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Experimental data about Tremolite

In situ decarbonation kinetics of calcite were investigated at high temperatures, up to 900 °C, using synchrotron radiation powder X-ray diffraction. The sequence of X-ray diffraction spectra reveals that calcite begins to thermally decompose into lime (CaO) and CO2 at 800 °C and ambient pressure. The decarbonation degree gradually increases with temperature, and calcite completely transforms into lime at 900 °C. The kinetic analysis of the isothermal data using an Avrami model involving nucleation and growth yields the values for the decarbonation rate and reaction order. Our results indicate that the decarbonation rate increases from 2.89 × 10–4s–1 to 3.48 × 10–3s–1 with elevated temperature from 840 to 880 °C, showing a positive temperature dependence on the reaction rate. The calculated Avrami exponent (n) values between 1.35 and 2.38 suggest that the thermal decomposition of calcite should be mainly dominated by homogeneous nucleation and CO2 diffusion-controlled growth. In natural carbonate fault rocks, the decarbonation of CaCO3 caused by frictional heating may be strengthened by the action of high shear velocity. In addition, the resulting ultrafine powder and CO2 pressurization can remarkably reduce the friction coefficient between two fault planes, which further leads to carbonate fault weakening. The yielding result will be conductive to better understanding the role of decarbonation of calcite in some active fault zones.

Data for elastic properties of eclogite

Data for elastic properties of eclogite

Data for thermal conductivity and thermal diffusivity of tremolite

Data for elastic properties of eclogite

Background As a natural process of aging, intervertebral disc degeneration is more prone to degeneration, with limited repair ability, which is closely related to ageing and excessive manual labor. The main manifestations include the formation of fissures in the annulus fibrosus, the reduction of water in the intervertebral disc, and the decrease of elasticity. However, the molecular mechanism of intervertebral disc degeneration is still unclear. Methods In this study, key biomarkers in intervertebral disc degeneration were identified through bioinformatics. GSE70362 and GSE56081 were downloaded from the GEO database, and then the two datasets were differentially analyzed and validated for their expression, immune infiltration analysis, functional enrichment analysis, and potential drug prediction through the Connectivity Map (CMap) database. Results A total of 352 and 9815 differential genes were identified by GSE70362, GSE56081, respectively. The up-regulated and down-regulated genes of the two datasets were intersected with ferroptosis genes to obtain five key genes that were significantly correlated with immune cell content, namely AKR1C3, CKB, KRT19, MT1G and MUC1. The ROC results showed that the five core genes could well predict the occurrence and development of the disease. In addition, the results of CMap suggested that four drugs, including 1-Phenylbiguanide, LY-2183240, Flubendazole and Penciclovir, have the potential to reverse intervertebral disc degeneration. Conclusion Exploring the expression levels of five key genes in intervertebral disc degeneration is conductive to providing new ideas for the prevention and treatment of intervertebral disc degeneration. Moreover, Flubendazole and Penciclovir have the potential to provide options for clinical treatment of intervertebral disc degeneration.

Neurofilament light chain (NEFL) has been identified as a biomarker for spinal cord injury (SCI), but its effect and underlying mechanism in SCI remain unclear.SCI rat models were established for in vivo studies. Lipopolysaccharide (LPS)-induced cell models were used for in vitro studies. The protein and mRNA expression levels of genes were evaluated by western blotting and reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The pathological changes in rats after SCI were subjected to histological examinations. The interaction of NEFL and upstream miRNAs was explored using dual-luciferase reporter gene assays.NEFL was highly expressed in SCI rat spinal cord tissues and LPS-stimulated PC12 cells. NEFL silencing showed an inhibitory effect on the morphological changes of SCI rats and the secretion of inflammatory factors and facilitated functional recovery of SCI rats. MiR-30b-5p was demonstrated to target NEFL and negatively regulate NEFL mRNA and protein levels. Downregulation of miR-30b-5p in SCI cell and rat models was demonstrated. MiR-30b-5p alleviated the inflammatory response in SCI rat models and LPS-stimulated PC12 cells and promoted functional recovery in rats by targeting NEFL. NEFL activated mTOR signaling. MiR-30b-5p inactivated mTOR signaling by negatively regulating NEFL.MiR-30b-5p alleviated the inflammatory response and facilitated the functional recovery of SCI rats by targeting NEFL to inactivate the mTOR pathway.

Experimental data about garnet

Data for elastic properties of Ol-atg

We measured the electrical conductivity of tremolite over a range of pressures (1.0, 1.5, and 2.0 GPa) and temperatures (648–1373 K). At temperatures lower than 1173 K, the electrical conductivity of tremolite was ~ 0.001 S/m, but once the dehydroxylation reaction took place at 1173 K, we observed a significant increase in the electrical conductivity. The electrical conductivity continued to increase until it reached its maximum value of ~ 1 S/m at a temperature of 1373 K, which we attributed to dehydroxylation in the tremolite samples. The electrical behavior was altered by the physical breakdown of the tremolite structure, rather than the oxidation process. The decomposition of tremolite resulted in the creation of diopside, enstatite, and quartz. To explain some anomalous conductivity measurements, we propose that iron-free amphibole experiences a dehydroxylation mechanism that differs from the dehydroxylation mechanism observed in iron-bearing amphiboles. Our conductivity analyses indicate that the observed increase in the electrical conductivity in deep subduction regions (at depths of ~ 180 km) is driven by the dehydroxylation of tremolite and by the mixing of lherzolite and tremolite in the upper mantle. Using our data and previously published temperature gradient data, we were able to extrapolate reasonable electrical conductivity values for the surface and interior of Venus.

The non-isothermal decomposition kinetics of brucite under nitrogen atmosphere was studied using thermogravimetry and XRD techniques. The curves of mass loss with temperature implied that the first step of thermal decomposition took place at 300–400 °C, followed by a relatively slow process up to 600 °C. The initial decomposition temperature was significantly affected by heating rate, but it had no obvious influence on the total yield of water molecules. The apparent activation energies were calculated to be 144.29 kJ mol−1 to 148.82 kJ mol−1 in the given range of conversion, and the dependence of E on the extent of conversion indicated the existence of a consecutive process. The kinetic differential equation was established as dα/dT = (1.68 × 109/β) exp(− 1.70 × 104/T) (1 − α). The thermal decomposition could be described by first-order single reaction model for the main step, whereas it was dominated by the diffusion of water molecule at the mid-late stages.

In our study, a series of Raman experiments on the phase transition of calcite at high pressure and high temperature were investigated using a hydrothermal diamond anvil cell and Raman spectroscopy...

There are clear differences in the electrical conductivities of the crustal granites of the Qinghai-Tibet Plateau. Because these granites are among the major rock types on the Qinghai-Tibet Plateau, it is very important to detect the electrical conductivity of granites under high temperatures and pressures to study the electrical conductivity structure of this area. Using impedance spectroscopy at a frequency range of 10−1–106 Hz, the electrical conductivity of the muscovite-granite collected from Yadong was investigated at a confining pressure of 1.0 GPa and temperatures ranging from 577 to 996 K, while the electrical conductivity of the biotite-granite collected from Lhasa was investigated at a pressure of 1.0 GPa and temperatures ranging from 587 to 1382 K. The calculated activation enthalpies of the Yadong muscovite-granite sample is 0.92 eV in the low-temperature range (577–919 K) and 2.16 eV in the high-temperature range (919–996 K). The activation enthalpies of the Lhasa biotite-granite sample is 0.48 eV in the low-temperature range (587–990 K) and 2.06 eV in the high-temperature range (990–1382 K). The change in the activation enthalpies of the granites at different temperature ranges may be associated with the dehydration of the two samples. The electrical conductivities of the granite samples obtained in the laboratory using impedance spectroscopy correspond well with field observations conducted near the sampling points, both in terms of the actual conductivity values and the observed variations between the low-temperature and high-temperature regimes. This correlation of laboratory and field conductivities indicates that the conductivities of the crustal rocks in the two regions closely correspond to granite conductivities. We calculated the electrical conductivities of muscovite-granite and biotite-granite samples using the effective medium and HS boundary models. When applied to the crustal rocks of southern Tibet, the results of the geophysical conductivity profiles lie within the range of laboratory data. Thus, the electrical characteristics of the crustal rocks underlying the southern Qinghai-Tibet Plateau can largely be attributed to granites, with the large changes to high conductivities at increasing depths resulting from the dehydration of crustal rocks with granitic compositions.

The presented investigation explores the efficiency of novel transdermal drug delivery system of combination of two drugs i.e risedronate and alendronate in the treatment of osteoporosis. The nanoparticulate transdermal patch was prepared using PLGA as principle polymer which has been found to be suitable for drug delivery. The novel formulation system was found to be more efficient in lowering and maintaining the plasma calcium at a normal level when compared to a pure drug in a study carried out on an excised rat skin.

In this study, we introduce the application of data mining to petroleum exploration and development to obtain high-performance predictive models and optimal classifications of geology, reservoirs, reservoir beds, and fluid properties. Data mining is a practical method for finding characteristics of, and inherent laws in massive multi-dimensional data. The data mining method is primarily composed of three loops, which are feature selection, model parameter optimization, and model performance evaluation. The method’s key techniques involve applying genetic algorithms to carry out feature selection and parameter optimization and using repeated cross-validation methods to obtain unbiased estimation of generalization accuracy. The optimal model is finally selected from the various algorithms tested. In this paper, the evaluation of water-flooded layers and the classification of conglomerate reservoirs in Karamay oil field are selected as case studies to analyze comprehensively two important functions in data mining, namely predictive modeling and cluster analysis. For the evaluation of water-flooded layers, six feature subset schemes and five distinct types of data mining methods (decision trees, artificial neural networks, support vector machines, Bayesian networks, and ensemble learning) are analyzed and compared. The results clearly demonstrate that decision trees are superior to the other methods in terms of predictive model accuracy and interpretability. Therefore, a decision tree-based model is selected as the final model for identifying water-flooded layers in the conglomerate reservoir. For the reservoir classification, the reservoir classification standards from four types of clustering algorithms, such as those based on division, level, model, and density, are comparatively analyzed. The results clearly indicate that the clustering derived from applying the standard K-means algorithm, which is based on division, provides the best fit to the geological characteristics of the actual reservoir and the greatest accuracy of reservoir classification. Moreover, the internal measurement parameters of this algorithm, such as compactness, efficiency, and resolution, are all better than those of the other three algorithms. Compared with traditional methods from exploration geophysics, the data mining method has obvious advantages in solving problems involving calculation of reservoir parameters and reservoir classification using different specialized field data. Hence, the effective application of data mining methods can provide better services for petroleum exploration and development.

We performed an in situ dehydroxylation kinetics study of brucite under water-saturated conditions in the pressure and temperature ranges of 593–633 K and 668–1655 MPa using a hydrothermal diamond anvil cell. The kinetic analysis of the isothermal–isobaric data using an Avrami-type model involving nucleation and growth processes yields values for the dehydroxylation rate and reaction order compatible with a reaction mechanism limited by the monodimensional diffusion of water molecules from structural OH groups. Our results show a negative pressure dependence on the reaction rate k and a positive temperature dependence on the k. The dehydroxylation of brucite yields an activation volume ∆V value of 5.03 cm3/mol. Following the Arrhenius relationship, the apparent activation energy E a of the process is calculated to be 146 kJ/mol within the experimental P–T ranges. It is determined that the fluid production rates varying from 4.4 × 10−7 to 10.7 × 10−7 $${\text{m}}_{\text{fluid}}^{3} \;{\text{m}}_{\text{rock}}^{ - 3} \;{\text{s}}^{ - 1}$$ are a few orders of magnitude greater than the strain rate of the mantle serpentinites, which may be fast enough to result in the brittle fracture of rocks. Moreover, the rate of fluid production will be enhanced when brucite occurs in the non-/low H2O environments of the subduction zone.

A kinetic study of phase transformation of n-octane has been performed using a hydrothermal diamond anvil cell. The results show that pressure has a negative effect on the solid–liquid reaction rate. The increase of pressure can accelerate the liquid–solid transformation rate. Upon the liquid–solid transformation, the light transmittance showed a decreased trend with time in the early stage, which was caused by the formation of a large quantity of crystal nuclei. In the later stage, the light transmittance almost remained the same, thus indicating a growth stage of crystal nuclei. The activation volume yields a value of 2.16×10−5 and –1.35×10−5 m3/mol for the solid–liquid and liquid–solid transformations. Based on the obtained activation energy, the solid–liquid transformation is dominated by the interfacial reaction and diffusion, and the liquid–solid transformation is controlled by diffusion. This technique is an effective and powerful tool for the transformation kinetics study of n-octane.

The dehydration kinetics of natural talc were studied using thermogravimetric analyses (TGA). The dehydration rate of talc increases with decreasing grain size, but there is little effect on the dehydration rate when the grain size is less than 5 μm. The dehydration reaction of talc occurs in the temperature range 1103–1323 K; the thermal decomposition of talc yields enstatite and quartz plus water. The probable reaction mechanism for the dehydration of talc is an approximately second-order reaction, whose differential and integral rate expressions are f ( α ) = ( 1 − α ) n and G ( α ) = ( 1 − ( 1 − α ) ( 1 − n ) ) / ( 1 − n ) , respectively. The value of the reaction order n is 1.7, the activation energy E is 344 kJ/mol, and the pre-exponential factor α is 4.9 E12 s −1 . This dehydration reaction is probably a one-step reaction. The dehydration reaction is controlled by a heterogeneous mechanism. The relationship between the conversion rate of talc and time at different temperatures was obtained using the parameters derived from non-isothermal studies, and was used to predict the stability of talc at different temperatures.

An in situ dehydration kinetics study of gypsum under water-saturated condition was performed in the temperature and pressure ranges of 383–423 K and 343–1085 MPa by using a hydrothermal diamond anvil cell and Raman spectroscopy. Kinetic analysis shows that the dehydration rate k increases with pressure, suggesting a negative pressure dependence on dehydration rate. The elevation of temperature can contribute to the dehydration. The n values increase with pressure, indicating that the nucleation process becomes slower relative to the growth process. According to the n values of ∼1.0, the dehydration of gypsum is dominated by an instantaneous nucleation and diffusion-controlled growth mechanism. The obtained average activation volume ▵V is equal to 5.69 cm3/mol and the calculated activation energy Ea and the pre-exponential factor A are 66.9 kJ/mol and 4.66 × 105 s−1. The activation energy may be dependent upon grain size, shape, temperature and pressure, and surrounding water.

High-temperature in situ X-ray powder diffraction patterns were used to study the dehydration kinetics of natural talc with a size of 10–15 µm. The talc was annealed from 1073 to 1223 K, and the variations in the characteristic peaks corresponding to talc with the time were recorded to determine the reaction progress. The decomposition of talc occurred, and peaks corresponding to talc and peaks corresponding to enstatite and quartz were observed. The enstatite and talc exhibited a topotactic relationship. The dehydration kinetics of talc was studied as a function of temperature between 1073 and 1223 K. The kinetics data could be modeled using an Avrami equation that considers nucleation and growth processesα=1−exp(−ktn),where n varies from 0.4 to 0.8. The rate constant (k) equation for the natural talc islnk=ln(3.2E+14)−366.5RT.The reaction mechanism for the dehydration of talc is a heterogeneous nucleation and growth mechanism.

The crystallization kinetics of γ-anhydrite was investigated in the temperature and pressure ranges of 373–473 K and 1094–1903 MPa using a hydrothermal diamond anvil cell (HDAC) and Raman spectroscopy. A calcium sulfate solution was formed by dissolving gypsum in water at high pressure, and γ-anhydrite crystallized due to the increasing temperature. The relationship among the reaction rate, k , the temperature, T , and the pressure, P was established as k =−1.75×10 −3 +1.83×10 −6 P +3.57×10 −7 T , with an R 2 value of 0.943, of which the applicable range is 373 K≤ T ≤473 K and 1196 MPa≤ P ≤1903 MPa. An elevation of T or P will accelerate the crystallization rate of γ-anhydrite. The time exponent n obtained between 0.96 and 1.29 indicates that the process of crystallization should be controlled by instant nucleation on the grain boundary and diffusion controlled growth. In the process of crystallization, the volume is reduced because of the decrease of pressure, and the volume change Δ V is equal to −6.05×10 −6 m 3 /mol. The calculated activation energy E a is 10.7 kJ/mol, and the pre-exponential factor A is 2.27×10 −2 s −1 .

Regions with high electrical conductivities in subduction zones have attracted a great deal of attention. Determining the exact origin of these anomalies could provide critical information about the water storage and cycling processes during subduction. Antigorite is the most important hydrous mineral within deep subduction zones. The dehydration of antigorite is believed to cause high-conductivity anomalies. To date, the effects of dehydration on the electrical conductivity of antigorite remain poorly understood. Here, we report new measurements of the electrical conductivity of both natural and hot-pressed antigorite at pressures of 4 and 3 GPa, respectively, and at temperatures reaching 1073 K. We observed significantly enhanced conductivities when the antigorite was heated to temperatures beyond its thermodynamic stability field. Sharp increases in the electrical conductivity occurred at approximately 848 and 898 K following the decomposition of antigorite to forsterite, enstatite and aqueous fluids. High electrical conductivities reaching 1 S/m can be explained by the presence of an interconnected network of conductive aqueous fluids. Based on these results for the electrical conductivity of antigorite, we conclude that high-conductivity regions associated with subduction zones can be attributed to dehydration-induced fluids and the formation of interconnected networks of aqueous fluids during the dehydration of antigorite.

The electrical conductivity of Tibetan eclogite was investigated at pressures of 1.5–3.5 GPa and temperatures of 500–803 K using impedance spectroscopy within a frequency range of 10−1–106 Hz. The electrical conductivity of eclogite increases with increasing temperature (which can be approximated by the Arrhenius equation), and is weakly affected by pressure. At each tested pressure, the electrical conductivity is weakly temperature dependent below ∼650 K and more strongly temperature dependent above ∼650 K. The calculated activation energies and volumes are 44±1 kJ/mol and −0.6±0.1 cm3/mol for low temperatures and 97±3 kJ/mol and −1.2±0.2 cm3/mol for high temperatures, respectively. When applied to the depth range of 45–100 km in Tibet, the laboratory data give conductivities on the order of 10−1.5–10−4.5 S/m, within the range of geophysical conductivity profiles.

[1] Presence of graphite is one of the mechanisms to explain enhanced electrical conductivity. Because the conductivity of graphite is highly anisotropic and the connectivity of graphite depends strongly on the geometry of the crystals, the key issue is the geometry of graphite in a rock including their crystallographic orientation and the shape of graphite crystals. We explored the role of graphite on electrical conductivity in olivine-rich aggregates. To obtain well-defined results, we conducted an experimental study at high pressure and temperature conditions. Olivine aggregates containing diamonds were annealed to transform diamond to graphite with nearly equilibrium morphology. Graphite formed by the transformation from diamond has thin disk-shape morphology, the plane being the highly conductive (0001) plane. When the concentration of graphite exceeds the percolation threshold (~ 1 wt%), electrical conductivity is significantly enhanced. Some of the observed high conductivity regions may represent regions of high concentration of graphite.

Electrical conductivity of talc was measured at 0.5 GPa and ~473 to ~1,300 K by using impedance spectroscopy both before and after dehydration. Before dehydration, the electrical conductivity of talc increased with temperature and is ~10−4 S/m at 1,078 K. After dehydration, most of the talc changed to a mixture of enstatite and quartz and the total water content is reduced by a factor 6 or more. Despite this large reduction in the total water content, the electrical conductivity increased. The activation enthalpy of electrical conductivity (~125 kJ/mol) is too large for the conduction by free water but is consistent with conduction by small polaron. Our results show that a majority of hydrogen atoms in talc do not enhance electrical conductivity, implying the low mobility of the hydrogen atoms in talc. The observed small increase in conductivity after dehydration may be attributed to the increase in oxygen fugacity that enhances conductivity due to small polaron.

We investigated the electrical conductivity of amphibole-bearing rocks under the conditions of the middle to lower crust. Alternating current measurements were performed in the frequency range of 10–106 Hz in a cubic-anvil high-pressure apparatus at 0.5–1.0 GPa and 373–873 K. The electrical conductivity of these rocks is weakly temperature dependent below ~800 K with modest anisotropy and relatively low conductivity (~5 × 10−3 S/m at ~750 K with the activation enthalpy of 64–67 kJ/mol). However, the electrical conductivity starts to increase with temperature more rapidly above ~800 K (activation enthalpy of 320–380 kJ/mol). The infrared spectroscopy observations indicate that dehydration occurs in this high temperature regime. The observed high activation enthalpy and the reproducibility suggest that the enhanced conductivity is not due to the direct effect caused by the generation of conductive fluids. Dehydration of amphibole is associated with the oxidation of iron (from ferrous to ferric), and we suggest that the increased conductivity associated with dehydration is caused by oxidation. This effect may explain high electrical conductivity observed in some regions of the continental crust.

The mobility of Cu2+, Zn2+, Ni2+, and Cd2+ in soils treated with red mud was experimentally studied to explore the feasibility of remediation of smelter-contaminated soils. Red mud samples were collected with the Bayer process (BRM) and confederate process (CRM) in the Aluminous Plant of Guizhou Province. Two farmed soil samples were collected from the Niujiaotang mining area, Guizhou Province, Southwest China. One sample was weakly polluted by fly ash; and the other was polluted severely by waste water from the smelter. For evaluating the potential of remediation, the concentrations of free metal ions and the distributions of metals in the soil were determined. The concentrations of free metal ions were measured by using the Donnan Membrane Technique, and the contributions of soil sorbents to the heavy metals adsorptions were calculated with Equilibrium Calculation of Speciation and Transport (ECOSAT). BRM reduced the concentrations of free metal ions in two kinds of soils, while CRM only favored the decrease of the concentrations of free metal ions in seriously contaminated soils. The experimental data also showed a tendency that the concentrations of free metal ions decreased proportionally with the amount of added red mud, which resulted from the increasing adsorption of heavy metal ions in the form of metal ion hydroxides.

The electrical conductivity of upper-mantle rocks—dunite, pyroxenite, and lherzolite—was measured at ∼2–3 GPa and ∼1,273–1,573 K using impedance spectra within a frequency range of 0.1–106 Hz. The oxygen fugacity was controlled by a Mo–MoO2 solid buffer. The results indicate that the electrical conductivity of lherzolite and pyroxenite are approximately half and one order of magnitude higher than that of dunite, respectively. A preliminary model involving water and iron content effects on the electrical conductivity was derived and is summarized by the relation: $$ \sigma = 10^{{5.2\,\pm\,0.4}} \,C^{{0.67\,\pm\,0.07}}_{W} \,\exp{\left( { - \frac{{(183\,\pm\,9){\text{kJ}}/{\text{mol}}}} {{RT}}} \right)}\,\exp {\left( {X\,\frac{{(79\, \pm\,3){\text{kJ}}/{\text{mol}}}} {{RT}}} \right)}.$$ The results also indicate that pyroxenes dominate the bulk conductivity of upper mantle in hydrous conditions and suggest the maximum water content in oceanic upper mantle is as high as ∼0.09 wt%.

The study of heavy metal speciation is of interest for the evaluation of their ecotoxicological risk. Free heavy metal ion concentrations of Cu2+, Zn2+, Ni2+ and Cd2+ were studied at different soil to soil solution ratio (SSR) to discuss metal bioavailability and toxicity in circumstance. The samples were collected from two farmed soils, impacted by a cadmium rich zinc deposit, Guizhou, China. One is near a bridge (QBT for short), which is 15 km away from smelter and is regarded as polluted by fly ash from smelter, the other is located 300 m away from a smelting factory (BXT for short), and it is polluted badly by waste water from smelter. To determine the free heavy metal ion concentration, Donnan Membrane Technique (DMT) and ECOSAT program were used. The concentrations of free copper and zinc ions in QBT and all studied metal ions in BXT were nearly in direct ratio with the soil to soil solution ratio, and they increased with the increasing of SSR. The variational trends of the concentrations of free nickel and cadmium ions in QBT were contrary to those of copper and zinc ions. The measured and predicted results were compared and they agreed with each other. Individual sorbents contribution to metal binding was also predicted. The results suggest soil organic matter is the most important sorbents in the two soils, and hydrous ferric oxide takes the second place.

In situ Raman measurements of barite were performed at temperatures in the range of 298–673 K and pressures in the range of 105–1217 MPa using a hydrothermal diamond anvil cell combined with laser Raman spectroscopy. The Raman frequency and the full width at half maximum (FWHM) of the most intense ν1 Raman peak for barite as a function of pressure and temperature were obtained. In the experimental P–T ranges, the ν1Raman band systematically shifted toward low wavenumbers with increasing pressure and temperature. The positive pressure dependence of ν1Raman frequency indicates stress-induced shortening of the S–O bond, whereas the negative temperature dependence shows temperature-induced expansion of the S–O bond. In contrast, the observed ν1Raman band became broadened, which should be attributed to the reduced ordering of molecular structure. Based on the obtained data, the established relationships among the Raman shift or the FWHM, pressure and temperature can be used to obtain good estimates of the internal pressure in natural barite-bearing fluid inclusions or hydrothermal diamond anvil cell. This is a sensitive and reliable approach to the accurate determination of geological pressure.

It is well known that water (as a source of hydrogen) affects the physical and chemical properties of minerals--for example, plastic deformation and melting temperature--and accordingly plays an important role in the dynamics and geochemical evolution of the Earth. Estimating the water content of the Earth's mantle by direct sampling provides only a limited data set from shallow regions (