 906-907 (upsilon(1)) cm(-1). As evidenced by mass spectrometry (IRMS) analysis, the fluid composition corresponded to pure CO2. It has been experimentally shown that rhodochrosite consumption to form spessartine + CO(2)can occur at conditions close to those of a hot subductionP-Tpath but are 300-350 degrees C lower than pyrope + CO(2)formation parameters at constant pressures. We suppose that the presence of rhodocrosite in the subducting slab, even as solid solution with Mg,Ca-carbonates, would result in a decrease of the decarbonation temperatures. Rhodochrosite decarbonation is an important reaction to explain the relationship between Mn-rich garnets and diamonds with subduction/crustal isotopic signature.
Ключевые слова:	FINSCH; STABILITY; TRANSITION; CO2; DIAMOND; KIMBERLITE PIPE; MINERAL INCLUSIONS; HIGH-PRESSURE; CARBONATION; mantle; subduction; decarbonation; manganese; rhodochrosite; CO(2)fluid; spessartine; high-pressure experiment; MNCO3;
Издано:	2020
Физ. характеристика:	703