scholarly journals Experimental Modeling of Ankerite–Pyrite Interaction under Lithospheric Mantle P–T Parameters: Implications for Graphite Formation as a Result of Ankerite Sulfidation

Minerals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1267
Author(s):  
Yuliya V. Bataleva ◽  
Ivan D. Novoselov ◽  
Yuri M. Borzdov ◽  
Olga V. Furman ◽  
Yuri N. Palyanov
Keyword(s):  
High Pressure ◽  
Redox Reactions ◽  
Elemental Carbon ◽  
Iron Concentration ◽  
Experimental Modeling ◽  
Diamond Growth ◽  
Carbon Formation ◽  
Sulfide Melt ◽  
Redox Interaction ◽  
High Pressure Apparatus

Experimental modeling of ankerite–pyrite interaction was carried out on a multi-anvil high-pressure apparatus of a “split sphere” type (6.3 GPa, 1050–1550 °C, 20–60 h). At T ≤ 1250 °C, the formation of pyrrhotite, dolomite, magnesite, and metastable graphite was established. At higher temperatures, the generation of two immiscible melts (carbonate and sulfide ones), as well as graphite crystallization and diamond growth on seeds, occurred. It was established that the decrease in iron concentration in ankerite occurs by extraction of iron by sulfide and leads to the formation of pyrrhotite or sulfide melt, with corresponding ankerite breakdown into dolomite and magnesite. Further redox interaction of Ca,Mg,Fe carbonates with pyrrhotite (or between carbonate and sulfide melts) results in the carbonate reduction to C0 and metastable graphite formation (±diamond growth on seeds). It was established that the ankerite–pyrite interaction, which can occur in a downgoing slab, involves ankerite sulfidation that triggers further graphite-forming redox reactions and can be one of the scenarios of the elemental carbon formation under subduction settings.

scholarly journals Sulfide Formation as a Result of Sulfate Subduction into Silicate Mantle (Experimental Modeling under High P,T-Parameters)

Minerals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 373 ◽  
Author(s):  
Yuliya Bataleva ◽  
Yuri Palyanov ◽  
Yuri Borzdov
Keyword(s):  
Experimental Study ◽  
High Pressure ◽  
Lithospheric Mantle ◽  
Experimental Modeling ◽  
Silicate Melt ◽  
Free System ◽  
Oxide Melt ◽  
High Pressure Apparatus

Ca,Mg-sulfates are subduction-related sources of oxidized S-rich fluid under lithospheric mantle P,T-parameters. Experimental study, aimed at the modeling of scenarios of S-rich fluid generation as a result of desulfation and subsequent sulfide formation, was performed using a multi-anvil high-pressure apparatus. Experiments were carried out in the Fe,Ni-olivine–anhydrite–C and Fe,Ni-olivine–Mg-sulfate–C systems (P = 6.3 GPa, T of 1050 and 1450 °C, t = 23–60 h). At 1050 °C, the interaction in the olivine–anhydrite–C system leads to the formation of olivine + diopside + pyrrhotite assemblage and at 1450 °C leads to the generation of immiscible silicate-oxide and sulfide melts. Desulfation of this system results in the formation of S-rich reduced fluid via the reaction olivine + anhydrite + C → diopside + S0 + CO2. This fluid is found to be a medium for the recrystallization of olivine, extraction of Fe and Ni, and subsequent crystallization of Fe,Ni-sulfides (i.e., olivine sulfidation). At 1450 °C in the Ca-free system, the generation of carbonate-silicate and Fe,Ni-sulfide melts occurs. Formation of the carbonate component of the melt occurs via the reaction Mg-sulfate + C → magnesite + S0. It is experimentally shown that the olivine-sulfate interaction can result in mantle sulfide formation and generation of potential mantle metasomatic agents—S- and CO2-dominated fluids, silicate-oxide melt, or carbonate-silicate melt.

scholarly journals Graphite and Diamond Formation in the Carbide–Oxide–Carbonate Interactions (Experimental Modeling under Mantle P,T-Conditions)

Minerals ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 522 ◽  
Author(s):  
Yuliya Bataleva ◽  
Yuri Palyanov ◽  
Yuri Borzdov ◽  
Ivan Novoselov ◽  
Oleg Bayukov
Keyword(s):  
Redox Reactions ◽  
Experimental Modeling ◽  
Silicate Melt ◽  
Diamond Growth ◽  
Potential Mechanism ◽  
Diamond Formation ◽  
Reducing Conditions ◽  
Reduction Of Co2 ◽  
Fluid Interactions

Experimental modeling of the formation of graphite and diamond as a result of carbide–fluid interactions was performed in the Fe3C–SiO2–Al2O3–(Mg,Ca)CO3 systems at 6.3 and 7.5 GPa and 1100–1650 °C. In the experiments with ƒO2-gradient (7.5 GPa, 1250–1350 °C), graphite + magnesiowüstite + garnet ± cohenite assemblage was formed. Graphite was produced through the redox interactions of carbide with carbonate or CO2 (reducing conditions), and redox reactions of magnesiowüstite and CO2 (oxidizing conditions). At 1450–1650 °C, crystallization of graphite, garnet, magnesiowüstite and ferrospinel, as well as generation of Fe2+,3+-rich carbonate–silicate melt occurred. This melt, saturated with carbon, acted as a medium of graphite crystallization and diamond growth on seeds. In the experiments without ƒO2-gradient (6.3 GPa), decarbonation reactions with the formation of CO2-fluid and Fe,Mg,Ca-silicates, as well as C0-producing redox reactions of CO2-fluid with cohenite were simultaneously realized. As a result, graphite (± diamond growth) was formed in assemblage with Fe2+,Fe3+,Mg-silicates and magnetite (1100–1200 °C), or with Fe3+-rich garnet and orthopyroxene (1300–1500 °C). It has been established that a potential mechanism for the crystallization of graphite or diamond growth is the oxidation of cohenite by CO2-fluid to FeO and Fe3O4, accompanied by the extraction of carbon from Fe3C and the corresponding reduction of CO2 to C0.

An effective method for elimination of the defects in diamond caused by physical field asymmetry in high-pressure synthesis cavities

CrystEngComm ◽  
2020 ◽  
Vol 22 (47) ◽  
pp. 8266-8273
Author(s):  
Chunxiao Wang ◽  
Hong-an Ma ◽  
Liangchao Chen ◽  
Shuai Fang ◽  
Jian Wang ◽  
...  
Keyword(s):  
High Pressure ◽  
Physical Field ◽  
Diamond Growth ◽  
High Pressure Synthesis ◽  
Growth Defects ◽  
Pressure Synthesis

FEM was used to explain the mechanism of diamond growth defects and methods were proposed to eliminate the growth defects.

High-temperature calibration of a multi-anvil high pressure apparatus

2015 ◽  
Vol 35 (2) ◽  
pp. 139-147 ◽  
Author(s):  
Alexander G. Sokol ◽  
Yury M. Borzdov ◽  
Yury N. Palyanov ◽  
Alexander F. Khokhryakov
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Temperature Calibration ◽  
High Pressure Apparatus

scholarly journals High-pressure apparatus for use with a cryogenic magnetometer.

1981 ◽  
Vol 33 (8) ◽  
pp. 449-466 ◽  
Author(s):  
S. J. PIKE ◽  
T. L. HENYEY ◽  
J. REVOL ◽  
M. D. FULLER
Keyword(s):  
High Pressure ◽  
High Pressure Apparatus

Fundamentals of strength and durability calculations for high-pressure apparatus elements

Physica B+C ◽  
1986 ◽  
Vol 139-140 ◽  
pp. 782-784 ◽  
Author(s):  
N.V. Novikov ◽  
V.I. Levitas ◽  
S.I. Shestakov
Keyword(s):  
High Pressure ◽  
Strength And Durability ◽  
High Pressure Apparatus

Acoustic detection of cracks in the anvil of a large-volume cubic high-pressure apparatus

2015 ◽  
Vol 86 (12) ◽  
pp. 124904 ◽  
Author(s):  
Zhaoli Yan ◽  
Bin Chen ◽  
Hao Tian ◽  
Xiaobin Cheng ◽  
Jun Yang
Keyword(s):  
High Pressure ◽  
Large Volume ◽  
Acoustic Detection ◽  
High Pressure Apparatus
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