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Lead in the skeleton of annually banded coral, Porites c.f. austrariensis, from Shiraho, Ishigaki Island was detected. As a result, a tendency was seen that on and after 1980's, it takes higher value than previous. Lead is released to the atomosphere by consuming of fossil fuels. From two fact that the sampling point locates leeward of China inthe winter seasonal wind, and that China has been accomplishing very rapid economical growth since 1980's, the increase of lead in coral skeleton is a reflectiono of rapid increase of the use of coal in China.

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The uranium ratio in the rocks of limestone area from Okinawa main island shows 0.95-1.44. Recently, high ²³⁴U/²³⁸U activity ratio of 3.25 was found in the rock from Aha sample in northern area of Okinawa main island.
The thorium, uranium isotopes and their daughter nuclides were analyzed in the rocks from Aha. The iron(_II_)/(_III_) ratios and rare earth elements were also measured to verify redox state in the rocks and a radioactive disequilibrium was discussed.

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In situ U-Pb zircon geochronology of migmatitic gneiss and granitic orthogneisses from the interface of the Arabian Nubian Shield and the Mozambique Belt in the central part of the East African Orogen, western Ethiopia, were studied using SHRIMP to constrain the contributions of older crustal materials and to trace back the nature and evolution of their source rocks.

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We present noble gas data was mantle-derived xenoliths collected from the Cenozoic volcanic by crushing from the five typical Cenozoic volcanic provinces(Kuangdian, Yitong, Huinan and baitoushan, Longquan and yitong) beneath Northeastern China. The 3He/4He ratios within each volcanic province are various with ranges of 12.52-15.78Ra, 3.06-9.10Ra, 6.08-9.18Ra, 7.14-7.71, and 5.87-6.00Ra times the atmospheric ratio (Ra), respectively. the lager variations of 3He/4He ratios shown that the geochemical and isotopic in this SCLM is very heterogeneity, with integrate to the Ne and Ar isotopic components. We suggest that the present lithosperic mantle was formed via the multiple stages of mantle presses which consider to the formed age of lithospheric mantle.

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Dating of frictional rocks are very difficult to analyze, because the closure temperature is different from each mineral what any rock is composed such minerals. Radiometric age should be detected as cooling age (=closing age), and thermal history for geologic event, which is calculated from temperature ascent and its temporary variation, is connecting and investigating quantitative analysis. It is expected as a good tool that a sensitivity mineral of thermal rising should be applied such geological event as fault movement for frictional thermal.

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Techniques have been developed to measure Sr isotopic composition and concentration on a single sample aliquot in rock and water samples with ⁸⁴Sr-concentrated spike. A single TIMS measurement of the Sr sample yielded both isotopic composition and concentration after decomposition of mixture of sample and ⁸⁴Sr spike. Standard solutions with different Sr concentrations, made form Johnson-Matthey Specpure SrCO₃ (99.999%), were added by appropriate amount of 84Sr spike solution, and determined the Sr isotopic composition and concentration. The single measurement was adopted to water samples of an Indian river and standard rocks such as JP-1 and JCh-1. We will report the results.

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Taketomi submarine hot spring is located at 20m depth in 500 m east of Taketomi island. Here is the hot spring fluid (about 54 degrees Celsius) and gas (mainly composed of methane) venting.
In general, the hydrothermal fluid seems to be caused by the reaction between the hot volcanic rocks and recharged seawater and/or meteoric water. However, there is not apparent Quaternary arc volcanism in the Ryukyu island arc, which remains the question that the heat source of this hot spring.
In this study, we will carry out the geochemical study on the sediment core samples collected from the hot spring to clarify the geochemical characteristics of this hot spring.

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The YK04-09 cruise using R/V Yokosuka and manned submersible SHINKAI 6500 was carried out on the Valu Fa Ridge in Lau basin. We found the 86^oC simmering at the Vai Lilli site where the high temperature black smoker chimney was confirmed in 1989. In addition, the active black smoker with 360^oC was newly discovered at the Mariner site which located at the ~5km north area from Vai Lilli site. In this study, we determine the chemical composition, mineral composition, and precipitation age of hydrothermal chimney deposits collected from Vai Lilli and Mariner site. Based on these results, we will clarify the geochemical characteristics of the hydrothermal chimneys in Lau basin, and the temporal variation of hydrothermal activities in Vai Lilli and Mariner site.

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Tono uranium deposit has been studied as natural analogue on geological disposal of high-level nuclear waste. However, the previous studies have focused on the migration of U in micro-scale and the migration of elements in the mining scale(several km X several km) has not studied. In this study, many samples were collected from top to the bottom of sedimentary rocks, and were analyzed for mineralogy by XRD, for major elements by XRF, and for minor elements by ICP-MS. Besides that, clay fraction of the samples was analyzed for minor elements by ICP-MS and for major elements (REE etc) by ICP-AES.

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Humic acid (HA) exists widely and affects redox reactions in the environment. Many researches on redox reactions between HA and metals are carried out. Fe(III) forms a complex with HA. When Fe(III)-HA complex is irradiated, Fe(II) generates. Fe(II) reacts with hydrogen peroxide and produces OH radical. OH radical is strong oxidant and destroys contaminants, such as organic compounds. So it is important for understanding a behavior of OH radical to study the mechanism of Fe(II) photoformation. We conducted irradiation experiments using iron which exists in HA. When HA solution was irradiated, Fe(II) generated. A Fe(II) photoformation rate was fast, and total dissolved iron concentration was high. Then, photochemical behavior of iron was investigated using iron which exists in commercial HA.

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As a part of study for the utilization of humic substances as an environmental indicator of the coastal region, humic acids were extracted from three points of the surface sediment of the Sone tideland located near the new Northern Kyushu airport. Various structural analyses (NMR, UV, IR, py-GC, elemental analysis) were performed to the extracted humic acids, and the relation of structral features of humic acid and several environmental factors were investigated.

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Changes in gas concentration (Rn, He, Ar, CO2, CH4, H2, N2, O2) in soil gases along active faults in relation to earthquakes were reported in the literature worldwide. Also changes in gas concentrations from thermal springs and dissolved ions in thermal water were studied in some countries. This research was carried out in thermal springs for the following reasons: because they are representative of deep water circulation, because free gases in thermal water are less contaminated with atmospheric air, and because they are much less influenced by meteorological parameters in comparison to soil gas. We will present the results of radon concentration changes in thermal springs of Slovenia and ground water of Japan.

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Degradation of groundwater quality in the Sichuan Basin was studied, based on the major element chemistry and stable isotopic ratios of sulfate-sulfur and nitrate-nitrogen of groundwater and surfacewater collected from the four cities along the Minjiang and Yangtze rivers. The degradation of groundwater quality was due to anthropogenic sulfur and nitrogen contamination. Although air pollutant is the dominant source, the contributions of household waste water and industrial effluent increase toward downstream. Agricultural activities is another source, however, it influences only the local groundwater in the farmyard.

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150 groundwaters, sampled from 16 different villages of Lahore and Kasur districts, Punjab Pakistan, contain As exceeding the WHO standard (10microg/L) and reaches up to 2483 microg/L. The highly arsenic concentrated samples were obtained mostly from shallow hand pumps of 20-27m depth, and those are characterized by basic pH up to 9.5 and high SO4 up to 1200 mg/L. The sulfur isotopes values range from 4.8 to 6.7 with mean of 5.6. Arsenic speciation showed the As is in As+5 state. The spatial distribution of As-rich shallow groundwaters indicates either direct contamination from some anthropogenic source like coal combustion, or use of fertilizers. This paper reports the chemical characteristics of this newly reported contaminated groundwater and possible sources and mobilization of As.

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