The hornblende quartz dacite is one of the very rare hornblende-bearing rocks in the Bonin Islands. The dacite has a high SiO₂ Content of 72.0 wt.% corresponding to rhyolite, but the Cr content is high, 50 ppm, a value of average andesite. It consists of phenocrysts of plagioclase (8.6 vol.%), quartz (3.9%), orthopyroxene (2.2%), green hornblende (1.8%), clinopyroxene (1.2%) and magnetite (0.4%) in the groundmass of feldspar, pyroxene, amphibole, iron ore and glass. The majority of the hornblende phenocrysts are magnesio-hornblende with 9.29–5.67% Al₂O₃, 1.12–0.45% TiO₂, 1.77–0.93% Na₂O, < 0.05% Cr₂O₃ and 58.5–68.4 Mg#, which are similar to those in diorite from Palau. The clinopyroxene phenocrysts have Mg# and Cr₂O₃ as high as 84.4 and 0.45%, respectively, suggesting that they have crystallized from a more primitive magma with higher MgO and Cr, whereas the orthopyroxenes are mostly hypersthene. The dacite also contains plagioclases having unusually high An contents of 86.8 to 42.6, despite its high SiO₂. The hornblende quartz dacite seems to have derived from a high-Mg andesite magma crystallizing clinopyroxene prior to orthopyroxene, which is different from most boninite magmas that have crystallized protoenstatite and/or bronzite following olivine. Crystallization of the magnesio-hornblendes suggests that the hornblende quartz dacite has been cooled slowly in a magma chamber at depth, in the sharp contrast with rapid quenching from > 900°C of the boninite series rocks.

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Pelitic gneisses and schists containing minerals insoluble in hydrofluoric acid such as staurolite, andalusite and others, and igneous rock reference samples of the Geological Survey of Japan (GSJ) were decomposed by the method of Crock et al. with fuming process of hydrofluoric acid after fusion using LiBO₂ to remove Si which tends to form a gelatinous precipitate. However, they often left residues.
To get a clear, stable solution of these rocks, the method of Crock et al, was modified: better results were obtained by repeated drying of the residues by adding a mixed solution of HCl, HClO₄ with a little more water in the process of the expulsion of residual fluorine. The contents of Al, Fe, Mg, Ca, Ti, Mn and Zr in the metamorphic rocks and the GSJ igneous rock reference samples were determined by means of an inductively coupled argon plasma/optical emission spectrophotometer, and the Na and K contents by atomic absorption spectrometry.
The results of chemical analyses for the GSJ igneous rock reference samples decomposed by the modified method show the reasonable values for the major elements (except Si) and Zr.
The results of analyses of the pelitic gneisses and schists, containning the minerals resistant to hydrofluoric acid (HF), decomposed by both the modified method and mixed acid show that this modified method is available in analyses of the major elements and Zr for the metamorphic and igneous rocks bearing the minerals resistant to HF.

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Mineral separation in carbonate group of minerals is a difficult task, and often resolved by staining technique. Feigl’s solution and Meigen’s solution are commonly used for distinguishing aragonite from the carbonate, the former stains black and the latter stains purple on the aragonite surface, while calcite and other carbonate species are changeless during staining treatment with each solution. Hence, we report a refined staining technique to separate aragonite from calcite using Meigen’s solution. This method has advantage in obtaining 100% pure mineral separation for high precision of micro scale isotope analyses. As an example, we analyzed calcite-aragonite pairs from carbonate chimneys and found interesting isotopic results. Especially, radiocarbon activity in coexisting calcite and aragonite is significantly different, and this result suggests the presence of entirely different fluid source for calcite and aragonite precipitation.

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The behavior of sand vary hydro-dynamically with the Reynolds Number range from 1 to 1000 for grain size and settling velocity, corresponding from laminar flow to turbulent flow. Hydrodynamic analyzer is newly developed using small inner diameter settling tubes, four sets of photo-detector, and computerized auto-handling and analysis, for the reconstruction of the sedimentary environments based on the special hydrodynamic characters of sand and sandstone. The four detectors can measure the changes in the settling velocities just after the sample is dropped and caused by the hydrodynamic interaction with small inner diameter tube.
The analyzed results are shown on the computer display during the analysis. The analyzer is enough compact to use at sampling field and field station. The photo-detector is composed of high luminous emission diode and phototransistor. Logarithm of the detected signal of phototransistor corresponds well with the amount of passing sand grains. The dispersion correction is made on the detected signal for the distances from falling position to detectors.
The glass beads experiments show that settling velocity can be converted to the grain-size using equations of Stokes, Allen, Karman and Newton. Two equations for the conversion are inserted into the four equations, based on the relation of the flow resistance and Reynolds Number. Using these equations, weight base contents are calculated from the detected signals.
The measurements using the new analyzer show following results. 1) The grains of beach sand from the surf zone have normal distribution for the settling time, not for the logarithm of the grain size. 2) The sandstone of the submarine fan-delta sedimentary sequence in the North Fossa Magna can be classified into five types using the grain-size distribution on the logarithm of the grain size and hydrodynamic behavior. 3) Special behaviors are detected in the hydrodynamic behavior for turbidites and sediments with strong bioturbations in the submarine fan-delta sedimentary sequence.

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Automatic laser ranging has been started systematically to monitor the activity of the Kusanagi and Asabata faults along the laser paths from the Crustal Activity Observatory of Shizuoka University to Yatsuyama, Yambara, Torisaka and Shizuhata. The Udo Hills is tilting northwestward along the Kusanagi Fault and Asabata Pond is subsiding along the Asabata Fault by large-scale gravity collapse. The basal part of the collapsed Udo Block is riding on the subducting Philippine Sea Plate along the Suruga Trough. Tilt model along the faults was established and compared with the topography and geology. The gravitational collapses occurred on the northeastern corner of the submarine fan and delta body from the Abe River. The Kusanagi and Asabata faults are member of the multiple collapse system, and the other members are estimated at the southeast margin of Udo Hills.
Systematic offsets have been detected by comparing air temperature calculated from laser ranging data with the surface air temperature at the Shizuoka Station of the Japan Meteorological Agency. The offsets relate to the changes in the distance of the laser paths, caused by the crustal movement. The amount of the changes is more than several cm in laser path distance. The maximum distance appeared in the middle of April 1998 just before the earthquakes to the east off Izu Peninsula, and the minimum distance appeared in the early January 2000 after the Taiwan Earthquake of September 1999 for Yatsuyama and Yambara laser paths. The distance of the Yatsuyama path increased from March 2000, then decreased in the end of September 2000, which might be related with the earthquakes and eruption of Miyake Island and earthquakes near the Niijima-Kozushima.

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The study of biological micro-particles in rain water have hardly ever published because sampling, storage and measurement are difficult tasks to perform without contamination. This study carefully carried out laboratory experiments and field works at three sites (Shizuoka University, Mt. Fuji and Mt. Norikura). Biological particles in rain water were found to be bacteria and other organisms or organic debris such as spore, pollen and leaf debris. The purpose of this study is to measure the number of bacteria exactly. In order to perform this purpose, more examination of sampling, storage samples and measurement without contamination is required. An alternative approach is to stain the bacteria with DAPI and enumerate them by epifluorescence microscope. As a result of laboratory experiments, the blank of sampling and measurement was about 7.4 × 10³ cell/ml. And then, the concentrations of atmospheric samples at three sites were 2.0 × 10⁴ to 4.8 × 10⁴ cell/ml in rain water. Therefore, 13 to 27% of the total concentration in rain water as a background value was comprised, which comes mainly from Milli-Q water. And then, according to laboratory experiments, the error of counting bacterias was ± 1,000 for 18,000 (± 6%). It was confirmed on the measurement for bacteria in rain water.

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To understand the cycling of marine compounds cross flow ultrafiltration with organic membrane has been extensively used as an isolation tool to study colloids in seawater. Because organic membrane has given some contamination, a large volume sample was used for reducing contamination. Use of inorganic membrane was expected to use cross flow ultrafiltration system. Recently porous glass filter was developed as an inorganic membrane. This porous glass has specific characteristics such as high porosity, narrow width of size range, and precombustion. First, we examined a flow rate of this system and to reduce carbon free by precombustion. Second we tested recovery with a size of 30 nm to use two different organic compounds: Vitamin B12 (MW = 1,335), Bluedextran (MW = 2,000,000). At last we used this system for isolation of organic colloids from seawater. We found a optimal flow rate of this system was 0.5–1.0 (ml/min), and precombustion temperature was 600°C for removal of organic contamination. Vitamin B12 could easily pass through 30 nm porous glass filter, but Bluedextran could not pass through it. We confirmed this membrane can use for separation effectively. And most of DOC in seawater of Suruga Bay could pass through 30nm porous glass filter. Only 10–20 (%) of DOC was retantated by 30 nm porous glass filter. Thus a large amount of DOC in Suruga Bay was composed of a low molecular weight fraction.

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A new type inorganic membrane-porous glass is applied for both cross-flow filtration modes. The laboratory results show that permeation of Albumin passing through 30 nm porous glass filter can be negligible (< 0.015%). The filtration behavior of natural DOC consistently shows a decreasing concentration in the permeate with increasing CFs. Thus, the permeation of HMW molecules is minimal during CFF using porous glass filter, even under high CFS (CF > 50). During filtration of Bora Bay seawater, OC concentration of permeate (C_p) first is at very beginning (i.e. in the first liter of permeate) higher than the OC concentration of pre-filter sample, and then lower and lower with permeate volume and concentration factor increasing. The speed of OC concentration decreasing is very rapid at beginning. After the CF > 4 using regular concentration mode and after CF > 12 using diafiltration mode, the variation of C_p becomes slightly as CF continuously increased. Thus, the organic matter of Bora Bay seawater can easily pass through 30 nm porous glass filter, in another word, a large amount of organic matters of Bora Bay seawater can not be retained by 30 nm porous glass filter. The results show that major organic matters of Bora Bay seawater are smaller than 30 KDa.

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