The experimental study on the melting of potassic basalt and eclogite with about 2% waterat 800-1300℃ and 1.0-3.5 GPa shows that the solidi of both rocks are significantly lower thanthose obtained from the previous e...The experimental study on the melting of potassic basalt and eclogite with about 2% waterat 800-1300℃ and 1.0-3.5 GPa shows that the solidi of both rocks are significantly lower thanthose obtained from the previous experiments of the same type of rocks under dry conditions,and the former which is enriched in potassium has a lower melting point than the latter. It is con-sistent with the previous study. The melting temperature of eclogite increases with pressure,whereas potassic basalt has similar properties only at 1.5—2.5 GPa and>3.0 GPa, and at 2.5—3.0 GPa the melting temperature decreases with pressure. This can be explained as follows: (1)eclogite only has one hydrous mineral amphibole and the dehydous temperature is lower than thewet solidus of the rock. (2) Amphibole exists in potassic basalt at the pressures lower than 2.5GPa and phlogopite exists at pressures higher than 2.5 GPa, and the special compositions of bothminerals determine that amphibole has a dehydration temperature higher than or close to that ofthe wet solidus of the rocks, while phlogopite has a dehydration temperature lower than that ofthe wet solidus. On the other hand the features of the continuous solidus in the experiment ofhydrous eclogite were produced by the fact that the dehydration temperature of its amphibolelower than or close to the melting temperature of the hydrous conditions. So the melting tempera-ture lowers at higher pressures. Therefore, the composition of the rocks in the lithosphere and thetypes of hydrous minerals and their stable P-T conditions are the important factors controllingthe solidi of rocks. It can quite well explain the partial melting of rocks and the origin of the lowvelocity zone in the deep lithosphere.展开更多
In order to investigate the mechanism of formation of abiogenetic hydrocarbons at the depth of the Earth, experimental research on reactions between carbonates and water or water bearing minerals was carried out at th...In order to investigate the mechanism of formation of abiogenetic hydrocarbons at the depth of the Earth, experimental research on reactions between carbonates and water or water bearing minerals was carried out at the pressure of about 1 GPa and the temperature range of 800-1500℃. The reactions took place in an open and nonequilibrium state. Chromatographic analyses of the gas products indicate that in the experiments there were generated CH 4 dominated hydrocarbons, along with some CO 2 and CO. Accordingly, we think there is no essential distinction between free state water and hydroxy in the minerals in the process of hydrocarbon formation. This study indicates that reactions between carbonates and water or water bearing minerals should be an important factor leading to the formation of abiogenetic hydrocarbons at the Earth’s depth.展开更多
The purpose of this study was to enhance the content of valuable metals, such as Au, Ag, and Te, in tellurium-bearing minerals via bioleaching. The ore samples composed of invisible Au and Au paragenesis minerals(such...The purpose of this study was to enhance the content of valuable metals, such as Au, Ag, and Te, in tellurium-bearing minerals via bioleaching. The ore samples composed of invisible Au and Au paragenesis minerals(such as pyrite, chalcopyrite, sphalerite and galena) in combination with tellurium-bearing minerals(hessite, sylvanite and Tellurobismuthite) were studied. Indigenous microbes from mine drainage were isolated and identified as Acidithiobacillus ferrooxidans, which were used in bioleaching after adaption to copper. The effect of the microbial adaption on the bioleaching performance was then compared with the results produced by the non-adaptive process. The microbial adaption enhanced the Au–Ag–Te contents in biological leaching of tellurium-bearing ore minerals. This suggests that bioleaching with adapted microbes can be used both as a pretreatment and in the main recovery processes of valuable metals.展开更多
The tectonic development of the Tarim block has experienced four stages, i. e. Earth's core accretion and block formation in the Precambrian, margin splitting, opening-closing and piecing up in the Early Palaeozoi...The tectonic development of the Tarim block has experienced four stages, i. e. Earth's core accretion and block formation in the Precambrian, margin splitting, opening-closing and piecing up in the Early Palaeozoic, rift formation and plate unification in the Late Palaeozoic, and basin-mountain coupling and landform shaping in the Meso-Cenozoic, forming six ore-bearing formations and ore deposits of various genetic types in the Tianshan Mountains, Kunlun Mountains and Altun Mountains. In the peripheral areas of Tarim there are four giant intercontinental metallogenic belts passing through, the Central Tianshan and southwestern Tianshan belts in the former USSR and the Qinling-Qilian-Kunlun and Palaeo-Tethys belts in China. According to the macro-analysis on the nearly one thousand known deposits (occurrences) and geophysical-geochemical anomalies, and the information from reconnaissance in some areas, the region has very good prospects for mineral resources. Some of the metallogenic belts may well become the reserve bases for exploration of mineral resources in China.展开更多
Lanmuchangite is a new thallium hydrous sulfate from the oxidation zone hosting rich thallium ore bodies in the Lanmuchang thallium(mercury) ore deposit, Xinren County, Guizhou Province, China. This new mineral is nam...Lanmuchangite is a new thallium hydrous sulfate from the oxidation zone hosting rich thallium ore bodies in the Lanmuchang thallium(mercury) ore deposit, Xinren County, Guizhou Province, China. This new mineral is named after the locality where it was discovered. The mineral is associated with melanterite, pickeringite, potassium alum, jarosite, gypsum, arsenic blane, sulphur and some unknown minerals. The aggregates of lanmuchangite range from 2 to 10 mm in size. In general, the aggregates are compact and massive in form and are composed of anhedral granular crystals measuring in size from 40 to 90μm, but the single crystal grains show distinct boundaries. Parallel columnar aggregates are occasionally seen, which are composed of subhedral to euhedral columnar crystals ranging in size from 15 to 65μm. White, light yellow to white in color, glassy in luster and transparent. Hv-{mess.}=94-124 kg/mm+2, Hm={3.1}-{3.4}, density={2.22} g/cm+3. Under the polarization microscope the mineral is colorless and homogeneous, with N-{meas.}={1.495}. It is easily water-soluble. The average chemical composition is: Tl-2O={33.25}, Al-2O-3={8.07}, SO-3={25.19}, SiO-2={0.10}, K-2O={0.35}, CaO={0.08}, MgO={0.06}, FeO={0.04} and H-2O={33.46} [the crystal water (H-2O) was measured by thermogravimetery (TG) while the other composition were determined by electron microprobe], totaling {100.60%}. The empirical formula is (Tl-{1.00}K-{0.05})-{1.05} (Al-{1.01}Si-{0.01}Ca-{0.01}Mg-{0.01})-{1.04}-{2.01}·{11.88} H-2O and the simplified formula is TlAl-2·12H-2O. The compatibility of lanmuchangite is {-0.03} and its value falls within the range of {±0.020}-{±0.039}, so the compatibility is excellent. Its TG curve demonstrated that the crystal water was lost (i.e., dewatering) in stages at 101, 130 and 230℃. At the temperature of 243℃ the process of dewatering came to the end and the sum of lost crystal water reaches {33.30} wt%. IR spectroscopic analysis showed that the absorption bands 3374-3147 cm+{-1} and 1655-1648 cm+{-1} are due to tensile and bending vibration of crystal water molecules (H-2O) whereas those at 1131 cm+{-1} and 605 cm+{-1} are attributed to tensile and bending vibration of group +{2-}. Lanmuchangite is of the isometric system, with space group=Pa3, a={12.212(5)}, v=1821(2)+3, and Z=4. The strongest diffraction lines from the X-ray power diffraction data are {4.314}(100, 220), {2.801}(70, 331), {7.03}(54, 111), {2.731}(35, 420), {6.11}(27, 200), {3.524}(24, 222), {3.676}(22, 311), {3.051}(22, 400), {2.350}(21, 511), {3.263}(20, 321), {2.494}(20, 422), {1.932}(19, 620).展开更多
The reconstruction of paleo-elevation serves a dual purpose to enhance our comprehension of geodynamic processes affecting terrestrial landforms and to contribute significantly to the interpretation of atmospheric cir...The reconstruction of paleo-elevation serves a dual purpose to enhance our comprehension of geodynamic processes affecting terrestrial landforms and to contribute significantly to the interpretation of atmospheric circulation and biodiversity.The oxygen(δ~(18)O_w)and deuterium(δD_w)isotopes in atmospheric precipitation are systematically depleted with the increase of altitude,which are typical and widely applicated paleo-altimeters.The utilization of hydrogen isotope of hydrous silicate minerals within the shear zone system,volcanic glass,and plant leaf wax alkanes offers valuable insights for addressing evaporation and diagenesis.In this paper,we review the principle,application conditions,and influencing factors of the hydrogen isotope paleo-altimeter.In addition,we discuss the feasibility of utilizing this technique for quantitatively estimating the paleo-elevation of the southeastern Tibetan Plateau,where multiple shear zones extend over hundred kilometers parallel to the topographic gradient.展开更多
基金Note:This study was supported by China National Natural Science Foundation Grant No.49070087.
文摘The experimental study on the melting of potassic basalt and eclogite with about 2% waterat 800-1300℃ and 1.0-3.5 GPa shows that the solidi of both rocks are significantly lower thanthose obtained from the previous experiments of the same type of rocks under dry conditions,and the former which is enriched in potassium has a lower melting point than the latter. It is con-sistent with the previous study. The melting temperature of eclogite increases with pressure,whereas potassic basalt has similar properties only at 1.5—2.5 GPa and>3.0 GPa, and at 2.5—3.0 GPa the melting temperature decreases with pressure. This can be explained as follows: (1)eclogite only has one hydrous mineral amphibole and the dehydous temperature is lower than thewet solidus of the rock. (2) Amphibole exists in potassic basalt at the pressures lower than 2.5GPa and phlogopite exists at pressures higher than 2.5 GPa, and the special compositions of bothminerals determine that amphibole has a dehydration temperature higher than or close to that ofthe wet solidus of the rocks, while phlogopite has a dehydration temperature lower than that ofthe wet solidus. On the other hand the features of the continuous solidus in the experiment ofhydrous eclogite were produced by the fact that the dehydration temperature of its amphibolelower than or close to the melting temperature of the hydrous conditions. So the melting tempera-ture lowers at higher pressures. Therefore, the composition of the rocks in the lithosphere and thetypes of hydrous minerals and their stable P-T conditions are the important factors controllingthe solidi of rocks. It can quite well explain the partial melting of rocks and the origin of the lowvelocity zone in the deep lithosphere.
文摘In order to investigate the mechanism of formation of abiogenetic hydrocarbons at the depth of the Earth, experimental research on reactions between carbonates and water or water bearing minerals was carried out at the pressure of about 1 GPa and the temperature range of 800-1500℃. The reactions took place in an open and nonequilibrium state. Chromatographic analyses of the gas products indicate that in the experiments there were generated CH 4 dominated hydrocarbons, along with some CO 2 and CO. Accordingly, we think there is no essential distinction between free state water and hydroxy in the minerals in the process of hydrocarbon formation. This study indicates that reactions between carbonates and water or water bearing minerals should be an important factor leading to the formation of abiogenetic hydrocarbons at the Earth’s depth.
文摘The purpose of this study was to enhance the content of valuable metals, such as Au, Ag, and Te, in tellurium-bearing minerals via bioleaching. The ore samples composed of invisible Au and Au paragenesis minerals(such as pyrite, chalcopyrite, sphalerite and galena) in combination with tellurium-bearing minerals(hessite, sylvanite and Tellurobismuthite) were studied. Indigenous microbes from mine drainage were isolated and identified as Acidithiobacillus ferrooxidans, which were used in bioleaching after adaption to copper. The effect of the microbial adaption on the bioleaching performance was then compared with the results produced by the non-adaptive process. The microbial adaption enhanced the Au–Ag–Te contents in biological leaching of tellurium-bearing ore minerals. This suggests that bioleaching with adapted microbes can be used both as a pretreatment and in the main recovery processes of valuable metals.
文摘The tectonic development of the Tarim block has experienced four stages, i. e. Earth's core accretion and block formation in the Precambrian, margin splitting, opening-closing and piecing up in the Early Palaeozoic, rift formation and plate unification in the Late Palaeozoic, and basin-mountain coupling and landform shaping in the Meso-Cenozoic, forming six ore-bearing formations and ore deposits of various genetic types in the Tianshan Mountains, Kunlun Mountains and Altun Mountains. In the peripheral areas of Tarim there are four giant intercontinental metallogenic belts passing through, the Central Tianshan and southwestern Tianshan belts in the former USSR and the Qinling-Qilian-Kunlun and Palaeo-Tethys belts in China. According to the macro-analysis on the nearly one thousand known deposits (occurrences) and geophysical-geochemical anomalies, and the information from reconnaissance in some areas, the region has very good prospects for mineral resources. Some of the metallogenic belts may well become the reserve bases for exploration of mineral resources in China.
文摘Lanmuchangite is a new thallium hydrous sulfate from the oxidation zone hosting rich thallium ore bodies in the Lanmuchang thallium(mercury) ore deposit, Xinren County, Guizhou Province, China. This new mineral is named after the locality where it was discovered. The mineral is associated with melanterite, pickeringite, potassium alum, jarosite, gypsum, arsenic blane, sulphur and some unknown minerals. The aggregates of lanmuchangite range from 2 to 10 mm in size. In general, the aggregates are compact and massive in form and are composed of anhedral granular crystals measuring in size from 40 to 90μm, but the single crystal grains show distinct boundaries. Parallel columnar aggregates are occasionally seen, which are composed of subhedral to euhedral columnar crystals ranging in size from 15 to 65μm. White, light yellow to white in color, glassy in luster and transparent. Hv-{mess.}=94-124 kg/mm+2, Hm={3.1}-{3.4}, density={2.22} g/cm+3. Under the polarization microscope the mineral is colorless and homogeneous, with N-{meas.}={1.495}. It is easily water-soluble. The average chemical composition is: Tl-2O={33.25}, Al-2O-3={8.07}, SO-3={25.19}, SiO-2={0.10}, K-2O={0.35}, CaO={0.08}, MgO={0.06}, FeO={0.04} and H-2O={33.46} [the crystal water (H-2O) was measured by thermogravimetery (TG) while the other composition were determined by electron microprobe], totaling {100.60%}. The empirical formula is (Tl-{1.00}K-{0.05})-{1.05} (Al-{1.01}Si-{0.01}Ca-{0.01}Mg-{0.01})-{1.04}-{2.01}·{11.88} H-2O and the simplified formula is TlAl-2·12H-2O. The compatibility of lanmuchangite is {-0.03} and its value falls within the range of {±0.020}-{±0.039}, so the compatibility is excellent. Its TG curve demonstrated that the crystal water was lost (i.e., dewatering) in stages at 101, 130 and 230℃. At the temperature of 243℃ the process of dewatering came to the end and the sum of lost crystal water reaches {33.30} wt%. IR spectroscopic analysis showed that the absorption bands 3374-3147 cm+{-1} and 1655-1648 cm+{-1} are due to tensile and bending vibration of crystal water molecules (H-2O) whereas those at 1131 cm+{-1} and 605 cm+{-1} are attributed to tensile and bending vibration of group +{2-}. Lanmuchangite is of the isometric system, with space group=Pa3, a={12.212(5)}, v=1821(2)+3, and Z=4. The strongest diffraction lines from the X-ray power diffraction data are {4.314}(100, 220), {2.801}(70, 331), {7.03}(54, 111), {2.731}(35, 420), {6.11}(27, 200), {3.524}(24, 222), {3.676}(22, 311), {3.051}(22, 400), {2.350}(21, 511), {3.263}(20, 321), {2.494}(20, 422), {1.932}(19, 620).
基金supported by the National Key Research and Development program of China(Grant No.2021YFC3000604)National Natural Science Foundation of China(Grant Nos.42030305,42272257)sponsored by State Key Laboratory of Earthquake Dynamics,Institute of Geology,China Earthquake Administration(Grant No.LED2022B04)。
文摘The reconstruction of paleo-elevation serves a dual purpose to enhance our comprehension of geodynamic processes affecting terrestrial landforms and to contribute significantly to the interpretation of atmospheric circulation and biodiversity.The oxygen(δ~(18)O_w)and deuterium(δD_w)isotopes in atmospheric precipitation are systematically depleted with the increase of altitude,which are typical and widely applicated paleo-altimeters.The utilization of hydrogen isotope of hydrous silicate minerals within the shear zone system,volcanic glass,and plant leaf wax alkanes offers valuable insights for addressing evaporation and diagenesis.In this paper,we review the principle,application conditions,and influencing factors of the hydrogen isotope paleo-altimeter.In addition,we discuss the feasibility of utilizing this technique for quantitatively estimating the paleo-elevation of the southeastern Tibetan Plateau,where multiple shear zones extend over hundred kilometers parallel to the topographic gradient.
