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The x-ray identification and crystal structures of clay minerals

01 Jan 1961-
About: The article was published on 1961-01-01 and is currently open access. It has received 966 citations till now. The article focuses on the topics: Clay minerals.
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Journal ArticleDOI
TL;DR: The great reduction of DOC from LF and AL with aging has been shown to affect adsorption of metalaxyl and tricyclazole, and this effect is dependent on the pesticide, the nature of the DOC, and the type of soil, in particular its clay mineralogy.
Abstract: The effect of aging in the soil of three organic amendments (OAs), one liquid (LF) and two solid ones (SF and AL), has been investigated and related to changes in soil adsorption of metalaxyl and tricyclazole. LF and AL have very high dissolved organic carbon (DOC) contents with low humification index values, whereas SF has a low DOC content but the highest amounts of highly humified material. All OAs increased the adsorption of tricyclazole, whereas adsorption of metalaxyl decreased in soils amended with LF and AL, due to competition with DOC for mineral adsorption sites. With aging, DOC from SF amended soils is not significantly affected and neither is adsorption behavior. On the contrary, the great reduction of DOC from LF and AL with aging has been shown to affect adsorption of metalaxyl and tricyclazole, and this effect is dependent on the pesticide, the nature of the DOC, and the type of soil, in particular its clay mineralogy.

55 citations

Journal ArticleDOI
TL;DR: The lattice structure of a synthetic ammonium dioctahedral clay (designated SMM) is shown to lie similar to muscovite mica as mentioned in this paper, where SMM has irregularly interstratified expandable and nonexpandable layers before activation.

55 citations

Journal ArticleDOI
TL;DR: In this article, the isotope data suggest that the eventual formation of chlorite during deep burial occurred from waters with positive δ 18 O values, comparable to those present during the deep burial formation of illite, suggesting that formation of a precursor was related to lateral migration of Mg-rich fluids from basinal shales and/or evaporites during shallow burial.
Abstract: Pore-lining chlorite is common in Rotliegend lake shoreline aeolian sandstones from northern Germany and preserves abnormally high primary intergranular porosity. In the north of the study area, in a basinward direction, the chlorites are Mg-rich while towards the south they become Fe-rich over a distance of about 15 km. All are unusually rich in Mn. Magnesium-rich examples tend to be more abundant than illite, while Fe-rich examples cover framework grains less continuously and are admixed with more abundant illite. Oxygen isotope analysis of 30 chlorites in the 2-6 μm fraction gave δ 18 O (SMOW) values of 7 to 12‰ (mean 9.8‰). These data show no obvious trend across the study area, nor in relation to changes in chlorite composition, or burial depth. The honeycomb arrangement of chlorite crystals suggests chlorite formation via the sequence smectite-corrensite-chlorite. Chlorite distribution and the systematic changes in its composition suggest that formation of a precursor was related to lateral migration of Mg-rich fluids from basinal shales and/or evaporites during shallow burial. Interaction of these fluids with early formed oxy-hydroxide coatings on the aeolian sand grains provided a source of Fe and the Mn. The isotope data suggest that the eventual formation of chlorite during deep burial occurred from waters with positive δ 18 O values, comparable to those present during the deep burial formation of illite.

53 citations

Journal ArticleDOI
01 Jan 1999-Analyst
TL;DR: The usefulness of photoacoustic techniques in characterizing the thermal properties of kaolinite clays, which are a very abundant mineral in some regions of Brazil, was investigated in this article.
Abstract: The usefulness of photoacoustic techniques in characterizing the thermal properties of kaolinite clays, which are a very abundant mineral in some regions of Brazil, was investigated. Different behavioural patterns are observed below and above a heating temperature of 950 °C and can be attributed to the change from metakaolinite to an amorphous three-dimensional mineral which crystallises to mullite and crystobalite above 1200 °C. The implications of the results in the manufacture of clay bricks are briefly considered. This is important in tropical regions where a knowledge of the thermal properties of materials used in the building construction industry is highly desirable.

53 citations

Journal ArticleDOI
TL;DR: Glimmerartige Schichtsilicate wie Montmorillonit und Vermiculit konnen ihre Kationen gegen andere, auch organische Kationens zeolithisch austauschen as discussed by the authors.
Abstract: Glimmerartige Schichtsilicate wie Montmorillonit und Vermiculit konnen ihre Kationen gegen andere, auch organische Kationen zeolithisch austauschen. Diese Derivate quellen in vielen Flussigkeiten. Die Arbeit gibt einen Uberblick uber die Struktur und die technische Verwertbarkeit der organischen Derivate von glimmerartigen Schichtsilicaten.

53 citations