Clay mineral analyses of the Middle Jurassic through the Early Cretaceous sedimentary rocks from the Guangyuan-Jian’ge section,Sichuan Basin (southwestern China)were undertaken in this article, which is aiming to rec...Clay mineral analyses of the Middle Jurassic through the Early Cretaceous sedimentary rocks from the Guangyuan-Jian’ge section,Sichuan Basin (southwestern China)were undertaken in this article, which is aiming to reconstruct the palaeoclimate of the area.Relative contents of the four clay minerals, smectite(25.8%-1.0%-46.8%),kaolinite(31.0%- 12.5%-12.6%),illite(31.3%-68.0%-28.0%)and chlorite(11.8%-8.5%-12.6%),as the target clay minerals,illite crystalline index(0.26-0.31-0.27)and chemical index(0.62-0.66-0.79)are used as indicator of paleoclimate.It is indicated that changes of展开更多
Linxia Basin is a late Cenozoic fault-block basin along the border between the Tibet plateau and the Loess plateau in Northwestern China. Its formation and sediments record may be directly affected by the structural d...Linxia Basin is a late Cenozoic fault-block basin along the border between the Tibet plateau and the Loess plateau in Northwestern China. Its formation and sediments record may be directly affected by the structural dynamics and the uplift of the Tibet Plateau. For this reason, we studied the mineral characteristics of the Maogou formation of Miocene sediments using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The XRD results showed that quartz, chlorite, illite, calcite, plagioclase, orthoclase, kaolinite, and trace palygorskite are present throughout the sequence of the cross-section in Linxia basin. In contrast, gypsum and ankerite occur occasionally in the upper portion of the Miocene deposits. The content of calcite varied with layers in the profile and was relatively concentrated in mudstone. Chlorite and illite were observed transforming into palygorskite under SEM observation. Based on the mineral characteristics and the change of mineral composition, especially the clay minerals, it could be inferred that an arid environment prevailed in the region with warm and cold intervals during Miocene time.展开更多
The clay mineralogy of the clay intervals interbedded with siliceous mudstones across the Permian-Triassic boundary (PTB) in Pengda, Guiyang, Guizhou province, was investigated by X-ray diffraction (XRD) and high reso...The clay mineralogy of the clay intervals interbedded with siliceous mudstones across the Permian-Triassic boundary (PTB) in Pengda, Guiyang, Guizhou province, was investigated by X-ray diffraction (XRD) and high resolution transmission electron microscopy (HRTEM). The clay mineral assemblages of the sediments are mainly I/S clays and minor smectite, kaolinite, and illite as reveled by XRD analyses. The peak-shape parameters BB1 and BB2 of I/S clays of the representative clay bed PL-01 are 4.7° and 4.4°, and the peak position of the low angle reflection is at 6.8° 2θ (13.6 ), suggesting that the I/S clays has a IS type of ordering. However, the presence of multi-order reflections and their intensities are different from those of completely ordered 1∶1 mixed-layer I/S clay rectorite, indicating that I/S clays of the Pengda section have partially ordered IS structures. HRTEM observations show that most of the I/S clays exhibit an IS stacking ordering. However, in some areas within a IS particle, smectite layer is observed in doublets, triplets, and quartets, which are interstratified by various amounts of illite layers, suggesting the presence of other irregular stacking in addition to the major 1∶1 IS ordered stacking. Transformation of smectite layer into illite layers is also observed in the I/S clays, suggesting that the Pengda I/S clays are derived from smectite illitization, in good agreement with the clay mineral assemblage. The I/S clays of the Pengda section contain up to 45% to 95% smectite layer, the notably higher contents of smectite layer relative to those of other PTB stratigraphic sets in south China can be attributed to difference in alteration and smectite illitization processes due to different sedimentary environments.展开更多
Understanding the adsorption behavior of heavy metals and metalloids on clay minerals is essential for remediating heavy metal-contaminated soils.The adsorption of heavy metals and metalloids on illite(001)and sodium ...Understanding the adsorption behavior of heavy metals and metalloids on clay minerals is essential for remediating heavy metal-contaminated soils.The adsorption of heavy metals and metalloids on illite(001)and sodium montmorillonite(Na-MMT)(001)surfaces was investigated using first-principles calculations in this study,especially As atom and H_(3)AsO_(3) molecule.The adsorption energies of the As atom were−1.94 eV on the illite(001)and−0.56 eV on the Na-MMT(001),whereas,the adsorption energies of the H_(3)AsO_(3) molecule were−1.40 eV on illite(001)and−1.01 eV on Na-MMT(001).The above results indicate that the adsorption was more energetically favorable on illite(001).Additionally,compared to Na-MMT(001),there were more significant interactions between the atoms/molecules on the illite(001).After As atom and H_(3)AsO_(3) molecule adsorption,the electrons were transferred from mineral surface atoms to the adsorbates on both illite(001)and Na-MMT(001)surfaces.Moreover,the adsorption of As atom on illite(001)and Na-MMT(001)surfaces were more energy favorable compared to Hg,Cd,and Cr atoms.Overall,this work provides new insights into the adsorption behavior of As atoms and As molecules on illite and Na-MMT.The results indicate that illite rich soils are more prone to contamination by arsenic compared to soils primarily composed of Na-MMT minerals.展开更多
Distribution of heavy, light and clay minerals in Late Pleistocene—Holocene deposits from different coastal environments (beaches, lagoons, dunes, relict lakes, ria bays and inlets, open inlets) was analysed. It was ...Distribution of heavy, light and clay minerals in Late Pleistocene—Holocene deposits from different coastal environments (beaches, lagoons, dunes, relict lakes, ria bays and inlets, open inlets) was analysed. It was established that mineralogical composition of coastal deposits was a result of provenance and its hypergenous changes, transformation of material within transit zone, and accumulative conditions of inshore zone. Contents of stable minerals increase in deposits of the inlets confined to mouths of the small streams and in horizons of the sections, formed during regressive phases. Unstable minerals amount is higher in deposits of inlets, confined to mouths of the large river. The clay mineral fraction of shelf sediments consists mostly of illite. Authigenous pyrites dominate in deposits of ria bays, lagoons and relict lakes, formed during transgressive phases. Volcanic glass, found in deposits, is product of Holocene eruptions of Baegdusan (Baitushen) Volcano.展开更多
A severe Asian Dust Storm(ADS)event occurred on April 16-17th,2006 in northem China.Mineral components of dust samples were analyzed using X-ray diffraction(XRD).The result indicates that dust particles were dominated...A severe Asian Dust Storm(ADS)event occurred on April 16-17th,2006 in northem China.Mineral components of dust samples were analyzed using X-ray diffraction(XRD).The result indicates that dust particles were dominated by quartz(37.4%)and clay (32.9%),followed by plagioclase(13.7%),with small amounts of calcite,K-feldspar,dolomite,homblende, and gypsum(all【10%).The clay fractions with diameter less than 2μm were separated from the展开更多
Because of the dispersion at the nanometer level, polymer-clay nanocomposites exhibit superior properties in comparison with pure polymer or conventional composites; this includes properties such as barrier properties...Because of the dispersion at the nanometer level, polymer-clay nanocomposites exhibit superior properties in comparison with pure polymer or conventional composites; this includes properties such as barrier properties , improved thermal stability and flame retardancy. The outstanding properties of polymer-clay nanocomposites are achieved at a much lower volume fraction, compared with conventional composites. Polymer-clay nanocomposites can be processed using common techniques, such as extrusion and casting, which are superior to the cumbersome techniques used for the conventional composites. Hence, polymer-clay nanocomposites have important potential commercial value.展开更多
There are many serious problems of the industrial wastewater cleaning in the mining and enriching industry caused by their great volumes.The current works are devoted to investigating actions of the natural and artifi...There are many serious problems of the industrial wastewater cleaning in the mining and enriching industry caused by their great volumes.The current works are devoted to investigating actions of the natural and artificial geochemical barriers to decrease toxic drainage waters from the sulphide-containing tailings.Belovs Zinc Plant(Kemerovo region,Russian Federation) tailing and natural(not modified) bentonitic clay from Kamalinskoe deposit(Krasno-展开更多
Geophagy is the deliberate consumption of earth materials such as soils,clays or sediments by human and animals.The ingested soil is chosen based on its physical,chemical,and mineralogical nature.Early studies reveal ...Geophagy is the deliberate consumption of earth materials such as soils,clays or sediments by human and animals.The ingested soil is chosen based on its physical,chemical,and mineralogical nature.Early studies reveal that geophagy functions through(1) adsorption/absorption of ingested toxic plant compounds onto clay particles,(2)mineral supplementation (Na,Mn,K,and S as the possible candidates),and(3)展开更多
Shale gas, which is derived from organic matters in shale and stored in shale deposits, is an important unconventional gas resource and attracts attention due to its significant requirement in the hydrocarbon producti...Shale gas, which is derived from organic matters in shale and stored in shale deposits, is an important unconventional gas resource and attracts attention due to its significant requirement in the hydrocarbon production. Methane (CH4) is the dominant component of shale gas, and adsorbed gas is an important reservoir form. Many studies have investigated the adsorption capacities and adsorption mechanisms of CH4 in shale. Organic matters and clay minerals have been proposed to be the two major components for CH4 adsorption. Adsorption of CH4 in organic matters, such as the adsorption capacity and effects of characteristics of the organic matters, has been well investigated. However, studies on CH4 adsorption on clay minerals have mainly focused on evaluating the adsorption capacity, and very little information about the adsorption mechanism has been provided. For example, the adsorption sites and factors influencing CH4 adsorption on clay minerals remain unclear. Three main reasons account for this: (1) the co-existence of organic matters in samples affects the evaluation of CH4 adsorption on clay minerals; (2) the pressures used during adsorption are not representative of actual reservoir pressures; and (3) the clay minerals selected have low swelling capacity and a smaller interlayer distances than a CH4 size, resulting in the misunderstanding of the CH4 adsorption sites.展开更多
文摘Clay mineral analyses of the Middle Jurassic through the Early Cretaceous sedimentary rocks from the Guangyuan-Jian’ge section,Sichuan Basin (southwestern China)were undertaken in this article, which is aiming to reconstruct the palaeoclimate of the area.Relative contents of the four clay minerals, smectite(25.8%-1.0%-46.8%),kaolinite(31.0%- 12.5%-12.6%),illite(31.3%-68.0%-28.0%)and chlorite(11.8%-8.5%-12.6%),as the target clay minerals,illite crystalline index(0.26-0.31-0.27)and chemical index(0.62-0.66-0.79)are used as indicator of paleoclimate.It is indicated that changes of
文摘Linxia Basin is a late Cenozoic fault-block basin along the border between the Tibet plateau and the Loess plateau in Northwestern China. Its formation and sediments record may be directly affected by the structural dynamics and the uplift of the Tibet Plateau. For this reason, we studied the mineral characteristics of the Maogou formation of Miocene sediments using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The XRD results showed that quartz, chlorite, illite, calcite, plagioclase, orthoclase, kaolinite, and trace palygorskite are present throughout the sequence of the cross-section in Linxia basin. In contrast, gypsum and ankerite occur occasionally in the upper portion of the Miocene deposits. The content of calcite varied with layers in the profile and was relatively concentrated in mudstone. Chlorite and illite were observed transforming into palygorskite under SEM observation. Based on the mineral characteristics and the change of mineral composition, especially the clay minerals, it could be inferred that an arid environment prevailed in the region with warm and cold intervals during Miocene time.
文摘The clay mineralogy of the clay intervals interbedded with siliceous mudstones across the Permian-Triassic boundary (PTB) in Pengda, Guiyang, Guizhou province, was investigated by X-ray diffraction (XRD) and high resolution transmission electron microscopy (HRTEM). The clay mineral assemblages of the sediments are mainly I/S clays and minor smectite, kaolinite, and illite as reveled by XRD analyses. The peak-shape parameters BB1 and BB2 of I/S clays of the representative clay bed PL-01 are 4.7° and 4.4°, and the peak position of the low angle reflection is at 6.8° 2θ (13.6 ), suggesting that the I/S clays has a IS type of ordering. However, the presence of multi-order reflections and their intensities are different from those of completely ordered 1∶1 mixed-layer I/S clay rectorite, indicating that I/S clays of the Pengda section have partially ordered IS structures. HRTEM observations show that most of the I/S clays exhibit an IS stacking ordering. However, in some areas within a IS particle, smectite layer is observed in doublets, triplets, and quartets, which are interstratified by various amounts of illite layers, suggesting the presence of other irregular stacking in addition to the major 1∶1 IS ordered stacking. Transformation of smectite layer into illite layers is also observed in the I/S clays, suggesting that the Pengda I/S clays are derived from smectite illitization, in good agreement with the clay mineral assemblage. The I/S clays of the Pengda section contain up to 45% to 95% smectite layer, the notably higher contents of smectite layer relative to those of other PTB stratigraphic sets in south China can be attributed to difference in alteration and smectite illitization processes due to different sedimentary environments.
基金Project(22376221)supported by the National Natural Science Foundation of ChinaProject(2024JJ2074)supported by the Natural Science Foundation of Hunan Province,ChinaProject(2023QNRC001)supported by the Young Elite Scientists Sponsorship Program by CAST。
文摘Understanding the adsorption behavior of heavy metals and metalloids on clay minerals is essential for remediating heavy metal-contaminated soils.The adsorption of heavy metals and metalloids on illite(001)and sodium montmorillonite(Na-MMT)(001)surfaces was investigated using first-principles calculations in this study,especially As atom and H_(3)AsO_(3) molecule.The adsorption energies of the As atom were−1.94 eV on the illite(001)and−0.56 eV on the Na-MMT(001),whereas,the adsorption energies of the H_(3)AsO_(3) molecule were−1.40 eV on illite(001)and−1.01 eV on Na-MMT(001).The above results indicate that the adsorption was more energetically favorable on illite(001).Additionally,compared to Na-MMT(001),there were more significant interactions between the atoms/molecules on the illite(001).After As atom and H_(3)AsO_(3) molecule adsorption,the electrons were transferred from mineral surface atoms to the adsorbates on both illite(001)and Na-MMT(001)surfaces.Moreover,the adsorption of As atom on illite(001)and Na-MMT(001)surfaces were more energy favorable compared to Hg,Cd,and Cr atoms.Overall,this work provides new insights into the adsorption behavior of As atoms and As molecules on illite and Na-MMT.The results indicate that illite rich soils are more prone to contamination by arsenic compared to soils primarily composed of Na-MMT minerals.
文摘Distribution of heavy, light and clay minerals in Late Pleistocene—Holocene deposits from different coastal environments (beaches, lagoons, dunes, relict lakes, ria bays and inlets, open inlets) was analysed. It was established that mineralogical composition of coastal deposits was a result of provenance and its hypergenous changes, transformation of material within transit zone, and accumulative conditions of inshore zone. Contents of stable minerals increase in deposits of the inlets confined to mouths of the small streams and in horizons of the sections, formed during regressive phases. Unstable minerals amount is higher in deposits of inlets, confined to mouths of the large river. The clay mineral fraction of shelf sediments consists mostly of illite. Authigenous pyrites dominate in deposits of ria bays, lagoons and relict lakes, formed during transgressive phases. Volcanic glass, found in deposits, is product of Holocene eruptions of Baegdusan (Baitushen) Volcano.
文摘A severe Asian Dust Storm(ADS)event occurred on April 16-17th,2006 in northem China.Mineral components of dust samples were analyzed using X-ray diffraction(XRD).The result indicates that dust particles were dominated by quartz(37.4%)and clay (32.9%),followed by plagioclase(13.7%),with small amounts of calcite,K-feldspar,dolomite,homblende, and gypsum(all【10%).The clay fractions with diameter less than 2μm were separated from the
基金Support by the Natural Science Foundation (51064006, 41272064) of ChinaGuangxi Science Foundation (2011GXNSFD 018008)Open Fund of Key Laboratory of Mineralogy and Metallogeny, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences (KLMM20110202)
文摘Because of the dispersion at the nanometer level, polymer-clay nanocomposites exhibit superior properties in comparison with pure polymer or conventional composites; this includes properties such as barrier properties , improved thermal stability and flame retardancy. The outstanding properties of polymer-clay nanocomposites are achieved at a much lower volume fraction, compared with conventional composites. Polymer-clay nanocomposites can be processed using common techniques, such as extrusion and casting, which are superior to the cumbersome techniques used for the conventional composites. Hence, polymer-clay nanocomposites have important potential commercial value.
文摘There are many serious problems of the industrial wastewater cleaning in the mining and enriching industry caused by their great volumes.The current works are devoted to investigating actions of the natural and artificial geochemical barriers to decrease toxic drainage waters from the sulphide-containing tailings.Belovs Zinc Plant(Kemerovo region,Russian Federation) tailing and natural(not modified) bentonitic clay from Kamalinskoe deposit(Krasno-
文摘Geophagy is the deliberate consumption of earth materials such as soils,clays or sediments by human and animals.The ingested soil is chosen based on its physical,chemical,and mineralogical nature.Early studies reveal that geophagy functions through(1) adsorption/absorption of ingested toxic plant compounds onto clay particles,(2)mineral supplementation (Na,Mn,K,and S as the possible candidates),and(3)
文摘Shale gas, which is derived from organic matters in shale and stored in shale deposits, is an important unconventional gas resource and attracts attention due to its significant requirement in the hydrocarbon production. Methane (CH4) is the dominant component of shale gas, and adsorbed gas is an important reservoir form. Many studies have investigated the adsorption capacities and adsorption mechanisms of CH4 in shale. Organic matters and clay minerals have been proposed to be the two major components for CH4 adsorption. Adsorption of CH4 in organic matters, such as the adsorption capacity and effects of characteristics of the organic matters, has been well investigated. However, studies on CH4 adsorption on clay minerals have mainly focused on evaluating the adsorption capacity, and very little information about the adsorption mechanism has been provided. For example, the adsorption sites and factors influencing CH4 adsorption on clay minerals remain unclear. Three main reasons account for this: (1) the co-existence of organic matters in samples affects the evaluation of CH4 adsorption on clay minerals; (2) the pressures used during adsorption are not representative of actual reservoir pressures; and (3) the clay minerals selected have low swelling capacity and a smaller interlayer distances than a CH4 size, resulting in the misunderstanding of the CH4 adsorption sites.
