scholarly journals Decarbonation Reactions Involving Ankerite and Dolomite under upper Mantle P,T-Parameters: Experimental Modeling

Minerals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 715 ◽  
Author(s):  
Yuliya V. Bataleva ◽  
Aleksei N. Kruk ◽  
Ivan D. Novoselov ◽  
Olga V. Furman ◽  
Yuri N. Palyanov
Keyword(s):  
High Pressure ◽  
Upper Mantle ◽  
Fluid Composition ◽  
High Pressure Cell ◽  
Raman Spectroscopic ◽  
Earth’S Mantle ◽  
Wide Range ◽  
High Pressure Apparatus ◽  
Fluid Release ◽  
Bearing System

An experimental study aimed at the modeling of dolomite- and ankerite-involving decarbonation reactions, resulting in the CO2 fluid release and crystallization of Ca, Mg, Fe garnets, was carried out at a wide range of pressures and temperatures of the upper mantle. Experiments were performed using a multi-anvil high-pressure apparatus of a “split-sphere” type, in CaMg(CO3)2-Al2O3-SiO2 and Ca(Mg,Fe)(CO3)2-Al2O3-SiO2 systems (pressures of 3.0, 6.3 and 7.5 GPa, temperature range of 950–1550 °C, hematite buffered high-pressure cell). It was experimentally shown that decarbonation in the dolomite-bearing system occurred at 1100 ± 20 °C (3.0 GPa), 1320 ± 20 °C (6.3 GPa), and 1450 ± 20 °C (7.5 GPa). As demonstrated by mass spectrometry, the fluid composition was pure CO2. Composition of synthesized garnet was Prp83Grs17, with main Raman spectroscopic modes at 368–369, 559–562, and 912–920 cm−1. Decarbonation reactions in the ankerite-bearing system were realized at 1000 ± 20 °C (3.0 GPa), 1250 ± 20 °C (6.3 GPa), and 1400 ± 20 °C (7.5 GPa). As a result, the garnet of Grs25Alm40Prp35 composition with main Raman peaks at 349–350, 552, and 906–907 cm−1 was crystallized. It has been experimentally shown that, in the Earth’s mantle, dolomite and ankerite enter decarbonation reactions to form Ca, Mg, Fe garnet + CO2 assemblage at temperatures ~175–500 °C lower than CaCO3 does at constant pressures.

scholarly journals Formation of Spessartine and CO2 via Rhodochrosite Decarbonation along a Hot Subduction P-T Path

Minerals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 703
Author(s):  
Yuliya V. Bataleva ◽  
Aleksei N. Kruk ◽  
Ivan D. Novoselov ◽  
Yuri N. Palyanov
Keyword(s):  
High Pressure ◽  
Isotopic Signature ◽  
Experimental Simulation ◽  
Fluid Composition ◽  
Raman Spectroscopic ◽  
Wide Range ◽  
T Path ◽  
The Relationship ◽  
Subducting Slab ◽  
High Pressure Apparatus

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 subduction P-T path. Experiments were carried out using a multi-anvil high-pressure apparatus of a “split-sphere” type (BARS) in an MnCO3–SiO2–Al2O3 system (3.0–7.5 GPa, 850–1250 °C and 40–100 h.) with a specially designed high-pressure hematite buffered cell. It was experimentally demonstrated that decarbonation in the MnCO3–SiO2–Al2O3 system occurred at 870 ± 20 °C (3.0 GPa), 1070 ± 20 °C (6.3 GPa), and 1170 ± 20 °C (7.5 GPa). Main Raman spectroscopic modes of the synthesized spessartine were 349–350 (R), 552(υ2), and 906–907 (υ1) 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 + CO2 can occur at conditions close to those of a hot subduction P-T path but are 300–350 °C lower than pyrope + CO2 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.

Energy Dispersive Diffraction in a Diamond Anvil High Pressure Cell Using Synchrotron and Conventional X-Radiation

1983 ◽  
Vol 27 ◽  
pp. 331-337
Author(s):  
David R. Black ◽  
Carmen S. Menoni ◽  
Ian L. Spain
Keyword(s):  
High Pressure ◽  
Energy Dispersive ◽  
X Rays ◽  
High Pressure Cell ◽  
X Ray ◽  
Detection Techniques ◽  
Wide Range ◽  
Diamond Anvil ◽  
Experimental Geometry ◽  
Energy Dispersive Diffraction

A wide range of structural studies have been carried out in high pressure diamond anvil cells using x-rays. The most common experimental geometry is shown in Fig. 1a. The incident x-ray beam passes axially through the first diamond and enters the sample, typically 100-300 μm in diameter and 20-100 μm thick; the diffracted x-rays exit via the second diamond. Energy-dispersive detection techniques (EDXRD) have been used. However the intensity of diffracted radiation from the sample is weak, so that typical exposure times with a conventional, fixed anode, x-ray source are typically one to several days.Accordingly, higher intensity radiation from synchrotron sources has been used for these experiments.

scholarly journals Experimental Study of Surface Etching in Synthetic Diamond Microcrystals due to Presence of Cu and Fe at High Pressure

2020 ◽  
pp. 18-21
Author(s):  
I.A. Ishutin ◽  
A.A. Chepurov ◽  
E.I. Zhimulev
Keyword(s):  
Experimental Study ◽  
High Pressure ◽  
Synthetic Diamond ◽  
Close Contact ◽  
High Pressure Cell ◽  
Diamond Composite ◽  
Refractory Oxides ◽  
Diamond Crystals ◽  
Composite Diamond ◽  
High Pressure Apparatus

In the present work, microcrystals of synthetic diamond extracted from a metal-diamond composite were investigated. A composite based on Cu and Fe was obtained by sintering at a pressure of 4 GPa and a temperature of1300 °C. The experiments were carried out using a split-sphere high-pressure apparatus BARS. The high-pressure cell was made of refractory oxides ZrO2, CaO, and MgO using a tubular graphite heater. In the composite, diamond grains were in close contact with neighboring diamonds, and the metal phase filled the interstices. The study of the diamond crystals demonstrated the appearance of newly formed micromorphological structures on the surfaces in the form of numerous cavities of irregular shape on the faces of octahedron, as well as pyramids on the faces of cube, the morphological elements of which follow the contours of the cube face of the diamond. Thus, the results of the work evidence for the processes of etching of the diamond crystals during the experiments, which is associated with the presence of metallic iron in the composite. This type of etching forms a roughly cavernous surface on the diamond crystals, which can be considered as an additional factor for improving the metal-diamond bond in copper-based composites.

scholarly journals HIGH PRESSURE APPARATUS FOR TRANSPORT PROPERTIES STUDY IN HIGH MAGNETIC FIELD

2002 ◽  
Vol 16 (20n22) ◽  
pp. 3330-3333 ◽  
Author(s):  
F. HONDA ◽  
V. SECHOVSKÝ ◽  
O. MIKULINA ◽  
J. KAMARÁD ◽  
A. M. ALSMADI ◽  
...  
Keyword(s):  
Magnetic Field ◽  
High Pressure ◽  
Hydrostatic Pressure ◽  
Transport Properties ◽  
High Magnetic Field ◽  
Electrical Transport ◽  
Low Temperatures ◽  
Electrical Transport Properties ◽  
High Pressure Cell ◽  
High Pressure Apparatus

We have designed a high pressure apparatus for measuring electrical-transport properties at low temperatures, high magnetic field and hydrostatic pressure up to 10 kbar. Details of the high-pressure cell and an exemplary study on UNiAl are described and discussed briefly.

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
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