共查询到19条相似文献,搜索用时 140 毫秒
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1989年初,贵州省地矿局区域地质调查大队曾将大方县二叠系龙潭组合黄铁矿粘土岩定名为累土石粘土岩,尔后省地矿局地质实验研究所和113队亦将其定名为累托石。我们经过研究,认为主要粘土矿物应是伊/蒙不规则间层矿物。 1.X射线衍射特征:粘上岩分离重矿物后的粘土部分X射线结果表明,所有样品的d值1.0~1.5nm范围内均有一个明显的峰值,这是伊/蒙间层矿物特征标志。在0~5℃范围内, 相似文献
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金云母—蛭石间层矿物分晶层晶体化学式的计算及意义 总被引:10,自引:0,他引:10
金云母-蛭石间层矿物由金云母晶层与蛭石晶层交叠排列而成,采用一般计算方法得出的晶体化学式不能充分揭示结构中金云母晶层与蛭石晶层各自的晶体化学特征。本文以化学成分分析与阳离子容量为基础,假定可交换性阳离子均为蛭石晶层层间阳离子,非交换性阳离子为金云母晶层层间阳离子,金云母晶层与蛭石晶层具有相同的八面体层等,计算出了结构中两种晶层的分晶层晶体化学式,确定了结构中两种晶层的比例和蛭石晶层的电荷数。并在此基础上讨论了新疆尉犁蛭石矿金云母-蛭石间层矿物的晶体化学特征。结果表明该方法设计合理,符合晶体化学原理,所计算的数据可靠。利用该方法计算出的两种晶层的比例为金云母-蛭石1:1规则间层矿物的确定提供了必要的依据。也为其它类似间层矿物的研究提供了一种计算分晶层晶体化学式的可行方法。 相似文献
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关于我国南方P/T界线粘土中I/S混层矿物类型的商榷 总被引:2,自引:0,他引:2
本文依据目前世界上较流行的I/S混层矿物有序类型划分及鉴定方法,对已公布的我国南方P/T界线粘土岩中I/S混层矿物的有序类型进行重新讨论.结果发现,这些混层矿物实则为IS或ISII有序间层,而非原作者所认定的不规则混层,温层比也明显不同。 相似文献
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朱立军 《矿物岩石地球化学通报》1996,(3)
碳酸盐岩红土中1.4nm间层矿物及其环境意义朱立军(贵州工学院,贵阳550003)关键词红土,间层矿物,土壤环境1.4nm间层矿物是指由绿泥石晶层与2:1型含水膨胀层交互连生所构成的不规划间层粘土矿物,其中2:1型含水晶层可以是蒙脱石层,也可以是蛭石... 相似文献
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华北石炭二叠纪煤系中I/S间层矿物的研究 总被引:1,自引:1,他引:1
华北石炭二叠煤系中的I/S间层粘土岩夹矸或粘土岩层,在太行山以东较为发育。I/S间层矿物的类型有累托石、IS有序间层矿物、S/I无序间层矿物,它们是在近岸泥岩沼泽或沼泽环境中由同期降落的火山灰蚀变而成,在酸性介质的影响下,形成IS有序间层矿物,在偏碱性的介质条件下,形成S/I无序间层矿物;高压异常区则形成累托石。 相似文献
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层状硅酸盐矿物晶体结构的多体性组装模式与构筑原理 总被引:2,自引:0,他引:2
将层状硅酸盐矿物晶体结构中属性不同的二维结构单元体看成是不同的结晶学模块,研究了一般层状硅酸盐矿物和间层矿物的多体性组装模式和构筑原理。结果表明,不同二维结构单元体(包括硅氧四面体片、八面体片、层间域(物))的构筑基本符合球体紧密堆积原理,紧密堆积层平行{0001};四面体片与八面体片构筑TO和TOT结构层时采取多种机制消除二者在二维尺寸上的差异;两种模式的结构层与不同类型的层间物(域)组装形成六种组装模式的晶层;并通过二维结构单元体的组合规律的分析,计算出可能存在的28种TOT型间层结构,它们分属于6种间层结构多体性组装模式;间层结构中,结构层对于八面体片是不对称的,并在属性上表现出极性特征;间层矿物的晶层类型可用6种多体性组装模式加以表达。层状硅酸盐矿物结构的多体性分析与组装模式的研究,对于矿物晶体化学研究是非常重要的。 相似文献
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Abstract Five basalt samples from the Point Sal ophiolite, California, were examined using HRTEM and AEM in order to compare observations with interpretations of XRD patterns and microprobe analyses. XRD data from ethylene-glycol-saturated samples indicate the following percentages of chlorite in mixed-layer chlorite–smectite identified for each specimen: (i) L2036 ± 50%, (ii) L2035 ± 70 and 20%, (iii) 1A-13 ± 70%, (iv) 1B-42 ± 70%, and (v) 1B-55 = 100%. Detailed electron microprobe analyses show that 'chlorite'analyses with high Si, K, Na and Ca contents are the result of interlayering with smectite-like layers. The Fe/(Fe + Mg) ratios of mixed-layer phyllosilicates from Point Sal samples are influenced by the bulk rock composition, not by the percentage of chlorite nor the structure of the phyllosilicate.
Measurements of lattice-fringe images indicate that both smectite and chlorite layers are present in the Point Sal samples in abundances similar to those predicted with XRD techniques and that regular alternation of chlorite and smectite occurs at the unit-cell scale. Both 10- and 14-Å layers were recorded with HRTEM and interpreted to be smectite and chlorite, respectively. Regular alternation of chlorite and smectite (24-Å periodicity) occurs in upper lava samples L2036 and 1A-13, and lower lava sample 1B-42 for as many as seven alternations per crystallite with local layer mistakes. Sample L2035 shows disordered alternation of chlorite and smectite, with juxtaposition of smectite-like layers, suggesting that randomly interlayered chlorite (<0.5)–smectite exists. Images of lower lava sample 1B-55 show predominantly 14-Å layers. Units of 24 Å tend to cluster in what may otherwise appear to be disordered mixtures, suggesting the existence of a corrensite end-member having thermodynamic significance. 相似文献
Measurements of lattice-fringe images indicate that both smectite and chlorite layers are present in the Point Sal samples in abundances similar to those predicted with XRD techniques and that regular alternation of chlorite and smectite occurs at the unit-cell scale. Both 10- and 14-Å layers were recorded with HRTEM and interpreted to be smectite and chlorite, respectively. Regular alternation of chlorite and smectite (24-Å periodicity) occurs in upper lava samples L2036 and 1A-13, and lower lava sample 1B-42 for as many as seven alternations per crystallite with local layer mistakes. Sample L2035 shows disordered alternation of chlorite and smectite, with juxtaposition of smectite-like layers, suggesting that randomly interlayered chlorite (<0.5)–smectite exists. Images of lower lava sample 1B-55 show predominantly 14-Å layers. Units of 24 Å tend to cluster in what may otherwise appear to be disordered mixtures, suggesting the existence of a corrensite end-member having thermodynamic significance. 相似文献
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《矿物学报》2013,(Z1)
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. 相似文献
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AFSOON M. KAZEROUNI METTE L. K. POULSEN HENRIK FRIIS JOHAN B. SVENDSEN JENS P. V. HANSEN 《Sedimentology》2013,60(3):679-692
Detrital glaucony in the Palaeogene glauconitic sandstones in Siri Canyon, Danish North Sea, has been analysed from 15 exploration wells by X‐ray diffraction, electron microprobe and scanning electron microscopy. These sandstones consist of mixed‐layer illite/smectite and have a large variability in chemical composition and structure. In the most shallow wells (ca 1700 m), the glaucony is rich in Fe and consists of mixed‐layer illite/smectite with random‐interstratification (R = 0). In the depth interval from 1700 to 2000 m, the composition changes as Si is incorporated. The structure changes to ordered R = 1. Further increase in burial leads to the loss of Fe. Ordered R = 3 mixed‐layer illite/smectite is recognized from burial depths of 2200 m. The proportion of illite in illite/smectite mixed layers increases only slightly with depth and temperature. Although the structural changes generally are associated with chemical changes, they can also take place isochemically when the detrital glaucony is tightly embedded in earlier cement, which prevented chemical exchange. The glaucony transformation in the Siri Canyon sandstones partly reflects a supply of Si and partly significant loss of Fe. Thus, the glaucony transformation relates to the general diagenesis of the host sandstone. These sandstones are cemented by microquartz at an early stage, followed by precipitation of Fe‐rich grain‐coating berthierine or chlorite. 相似文献
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为了解天津蓟县长城系串岭沟组地层中混层粘土矿物的组成和结构特征, 利用X射线粉晶衍射(XRD) 和高分辨透射电镜(HRTEM) 对其进行了深入研究.通过对比该区粘土矿物的自然干燥片、Ca离子饱和片、Ca饱和的乙二醇膨胀片、加热到375℃和550℃的乙二醇膨胀片获取的XRD衍射峰, 确定该区混层粘土矿物为伊利石/蒙脱石(I/S) 不规则混层矿物和绿泥石/蒙脱石(Chl/S) 不规则混层矿物.从高分辨透射电镜观察到I/S规则及不规则混层的晶格条纹像以及Chl/S不规则混层的晶格条纹像, 揭示了该区I/S混层和Chl/S混层的层间堆跺结构特征.该研究为蓟县中元古界典型剖面提供了重要的混层粘土矿物的结构信息. 相似文献
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Naturally weathered feldspar surfaces in the Navajo Sandstone aquifer, Black Mesa, Arizona: Electron microscopic characterization 总被引:1,自引:0,他引:1
Naturally weathered feldspar surfaces in the Jurassic Navajo Sandstone at Black Mesa, Arizona, was characterized with high-resolution transmission and analytical electron microscope (HRTEM-AEM) and field emission gun scanning electron microscope (FEG-SEM). Here, we report the first HRTEM observation of a 10-nm thick amorphous layer on naturally weathered K-feldspar in currently slightly alkaline groundwater. The amorphous layer is probably deficient in K and enriched in Si. In addition to the amorphous layer, the feldspar surfaces are also partially coated with tightly adhered kaolin platelets. Outside of the kaolin coatings, feldspar grains are covered with a continuous 3-5 μm thick layer of authigenic smectite, which also coats quartz and other sediment grains. Authigenic K-feldspar overgrowth and etch pits were also found on feldspar grains. These characteristics of the aged feldspar surfaces accentuate the differences in reactivity between the freshly ground feldspar powders used in laboratory experiments and feldspar grains in natural systems, and may partially contribute to the commonly observed apparent laboratory-field dissolution rate discrepancy. At Black Mesa, feldspars in the Navajo Sandstone are dissolving at ∼105 times slower than laboratory rate at comparable temperature and pH under far from equilibrium condition. The tightly adhered kaolin platelets reduce the feldspar reactive surface area, and the authigenic K-feldspar overgrowth reduces the feldspar reactivity. However, the continuous smectite coating layer does not appear to constitute a diffusion barrier. The exact role of the amorphous layer on feldspar dissolution kinetics depends on the origin of the layer (leached layer versus re-precipitated silica), which is uncertain at present. However, the nanometer thin layer can be detected only with HRTEM, and thus our study raises the possibility of its wide occurrence in geological systems. Rate laws and proposed mechanisms should consider the possibility of this amorphous layer on feldspar surface. 相似文献
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对珠江口盆地两口钻井95个泥质岩样粘土矿物X衍射分析资料的定量研究表明,若反应是以消耗蒙皂石为代价形成伊利石,则反应符合溶解-沉淀机理,但除此以外,蒙皂石还可以净溶解或新增伊利石层的方式加大I/S比。蒙皂石在渐进成岩过程中的框架性行为模式具有三级控制,按顺序分别由温度、基本离子成分和动力学因素控制特定温度段内蒙皂石行为过程的起始和终结、行为过程的方式和行为过程的速率和程度。渐进成岩过程中I/S比的变化主要与第三级控制有关,而游离状蒙皂石和伊-蒙混层粘土的含量变化则是第二三两级共同控制的结果。 相似文献
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Youko Miyoshi Jun‐ichiro Ishibashi Kazuhiko Shimada Hiroyasu Inoue Seiichiro Uehara Katsuhiro Tsukimura 《Resource Geology》2015,65(4):346-360
Iheya‐North‐Knoll is one of the small knolls covered with thick sediments in the Okinawa Trough back‐arc basin. At the east slope of Iheya‐North‐Knoll, nine hydrothermal vents with sulfide mounds are present. The Integrated Ocean Drilling Program (IODP) Expedition 331 studied Iheya‐North‐Knoll in September 2010. The expedition provided us with the opportunity to study clay minerals in deep sediments in Iheya‐North‐Knoll. To reveal characteristics of clay minerals in the deep sediments, samples from the drilling cores at three sites close to the most active hydrothermal vent were analyzed by X‐ray diffraction, scanning electron microscope and transmission electron microscope. The sediments are classified into Layer 0 (shallow), Layer 1 (deep), Layer 2 (deeper) and Layer 3 (deepest) on the basis of the assemblage of clay minerals. Layer 0 contains no clay minerals. Layer 1 contains smectite, kaolinite and illite/smectite mixed‐layer mineral. Layer 2 contains chlorite, corrensite and chlorite/smectite mixed‐layer mineral. Layer 3 is grouped into three sub‐layers, 3A, 3B and 3C; Sub‐layer 3A contains chlorite and illite/smectite mixed‐layer mineral, sub‐layer 3B contains chlorite/smectite and illite/smectite mixed‐layer minerals, and sub‐layer 3C contains chlorite and illite. Large amounts of di‐octahedral clay minerals such as smectite, kaolinite, illite and illite/smectite mixed‐layer mineral are found in Iheya‐North‐Knoll, which is rarely observed in hydrothermal fields in mid‐ocean ridges. Tri‐octahedral clay minerals such as chlorite, corrensite and chlorite/smectite mixed‐layer mineral in Iheya‐North‐Knoll have low Fe/(Fe + Mg) ratios compared with those in mid‐ocean ridges. In conclusion, the characteristics of clay minerals in Iheya‐North‐Knoll differ from those in mid‐ocean ridges; di‐octahedral clay minerals and Fe‐poor tri‐octahedral clay minerals occur in Iheya‐North‐Knoll but not in mid‐ocean ridges. 相似文献
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松辽盆地扶新隆起带北部扶余油层超低渗储层
粘土矿物特征及其对敏感性的影响 总被引:4,自引:0,他引:4
以储层敏感性流动实验为基础,结合X射线衍射、扫描电镜、铸体薄片等方法,对松辽盆地扶新隆起带北部扶余油层超低渗储层粘土矿物特征及其对储层敏感性的影响进行了研究,结果表明:扶余油层主要含有绿泥石、伊利石、高岭石和伊/蒙混层等4种矿物,其中伊利石含量最多,绿泥石和伊/蒙混层次之,高岭石最少。储层速敏性和碱敏性相对较弱,水敏性和盐敏性较强,对储层影响较大,勘探开发时应重点关注。粘土矿物对储层水敏性的影响主要有3个方面,其中粘土矿物绝对总量是扶余油层水敏性强弱的主控因素。 相似文献