Pub Date : 2023-01-01DOI: 10.1007/978-3-031-22327-3
Bhaskar Ghosh, D. Chakraborty
{"title":"Clay Minerals: Their Antimicrobial and Antitoxic Applications","authors":"Bhaskar Ghosh, D. Chakraborty","doi":"10.1007/978-3-031-22327-3","DOIUrl":"https://doi.org/10.1007/978-3-031-22327-3","url":null,"abstract":"","PeriodicalId":10311,"journal":{"name":"Clay Minerals","volume":"1 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50987334","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ji Zhou, Zuo-Hui Wang, Ana C. S. Alcântara, Yanhuai Ding
Abstract The adsorption mechanisms of hazardous gas molecules such as NH3, H2S and SO2 on sepiolite have not yet been elucidated. Therefore, molecular dynamics (MD) simulations were employed to investigate the adsorption behaviour of sepiolite towards NH3, H2S and SO2. A calculation model for sepiolite containing structural and zeolitic water molecules was constructed in this study. The adsorption sites and molecular configurations of the hazardous gases in the sepiolite channels were studied. The radial distribution function was employed to evaluate the interactions between the gas molecules and sepiolite. The results show that the order of adsorption capacity of sepiolite for the gases is as follows: SO2 > H2S > NH3. These three types of gas molecules absorbed in the channel nanopores of sepiolite exhibit different atomic configurations. The diffusion coefficients of the gas molecules in the channels decreased in the following order: NH3 > H2S > SO2. In addition, the diffusion coefficients were affected significantly by the ratio of the number of gas/water molecules. This study provides new perspectives for understanding the molecular processes responsible for the adsorption properties of sepiolite.
{"title":"Study of the adsorption mechanisms of NH3, H2S and SO2 on sepiolite using molecular dynamics simulations","authors":"Ji Zhou, Zuo-Hui Wang, Ana C. S. Alcântara, Yanhuai Ding","doi":"10.1180/clm.2022.22","DOIUrl":"https://doi.org/10.1180/clm.2022.22","url":null,"abstract":"Abstract The adsorption mechanisms of hazardous gas molecules such as NH3, H2S and SO2 on sepiolite have not yet been elucidated. Therefore, molecular dynamics (MD) simulations were employed to investigate the adsorption behaviour of sepiolite towards NH3, H2S and SO2. A calculation model for sepiolite containing structural and zeolitic water molecules was constructed in this study. The adsorption sites and molecular configurations of the hazardous gases in the sepiolite channels were studied. The radial distribution function was employed to evaluate the interactions between the gas molecules and sepiolite. The results show that the order of adsorption capacity of sepiolite for the gases is as follows: SO2 > H2S > NH3. These three types of gas molecules absorbed in the channel nanopores of sepiolite exhibit different atomic configurations. The diffusion coefficients of the gas molecules in the channels decreased in the following order: NH3 > H2S > SO2. In addition, the diffusion coefficients were affected significantly by the ratio of the number of gas/water molecules. This study provides new perspectives for understanding the molecular processes responsible for the adsorption properties of sepiolite.","PeriodicalId":10311,"journal":{"name":"Clay Minerals","volume":"58 1","pages":"1 - 6"},"PeriodicalIF":1.5,"publicationDate":"2022-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42594919","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Artificially coloured smectites (smectite pigments) were prepared via the sorption of anionic dyes on smectite saturated with ferric ions (Fe-smectite). Fe-smectite has a surface charge and is capable of decolourizing aqueous solutions containing single-component anionic dyes (Amaranth, Brilliant blue FCF and Tartrazine) or multi-component dyes (dye mixtures). Kinetic and equilibrium models were used to describe the sorption of individual dyes, whereas the decolourization of the multi-component system was studied by monitoring the reduction in the intensity of the absorption bands in the visible light region. The Langmuir–Freundlich dual-site model presented the best fit to the experimental data, and the sorption kinetics followed the pseudo-second order model. The smectite pigments were dispersed in colourless paint (10%, w/w), acting as organic–inorganic hybrid pigments. Colorimetric measurements of the powdered smectite pigments dispersed in colourless real-estate paint showed chemical compatibility without the need for solvents as dispersants. These properties allow the application of coloured smectites as pigments in a sustainable circular economy.
摘要采用阴离子染料在铁离子饱和蒙脱石（Fe-蒙脱石）上吸附制备了人工着色蒙脱石（蒙脱石颜料）。蒙脱石具有表面电荷，能够使含有单组分阴离子染料（Amaranth、Brilliant blue FCF和Tartrazine）或多组分染料（染料混合物）的水溶液脱色。动力学和平衡模型用于描述单个染料的吸附，而多组分系统的脱色则通过监测可见光区域吸收带强度的降低来研究。Langmuir–Freundlich双位点模型最符合实验数据，吸附动力学遵循伪二阶模型。蒙脱石颜料分散在无色涂料（10%，w/w）中，作为有机-无机杂化颜料。分散在无色房地产涂料中的粉末状蒙脱石颜料的比色测量表明，在不需要溶剂作为分散剂的情况下，具有化学兼容性。这些特性允许彩色蒙脱石作为颜料在可持续循环经济中的应用。
{"title":"Artificial colouration of smectite through adsorbing dyes from wastewater to make a hybrid pigment","authors":"I. A. Rodrigues, F. Anaissi","doi":"10.1180/clm.2022.34","DOIUrl":"https://doi.org/10.1180/clm.2022.34","url":null,"abstract":"Abstract Artificially coloured smectites (smectite pigments) were prepared via the sorption of anionic dyes on smectite saturated with ferric ions (Fe-smectite). Fe-smectite has a surface charge and is capable of decolourizing aqueous solutions containing single-component anionic dyes (Amaranth, Brilliant blue FCF and Tartrazine) or multi-component dyes (dye mixtures). Kinetic and equilibrium models were used to describe the sorption of individual dyes, whereas the decolourization of the multi-component system was studied by monitoring the reduction in the intensity of the absorption bands in the visible light region. The Langmuir–Freundlich dual-site model presented the best fit to the experimental data, and the sorption kinetics followed the pseudo-second order model. The smectite pigments were dispersed in colourless paint (10%, w/w), acting as organic–inorganic hybrid pigments. Colorimetric measurements of the powdered smectite pigments dispersed in colourless real-estate paint showed chemical compatibility without the need for solvents as dispersants. These properties allow the application of coloured smectites as pigments in a sustainable circular economy.","PeriodicalId":10311,"journal":{"name":"Clay Minerals","volume":"57 1","pages":"160 - 171"},"PeriodicalIF":1.5,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45135077","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ran Yuan, Wen-Ming Wang, Yi He, Yong Fang, Xi-Long Huang
Abstract This paper presents systematic molecular dynamics modelling of Na-montmorillonite subjected to uniaxial compression and unidirectional shearing. An initial 3D model of a single-cell Na-montmorillonite structure is established using the Build Crystal module. The space group is C2/m, and COMPASS force fields are applied. Hydration analysis of Na-montmorillonite has been performed to validate the simulation procedures, where the number of absorbed water molecules varied with respect to the various lattice parameters. A series of uniaxial compression stress σzz and unidirectional shear stress τxy values are applied to the Na-montmorillonite structure. It is shown that the lattice parameter and hydration degree exhibit significant influence on the stress–strain relationship of Na-montmorillonite. The ultimate strain increases with increases in the lattice parameter but decreases in the number of water molecules. For saturated Na-montmorillonite, more water molecules result in a stiffer clay mineral under uniaxial compression and unidirectional shearing.
{"title":"Molecular dynamics modelling of Na-montmorillonite subjected to uniaxial compression and unidirectional shearing","authors":"Ran Yuan, Wen-Ming Wang, Yi He, Yong Fang, Xi-Long Huang","doi":"10.1180/clm.2022.42","DOIUrl":"https://doi.org/10.1180/clm.2022.42","url":null,"abstract":"Abstract This paper presents systematic molecular dynamics modelling of Na-montmorillonite subjected to uniaxial compression and unidirectional shearing. An initial 3D model of a single-cell Na-montmorillonite structure is established using the Build Crystal module. The space group is C2/m, and COMPASS force fields are applied. Hydration analysis of Na-montmorillonite has been performed to validate the simulation procedures, where the number of absorbed water molecules varied with respect to the various lattice parameters. A series of uniaxial compression stress σzz and unidirectional shear stress τxy values are applied to the Na-montmorillonite structure. It is shown that the lattice parameter and hydration degree exhibit significant influence on the stress–strain relationship of Na-montmorillonite. The ultimate strain increases with increases in the lattice parameter but decreases in the number of water molecules. For saturated Na-montmorillonite, more water molecules result in a stiffer clay mineral under uniaxial compression and unidirectional shearing.","PeriodicalId":10311,"journal":{"name":"Clay Minerals","volume":"57 1","pages":"241 - 252"},"PeriodicalIF":1.5,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45829819","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Amraoui, S. Gamoudi, N. Baenas, M. Periago, E. Srasra
Abstract Clay minerals are used widely in health products both as cosmetic and pharmaceutical ingredients. To optimize use, natural compounds are mixed with clay powder. The aim of the present study was to synthesize new, coloured hybrids based on purified Tunisian clay and powders of natural flowers: Malva sylvestris, Chrysanthemum coronarium, Silene dioica, Anagallis monellin and Pelargonium × hortorum. The floral pigments in Tunisian flowers were studied. The chlorophylls (a and b), total flavonoids (TF), total phenolic compounds (TPC), and carotenoids were analyzed using UV-Vis spectrophotometry and high-performance liquid chromatography (HPLC-DAD). In addition, the antioxidant capacity was determined using the oxygenated radical absorption capacity assay (ORAC) and the antioxidant capacity to reduce ferric ion assay (FRAP). The properties of the studied clay were evaluated by means of pharmaceutical and microbiological tests. The coloured hybrids were prepared by solid–solid reaction and analyzed using X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. Chlorophyll a is present in large quantities in the Malva flower which presents the smallest antioxidant capacity. Chlorophyll b and the TPC are more abundant in the Pelargonium × hortorum. The TF appears in large quantities in the Anagallis flower. The carotenoids are present in the largest amounts in the Chrysanthemum. The results of the clay characterization justify its use as a pharmaceutical and cosmetic agent. The mixture of dried flowers and purified clay is used in the synthesis of new and biocoloured hybrids; these can be used as biocosmetic products without negative side effects on human health or the environment.
摘要粘土矿物作为化妆品和医药原料在保健品中有着广泛的应用。为了优化使用，天然化合物与粘土粉混合。本研究的目的是基于纯化的突尼斯粘土和天然花卉粉末合成新的彩色杂交品种:Malva sylvestris, Chrysanthemum coronarium, Silene dioica, Anagallis monellin和Pelargonium x hortorum。对突尼斯花的花色素进行了研究。采用紫外可见分光光度法和高效液相色谱法(HPLC-DAD)对其叶绿素(a、b)、总黄酮(TF)、总酚类化合物(TPC)和类胡萝卜素进行分析。此外，采用氧化自由基吸收能力(ORAC)和抗氧化还原铁离子能力(FRAP)测定了其抗氧化能力。通过药理学和微生物学试验对所研究的粘土的性能进行了评价。采用固固反应法制备了有色杂化物，并用x射线衍射(XRD)和傅里叶变换红外光谱(FTIR)对其进行了分析。叶绿素a大量存在于具有最小抗氧化能力的Malva花中。叶绿素b和TPC在天竺葵中含量较高。TF大量出现在穿山甲花中。类胡萝卜素在菊花中含量最高。粘土表征的结果证明了其作为制药和化妆品剂的用途。干花和纯化粘土的混合物用于合成新的和生物彩色杂交种;这些可以作为生物化妆品使用，对人体健康或环境没有负面副作用。
{"title":"Eco-friendly hybrid materials made from Tunisian clay and natural flowers","authors":"A. Amraoui, S. Gamoudi, N. Baenas, M. Periago, E. Srasra","doi":"10.1180/clm.2022.31","DOIUrl":"https://doi.org/10.1180/clm.2022.31","url":null,"abstract":"Abstract Clay minerals are used widely in health products both as cosmetic and pharmaceutical ingredients. To optimize use, natural compounds are mixed with clay powder. The aim of the present study was to synthesize new, coloured hybrids based on purified Tunisian clay and powders of natural flowers: Malva sylvestris, Chrysanthemum coronarium, Silene dioica, Anagallis monellin and Pelargonium × hortorum. The floral pigments in Tunisian flowers were studied. The chlorophylls (a and b), total flavonoids (TF), total phenolic compounds (TPC), and carotenoids were analyzed using UV-Vis spectrophotometry and high-performance liquid chromatography (HPLC-DAD). In addition, the antioxidant capacity was determined using the oxygenated radical absorption capacity assay (ORAC) and the antioxidant capacity to reduce ferric ion assay (FRAP). The properties of the studied clay were evaluated by means of pharmaceutical and microbiological tests. The coloured hybrids were prepared by solid–solid reaction and analyzed using X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. Chlorophyll a is present in large quantities in the Malva flower which presents the smallest antioxidant capacity. Chlorophyll b and the TPC are more abundant in the Pelargonium × hortorum. The TF appears in large quantities in the Anagallis flower. The carotenoids are present in the largest amounts in the Chrysanthemum. The results of the clay characterization justify its use as a pharmaceutical and cosmetic agent. The mixture of dried flowers and purified clay is used in the synthesis of new and biocoloured hybrids; these can be used as biocosmetic products without negative side effects on human health or the environment.","PeriodicalId":10311,"journal":{"name":"Clay Minerals","volume":"57 1","pages":"150 - 159"},"PeriodicalIF":1.5,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47953793","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zacharenia Kypritidou, M. Gatou, A. Argyraki, Vasilios Zotiadis
Abstract Clays have been used widely as sorbents of potentially toxic elements, especially Pb. However, their adsorption efficiency has been studied mostly under static experimental conditions, which are labour-intensive. In this study, dynamic adsorption experiments were established using micro-columns to assess the adsorption behaviour of natural Fe-Mg-rich clays for Pb ions by varying the inlet solution pH, Pb concentration and flow rate. The clays, consisting of varying amounts of palygorskite and Fe-smectite, were diluted with quartz (Qz) sand to enhance their permeability. Greater adsorption capacity was observed for the mixed palygorskite/Fe-smectite-rich clay beds (45.2 ± 0.01 mg g–1) followed by the Fe-smectite-rich (35.7 ± 0.07 mg g–1) and palygorskite-rich (20.0 ± 0.03 mg g–1) clay beds. The results indicated that the greater adsorption efficiency of palygorskite/Fe-smectite-rich clays could be attributed to synergistic effects due to the coexistence of palygorskite and Fe-smectite clay phases, which have distinct physicochemical characteristics. Moreover, the results obtained showed good agreement with the static experiments, implying that the use of micro-columns could describe adsorption adequately over shorter experimental times.
摘要粘土已被广泛用作潜在有毒元素的吸附剂，尤其是铅。然而，它们的吸附效率大多是在劳动密集型的静态实验条件下研究的。在本研究中，使用微柱建立了动态吸附实验，通过改变入口溶液pH、Pb浓度和流速来评估天然富铁镁粘土对Pb离子的吸附行为。粘土由不同数量的坡缕石和铁蒙脱石组成，用石英（Qz）砂稀释以提高其渗透性。观察到富含凹凸棒石/铁-蒙脱石的混合粘土床具有更大的吸附能力（45.2±0.01 mg g–1），其次是富含铁-蒙脱石（35.7±0.07 mg g–2）和富含凹凸棒岩（20.0±0.03 mg g g–1。结果表明，坡缕石/富铁蒙脱石粘土具有较高的吸附效率，这可能归因于坡缕石和富铁蒙脱石-粘土相共存的协同效应，它们具有明显的物理化学特征。此外，所获得的结果与静态实验显示出良好的一致性，这意味着使用微柱可以在更短的实验时间内充分描述吸附。
{"title":"Micro-column testing of the dynamic adsorption of Pb by Fe-Mg clay–quartz beds","authors":"Zacharenia Kypritidou, M. Gatou, A. Argyraki, Vasilios Zotiadis","doi":"10.1180/clm.2022.45","DOIUrl":"https://doi.org/10.1180/clm.2022.45","url":null,"abstract":"Abstract Clays have been used widely as sorbents of potentially toxic elements, especially Pb. However, their adsorption efficiency has been studied mostly under static experimental conditions, which are labour-intensive. In this study, dynamic adsorption experiments were established using micro-columns to assess the adsorption behaviour of natural Fe-Mg-rich clays for Pb ions by varying the inlet solution pH, Pb concentration and flow rate. The clays, consisting of varying amounts of palygorskite and Fe-smectite, were diluted with quartz (Qz) sand to enhance their permeability. Greater adsorption capacity was observed for the mixed palygorskite/Fe-smectite-rich clay beds (45.2 ± 0.01 mg g–1) followed by the Fe-smectite-rich (35.7 ± 0.07 mg g–1) and palygorskite-rich (20.0 ± 0.03 mg g–1) clay beds. The results indicated that the greater adsorption efficiency of palygorskite/Fe-smectite-rich clays could be attributed to synergistic effects due to the coexistence of palygorskite and Fe-smectite clay phases, which have distinct physicochemical characteristics. Moreover, the results obtained showed good agreement with the static experiments, implying that the use of micro-columns could describe adsorption adequately over shorter experimental times.","PeriodicalId":10311,"journal":{"name":"Clay Minerals","volume":"57 1","pages":"253 - 263"},"PeriodicalIF":1.5,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46935734","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mouhssin El Halim, L. Daoudi, M. El Ouahabi, N. Fagel
Abstract Clays from the Saïss basin (northern Morocco) used traditionally in the ceramic industry in the Fez area were studied using mineralogical and physicochemical techniques to evaluate their potential suitability as raw materials for ceramics manufacture. X-ray diffraction was used to determine their mineralogical composition. The physical properties determined were particle-size distribution and consistency limits. The chemical composition was determined using X-ray fluorescence analysis and Fourier-transform infrared spectrometry. The structural changes of the mineral phases in the raw materials during firing were studied over a temperature range of 500–1000°C. In the pottery site from Fez, generally potters use a mixture of 25% fine clay (ARFS) from the upper part of the Miocene marls and 75% sandy clay (ARFR) from the lower part of the Miocene marls. The ARFS clay yielded very rigid specimens after firing that artisan potters would find difficult to handle so as to produce desired shapes and sizes. However, the specimens obtained from ARFR clay show signs of faltering. The mixture of these two clayey materials from this pottery site is therefore necessary to obtain the optimal paste for ceramics purposes. The chemical compositions indicated that SiO2, Al2O3, CaO and Fe2O3 are the major minerals, with trace amounts of K2O and MgO. Quartz, feldspars and clay minerals prevail in all samples. Kaolinite, illite and smectite are the dominant clay mineral phases, with traces of chlorite and interstratified illite–smectite. The classification of these samples using appropriate ternary diagrams showed that the proportions used in the mixture produce a new material with adequate characteristics for the production of traditional ceramics.
{"title":"Characterization of clays from the Fez area (northern Morocco) for potential uses in the ceramics industry","authors":"Mouhssin El Halim, L. Daoudi, M. El Ouahabi, N. Fagel","doi":"10.1180/clm.2022.30","DOIUrl":"https://doi.org/10.1180/clm.2022.30","url":null,"abstract":"Abstract Clays from the Saïss basin (northern Morocco) used traditionally in the ceramic industry in the Fez area were studied using mineralogical and physicochemical techniques to evaluate their potential suitability as raw materials for ceramics manufacture. X-ray diffraction was used to determine their mineralogical composition. The physical properties determined were particle-size distribution and consistency limits. The chemical composition was determined using X-ray fluorescence analysis and Fourier-transform infrared spectrometry. The structural changes of the mineral phases in the raw materials during firing were studied over a temperature range of 500–1000°C. In the pottery site from Fez, generally potters use a mixture of 25% fine clay (ARFS) from the upper part of the Miocene marls and 75% sandy clay (ARFR) from the lower part of the Miocene marls. The ARFS clay yielded very rigid specimens after firing that artisan potters would find difficult to handle so as to produce desired shapes and sizes. However, the specimens obtained from ARFR clay show signs of faltering. The mixture of these two clayey materials from this pottery site is therefore necessary to obtain the optimal paste for ceramics purposes. The chemical compositions indicated that SiO2, Al2O3, CaO and Fe2O3 are the major minerals, with trace amounts of K2O and MgO. Quartz, feldspars and clay minerals prevail in all samples. Kaolinite, illite and smectite are the dominant clay mineral phases, with traces of chlorite and interstratified illite–smectite. The classification of these samples using appropriate ternary diagrams showed that the proportions used in the mixture produce a new material with adequate characteristics for the production of traditional ceramics.","PeriodicalId":10311,"journal":{"name":"Clay Minerals","volume":"57 1","pages":"139 - 149"},"PeriodicalIF":1.5,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45559957","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract The rare earth element (REE) content of the Tunisian Permian–Neogene shales have been studied to determine the origins of the clay minerals in these shales. The Permian–Neogene series overlies the Palaeozoic basement that has been studied via oil-drilling cores. This study of REEs was performed in various palaeogeographical domains of Tunisia, from the ‘Saharan Platform’ in the south to the ‘Nappes Zone’ in the north. In this work, those levels rich in illite (Palaeozoic, Triassic and Jurassic), smectite (Campanian–Maastrichtian) and palygorskite (continental Eocene) as well as some Miocene levels rich in halloysite are examined. The distribution of REEs in the Tunisian margin sediments is generally homogeneous, except for the Miocene levels containing halloysites. The normalization curves of REEs vs North American shale composite characterize the inherited clays regardless of the dominant minerals, except for a few cases of neoformation. The flat REE curves indicate a detrital origin of the studied clay levels.
{"title":"Distribution of rare earth elements of Tunisian margin clays","authors":"F. Jamoussi, A. López Galindo","doi":"10.1180/clm.2023.1","DOIUrl":"https://doi.org/10.1180/clm.2023.1","url":null,"abstract":"Abstract The rare earth element (REE) content of the Tunisian Permian–Neogene shales have been studied to determine the origins of the clay minerals in these shales. The Permian–Neogene series overlies the Palaeozoic basement that has been studied via oil-drilling cores. This study of REEs was performed in various palaeogeographical domains of Tunisia, from the ‘Saharan Platform’ in the south to the ‘Nappes Zone’ in the north. In this work, those levels rich in illite (Palaeozoic, Triassic and Jurassic), smectite (Campanian–Maastrichtian) and palygorskite (continental Eocene) as well as some Miocene levels rich in halloysite are examined. The distribution of REEs in the Tunisian margin sediments is generally homogeneous, except for the Miocene levels containing halloysites. The normalization curves of REEs vs North American shale composite characterize the inherited clays regardless of the dominant minerals, except for a few cases of neoformation. The flat REE curves indicate a detrital origin of the studied clay levels.","PeriodicalId":10311,"journal":{"name":"Clay Minerals","volume":"57 1","pages":"285 - 296"},"PeriodicalIF":1.5,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46086917","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Pelayo, T. Schmid, F. J. Díaz-Puente, J. López-Martínez
Abstract The environmental conditions in Maritime Antarctica are more favorable to soil development than in continental areas, which is reflected in the content and type of clay minerals present. In this context, soil clay minerals of Fildes Peninsula, South Shetland Islands were studied with the aim of relating them to periglacial and paraglacial processes as possible indicators of initial pedogenic processes. In this work, textural, mineralogical and crystallochemical characterization of clay minerals as well as chemical and physical soil analyses were carried out. The soil samples represented various surface cover types present on Fildes Peninsula. All samples were composed mainly of clay minerals, plagioclase, quartz and minor zeolites and pyroxene. The clay mineral content was very variable and reached up to 63% w/w. The clay minerals present are mainly smectite, vermiculite, chlorite and minor kaolinite, mica, corrensite and interstratified illite–smectite, with smectite and vermiculite dominating in almost all of the samples. The primary minerals display chemical alteration, and smectite formed by alteration of plagioclase. The clay mineral types were related to the parent material, which was affected by low-grade metamorphism and hydrothermal alteration that transformed biotite and chlorite into vermiculite via interstratified chlorite–vermiculite. Furthermore, this process and/or ongoing surface weathering transformed vermiculite into smectite. The genetic relationship observed between vermiculite and smectite suggests progressive alteration and transformation into a phase with intermediate composition between vermiculite and smectite. Therefore, vermiculite could be at least in part the smectite precursor. Samples closer to the current Collins Glacier front are composed mainly of vermiculite, with the greatest chemical variation occurring where the soils were developed from a mixture of initially glacially transported volcanic rocks through periglacial and fluvial processes. The clay minerals from the centre and south of Fildes Peninsula are mixtures of montmorillonite and vermiculite, as well as of chlorite and corrensite in various proportions. The clay minerals in soils developed on the west coast are a mixture of Fe-rich montmorillonite and vermiculite.
{"title":"Characterization and distribution of clay minerals in the soils of Fildes Peninsula and Ardley Island (King George Island, Maritime Antarctica)","authors":"M. Pelayo, T. Schmid, F. J. Díaz-Puente, J. López-Martínez","doi":"10.1180/clm.2022.46","DOIUrl":"https://doi.org/10.1180/clm.2022.46","url":null,"abstract":"Abstract The environmental conditions in Maritime Antarctica are more favorable to soil development than in continental areas, which is reflected in the content and type of clay minerals present. In this context, soil clay minerals of Fildes Peninsula, South Shetland Islands were studied with the aim of relating them to periglacial and paraglacial processes as possible indicators of initial pedogenic processes. In this work, textural, mineralogical and crystallochemical characterization of clay minerals as well as chemical and physical soil analyses were carried out. The soil samples represented various surface cover types present on Fildes Peninsula. All samples were composed mainly of clay minerals, plagioclase, quartz and minor zeolites and pyroxene. The clay mineral content was very variable and reached up to 63% w/w. The clay minerals present are mainly smectite, vermiculite, chlorite and minor kaolinite, mica, corrensite and interstratified illite–smectite, with smectite and vermiculite dominating in almost all of the samples. The primary minerals display chemical alteration, and smectite formed by alteration of plagioclase. The clay mineral types were related to the parent material, which was affected by low-grade metamorphism and hydrothermal alteration that transformed biotite and chlorite into vermiculite via interstratified chlorite–vermiculite. Furthermore, this process and/or ongoing surface weathering transformed vermiculite into smectite. The genetic relationship observed between vermiculite and smectite suggests progressive alteration and transformation into a phase with intermediate composition between vermiculite and smectite. Therefore, vermiculite could be at least in part the smectite precursor. Samples closer to the current Collins Glacier front are composed mainly of vermiculite, with the greatest chemical variation occurring where the soils were developed from a mixture of initially glacially transported volcanic rocks through periglacial and fluvial processes. The clay minerals from the centre and south of Fildes Peninsula are mixtures of montmorillonite and vermiculite, as well as of chlorite and corrensite in various proportions. The clay minerals in soils developed on the west coast are a mixture of Fe-rich montmorillonite and vermiculite.","PeriodicalId":10311,"journal":{"name":"Clay Minerals","volume":"57 1","pages":"264 - 284"},"PeriodicalIF":1.5,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44383569","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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