The specific layered silica hydrate and alumino-silica hydrate can be prepared from apophyllite has been reported. In this study, three samples were prepared from apopohyllite and examined their cation adsorption properties with methylene blue molecules as a probe. The samples were prepared in two ways; natural apophyllite was (1) treated with hydrochloric acid at 5°C and (2) treated with aluminum chloride solution at room temperature. Two alumino-silica samples were prepared by varying the concentration of the reaction solution. As a result, these alumino-silica samples had different Al/Si ratio from each other.
For the silica sample, it is found that the amount of adsorbed methylene blue molecules increased with increasing pH value of the solution. This tendency suggested that methylene blue adsorption was due to broken bond covalence of silica samples. In the case of the alumino-silica samples, amount of adsorbed methylene blue were seemed to be independent of pH value of the solution. This result indicated that negative charges of the almino-silica sheets did not change in these conditions. Therefore, it suggested that aluminum atoms forming the frameworks were mainly attributed to methylene blue adsorption. According to the X-ray diffraction patterns, methylene blue molecules could not be introduced between the slilca-sheets of the samples. Since the internal surfaces are not available to the adsorption ofmethylene blue, the amounts of adsorbed methylene blue molecules are much smaller than that of the other clay minerals.
UV spectra of methylene blue on all samples showed that some of methylene blue molecules formed dimer and trimer on the surfaces of the samples.

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Clayey bioremediation at Osorezan area in Shimokita Peninsula, Aomori Prefecture, is reported in this paper. The relations among river sediments, plants and bacteria to bioremediation under strong acidic condition were revealed by SEM-EDX observation and ED-XRF analyses. The clayey sediments contain a large amount of arsenic which is toxic for living things. But, algae, sickle-shaped bacteria, and Scirpus lacustris L. of vascular plant survive in this geothermal area. The algae grow in black microbial mats at pH 3.0, Eh 102 mV, and DO 8.7mg/l condition. The sickle-shaped bacteria are observed in hot spring water at 42°C. Scirpus lacustris L. of vascular plant predominantly was observed around a stream. They have been survived to obtain the ability of tolerance of toxic elements such as As, Ti and Fe. These microorganisms and lower plants of endurance against toxic elements could be useful to bioremediation at heavy metal contaminated sediments. Furthermore, sulfides and sulphur play an important role in retaining and remobilizing arsenic from contaminated sediments. Clays will scavenge the arsenic with the formation of Asmaterials.

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Microorganisms are influential in environmental earth materials. Elemental circulation, environmental changes and the Earth evolution have been associated with microorganisms. In this study, biomineralization of clay minerals and biodegradation of K-feldspar and biotite in granite were identified by XRD, optical microscope, SEM-EDX, TEM and atomic absorption.
Bioweathering experiments were carried out using thin section of granite in freshwater with iron bacteria (Toxothrix and Gallionella) at Omma Formation, Ishikawa Pref., Japan. Microbial mats were formed on the surface of the thin section after 3 and 10 days. Cavities and chaps with bacilli and filamentous bacteria were observed on the surface of feldspars and biotite. Si content was reduced at flake materials (Si:Al=3:2) with bacilli on the surface of K-feldspar. K and Si release was recognized in the solution of both K-feldspar and biotite immersed in the freshwater after a 2 months aging. TEM observation and electron diffraction analyses revealed that kaolinite formed on the surface of K-feldspar immersed in the freshwater after 2 months, suggesting K and Si were released from K-feldspar by bacteria to form kaolinite. The results suggest that the weathering of granite were accelerated by microorganisms to offer the nutrients such as K-ion.

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Liesegang ring has been well known as typical periodic precipitation pattern formed during diffusion process of chemical elements in gel and/or solution. Liesegang rings (several milimeters to a few centimeters in width) are characteristically developed in pyrophyllite ore deposits in Shobara district, Hiroshima prefecture, Southwest Japan. The mode of occurrence and mineralogical and chemical characteristics of the Liesegang ring were examined by means of optical microscope, X-ray diffraction, Xray fluorescence, electron microprobe and nuclide luminoscope. The Liesegang ring characterized by distinct alternate of deep and light color rings is developed in the extensively altered rocks which consist of pyrophyllite, sericite, interstratified mineral of mica and smectite, kaolinite, quartz and hematite. Hematite rings are characteristically observed in the both rings, particularly in deep color ring. Two types of rings are recognizable, one is perpendicular and the other is paralel to the flow structure of host rhyolitic rocks, respectively. The former is observed in close to pyrophyllite ore, the latter mainly in the marginal part of ore. These facts suggest that the formation mechanism of Liesegang rings relates intimately to the regional pyrophyllitic alteration of the district.

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Clay mineral assemblage reflects sedimentary environment such as difference of source materials, sedimentary temperature, and depth of deposition. Sequential clay mineralogical analyses of fossil free stratum give constraint on depositional environment of sedimentary rocks. The clay mineralogical analyses of the Kuruma Group, early Jurassic thick clastic sediments for stratum by stratum method made clear frequent transition of sedimentary environment. The clay mineral composition of the Kuruma Group is characterized by fluctuation of kaolinite ratio to smectite and mica clay minerals. Increase of kaolinite content suggests shallow and near-coast sedimentary environment influenced in freshwater. The presence of brackish molluscan fossils and fossilized trunk also supports near coast environment. Clay mineralogical analyses suggest that increase of smectite and mica clay minerals contents reflect off shore sedimentary environment. Marine molluscan such as ammonites, crinoids and brachiopods support this effect. The Kuruma Group is situated on the Hida marginal Terrane, characterized by Permian to Triassic accretion sediments of serpentinite mélange with the Hida semi-continental margin. Chemical compositions of this Group indicate that the source of clastic sediments of the Kuruma Group is acidic rocks rather than basic rocks composed of the Hida marginal Terrane. Dramatic change of kaolinite and smectite ratios of the Kuruma Group suggests global oceanic environmental change such as fluctuation of sea level due to subdivision of super-continent (Pangea). Decrease of kaolinite and increase of smectite suggest the rise of sea level. It is plausible that global oceanic event gave influence on the near coast sediments such as the Kuruma Group. The studies of sequence stratigraphy, isotopic data and paleontological research also support the presence of global oceanic events. The clay minerals have recorded the change of sedimentary system and the geological phenomena caused by various causes. Clay mineral analysis is possible to contribute to the studies on the paleo-environmental analysis, because the clay minerals are extremely sensitive to change of the environments. This study reports new paleo-environmental analysis of the early Jurassic Kuruma Group based on the analyses of clay mineral composition and the chemical composition of the sedimentary rocks related with the change of paleontological faces and global oceanic events.

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Vermiculitization process of biotite from a weathering profile of the Cretaceous Shinshiro tonalite was examined by means of X-ray diffraction, exchangeable inter-layer cation analysis and electron microprobe analysis. Biotite from the fresh rock shows a sharp 10Å basal reflection, but its Na-and Ca-modifications give distinct two basal reflections: 10 and 12.5Å for Na-modification and 10 and 15.3Å for Ca-modification. The exchangeable inter-layer cations, dominantly K and Mg, amount to 15.3meq/100g. The biotite from the fresh rock, in fact, contains microdomains of K·Mg-vermiculite. The basal refrections of the Na-and Ca-modifications broaden as the weathering increases. The exchangeable inter-layer cations are dominated by Ca in most weathered biotite, but the amount remains unchanged (15.0-19.0meq/100g) through the samples. The K·Mg-vermiculite formed at the initial stage of weathering changes to an interstratification of Ca-vermiculite and biotite with counterbalanced change of biotite to an interstratification of biotite and Ca-vermiculite.
Electron microprobe analyses including the FeLβ/FeLα intensity measurment show that Low-K portions possess lower iron and Fe²⁺/(Fe²⁺+Fe³⁺) ratio than do High-K portions even in a single biotite grain from the fresh rock. Weathered biotite from saprolites shows low Fe²⁺/(Fe²⁺+Fe³⁺) ratios. Oxidation of Fe²⁺ to Fe³⁺ in octahedral sheet, presumably causes the iron and K loss to maintain local electrostatic balance, and results in the transformation of biotite into dioctahedral K·Mg-vermiculite. The K-Ca exchange in inter-layer sites took place simultaneously with the transformation of the K·Mg-vermiculite to an interstratification of Ca-vermiculite and biotite. This study demonstrates that oxidation of Fe²⁺ to Fe³⁺ in octahedral sites acts as the trigger for vermiculitization of biotite by weathering.

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