Mineralogy and fluid inclusion of seafloor hydrothermal chimney and sulfide ore from Iheya North Knoll seafloor hydrothermal system, Okinawa Trough were studied. Homoginization temperatures of sphalerite are higher than the temperature of present hydrotehrmal fluid, indicating that the past activity of the system was more active than the present day. Salinities of fluid inclusion are higher than seawater, suggesting the past activity emitted brine rich fluid. The center of the past activity seems to be the same as that in the present day. However, the temperature of the hydrothermal fluid seems to decrease at the peripheral area. The degrees of temperature decrease are different in NS and EW closs sections.

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The SWEEP VENTS dive program using SHINKAI6500 conducted in Nov. 2004 studied hydrothermal systems in the Valu Fa Ridge, Lau Basin. Geochemical studies of hydrothermal fluids revealed strong acidity and high metal elements concentration. The Vai Lili field show significant decline of the activity.

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[in Japanese]

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Analysis of the chemical ingredient of hydrothemal plume, a thing by water intake in hydrocast was the mainstream till now. However, the chemical sensor which is installed in ROV enabled spot measurement.In this study, chemical behavior in hydrothemal plume was examined comparing consecutive data with in-situ chemical sensor and the spot data by water intake.

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[in Japanese]

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We purified an extracellular enzyme that oxidizes Mn(II) to insoluble Mn oxides, from the spent media of Acremonium sp. KR21-2, and characterized enzymatic Mn(II) oxidation process by KR21-2. In-situ XANES shows that Mn(IV) is the main component of the biogenic Mn oxide during the oxide formation by the purified enzyme. TEM observation shows that the biogenic Mn oxide has a phyllomanganate structure.

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[in Japanese]

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The annual wet and dry deposition fluxes of 12 trace elements (i.e., As, Cd, Cr, Cu, Hg, Mn, Mo, Ni, Pb, Sb, Se and V) were measured on the basis of one year of observations (December 2003 to November 2004) at 10 sites in Japan. Precipitation and dry deposition (gases and particles) samples were collected every half-month using an automatic sampler, which is composed of a precipitation sampler and a water surface sampler for dry deposition. In this paper, the annual wet and dry deposition fluxes of the above trace elements in Japan are presented for the first time, and factors contributing to their regional variations are discussed. In addition, sources of the deposited lead are evaluated on the basis of lead isotope ratios in the precipitation and dry deposition samples.

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In Tokyo Bay, the concentrations of dissolved gaseous mercury in the surface seawater and total gaseous mercury in the air were measured. Based on these data, the evasional fluxes of mercury from the sea surface were estimated by using a gas exchange model. In addition, by using an automatic wet and dry deposition sampler the wet and dry depositional fluxes of mercury were also measured in and near Tokyo Bay. The results suggests that the surface seawater was supersaturated with gaseous mercury and the evasional flux of mercury was comparable to the depositional flux in Tokyo Bay.

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(1)Recently it is considered about CO2 in air.But young student have low sence,because of they have low knowledge and technique.(2)There is some technique to determin CO2ppm accurately.(3)We mesure CO2ppm in schoolyard,and open data on internet site.(4)Through our 3years study,plant activity make it low,but after school it effect little.In our site,the program were made by Mr HAMANO Shogo,alumnus of Musashi HS.

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Total concentrations of Al, Fe, Mg and Ba in an ice core from the Dome Fuji station, Antarctica were measured and analyzed with previously obtained data of the oxygen isotope ratio, the dissolved concentration of metal and the particle concentration. The total concentrations of metallic elements were relatively high in the late of glacial periods and low in the interglacial periods. The ratios of the dissolved concentration to the total concentration were high in the begin of terminations. The aerosol fluxes estimated from the concentration of Al in the ice core were 4-15mg m^-2 yr^-1 in the period of late glacial and 0.3-3mg m^-2 yr^-1in the period of early interglacial.

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We collected the size fractionated aerosol and wet deposition at the bottom of boudary layer and the top of boudary layer during the Asian dust events in Hokkaido. We found the same size distributions of insoluble mineral dust particle in both heights. The concentraitons of water-soluble components and insoluble particle in the wet deposition at the bottom of boudary layer were higher than those at the top. The size dependece of scavenging ratio of mineral dust particle by rainout was consistent with washout.

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[in Japanese]

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We analyzed sedimentary photosynthetic pigments in HDP-04 core from Lake Hovsgol, Mongolia, to investigate historical trends of primary productivity in the lake. HPLC analysis shows that chlorophyll derivatives such as pyropheophytin a and steryl chlorin esters, and algal carotenoids such as zeaxanthin, lutein and beta-carotene are well preserved in the core. Besides algal pigments, bacterio-chlorophyll e and isorenieratene, characteristic pigments of phototrophic green sulfur bacterium, were detected at the depth of 18 and 20 m.

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[in Japanese]

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The Quaternary red earth soils cover wide areas of southern China (Hunan, Zhejian Province etc). We present the geochemical characteristics of red earth soils, such as major element composition, REE, Sr and Nd isotope composition, and discuss their origin.

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Migration behavior of minor and rare earth elements in acidic soil such as andosol,loam and red soil was studied.The difference in the mobility of these elements may be caused by the different soil constituent minerals. Especially, the mobility of the rare earth elements is greatly dependent on the type of the clay mineral in the soil.This may be also related to different hydrated ionic radii of each rare earth element.

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[in Japanese]

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The Sr-90 and Cs-137 concentrations in environmental samples were determined during 1963-1999 in Japan. The concentrations in precipitation decreased suddenly after the last atmospheric nuclear weapon test in 1980, and one sharp peak of Cs-137 due to the Chernobyl accident in 1986. The 90Sr and 137Cs cumulative depositions by precipitation have maximum values of 2,600 MBq/km2 and 3,700 MBq/km2 in 1965, respectively. 27% of Cs-137 and 51% of Sr-90 were removed from soil during 1980-1999. Higher 90Sr observed in river water due to removing of 90Sr from soil. Comparing cumulative depositions by precipitation and concentrations in seawater, the removal rate of Cs-137 was during 1980-1999 about 1.2 times, documenting more Cs-137 was removed to seabed sediment, and more Sr-90 came to rivers.

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[in Japanese]

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A study was conducted to investigate behavior of Al and DOC in acidic red soil-impacted estuary at Gesashi mangrove estuary. Results showed that the highest concentration of Al in the river water was 0.17 mg/L and tended to increase with salinity to maximum value of 0.452 mg/L in the seawater. The highest DOC concentration was 2.76 mg/L in the river water and it slightly increased in the mangrove zone to maximum value of about 3 mg/L. However the DOC slightly decreased with salinity to about 1 mg/L in the seawater. Red soil showed a considerable contamination to the Gesashi mangrove estuary. The soil suspended particulate matter with adsorbed Al is transported from the river to the estuary and serve as a source dissolved Al in the water by exchange process.

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Recently,the pollution by nitrate nitrogen in environment water is a serious problem.The load to the environment is small for removal of nitrate nitrogen using the biological treatment method.This time,the basic studies on the removal of nitrate nitrogen using immobilized denitrifying bacteria was carried out.

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Mid-ocean ridge basalts (MORBs) of the Indian Ocean have been well known to differ in Sr-Nd-Pb isotopic composition from those of the North Atlantic and East Pacific Ocean, and they have been assigned to the DUPAL anomaly. It has been expected that non-traditional Li isotopic data provide complementary information to radiogenic isotopic data such as Sr, Nd, and Pb, regarding the nature of mantle geochemical heterogeneity. Based on the Li isotopic compositions of the DUPAL source, we argue that the Li isotope data support the recently proposed idea that significant amounts of recycled lower continental crust as the cause of the Indian Ocean DUPAL anomaly.

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On the chemical state of the Earth's interior,more than 4 geochemical endmembers have been inferred from solid element isotope ratios such as Sr,Nd and Pb in magmas. On the other hand, noble gas isotope ratios also suggest at least 4 geochemical endmembers. However, they do not always correspond one another. Because their characteristics are different and solid element isotope ratios reflect those of mantle differentiation, whereas noble gas isotopes those of degassing degree. Each geochemical endmember should reflect the chemical evolution of the Earth. Hence,it becomes possible to give some constraints on the chemical structure and evolution of the Earth's interior to take the significance of isotope ratios of each endmemeber into accounts.

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Re-Os isotopic composition and elemental abundances for 11 samples from the 4-km thick section of Ontong Java Plateau crust in Central Malaita, Solomon Islands that were previously analyzed for Pb-Nd-Sr isotopes were recently acquired. Our results show that the two-types of lavas recognized by distinct Pb-Nd-Sr isotopic compositions also show distinct Re-Os isotopic compositions. Singgalo-type lavas have slightly elevated 187Os/188Os values than those of the Kwaimbaita-type lavas. This presentation will discuss: 1) possible explanations for this difference, and 2) some implications of the new data on the origin of the plateau

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Hawaiian mantle plume is thought to originate at considerable depth and, therefore, may provide a window into the deep mantle including the lower mantle and possibly the core-mantle boundary. Geochemical study of Hawaiian lavas is one of the most important ways to understand the origin of Hawaiian mantle source components, and the convection of materials in the Earth's interior. Numerous geochemical studies have shown that more than three mantle source components, Namly: the Kea, Koolau, and Loihi component, are present in the Hawaiian mantle plume. Isotopic and trace element ratios in Hawaiian lavas suggest that a recycled oceanic crustal component and a component from the lower mamntle are dominent in the Hawaiian mantle plume.

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IAB irons are one of a few types of iron meteorites that contain silicate inclusions. Caddo County IAB iron meteorite includes silicate inclusions rich in Na-rich plagioclase and diopside, which is classified as andesite. The andestic material can be an early partial melt product of chondritic materials. This indicates inhomogeneous segregation of partial melt of andesitic silicate and Fe-Ni-S metal from chondritic source occured even in a small planetesimal. This further implies that building block of terrestrial planets are not only chondritic materials, but also such inhomogeneously segregated partial melts from chondritic sources.

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We report the discovery of abundant hematite in Archaean greenstones in a deep drill core from the Pilbara Craton, Western Australia. The greenstones are mostly composed of basaltic rocks that primarily erupted on the seafloor about 3.46 Gyr ago, and were exposed before 2.77 Gyr ago and subsequently covered by a continental flood basalt. We have obtained a Re-Os age of 2,763 +/- 15 Ma on pyrite veinlets that clearly cross cut (younger than) the hematitized greenstones. Geologic history of the Pilbara district and geochemical data on the hematitized greenstones (including an oxygen isotope value of ca. 0 permil for hematite separates) suggest the hematite was formed by reactions with O₂-rich surficial water and thus an oxic atmosphere developed before 2.76 Gyr ago.

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Hydroxyl radical (OH radical) is appreciated to be the strongest oxidant in the atmosphere. OH radicals play an important role in the chemistry (oxidative reaction) and composition of the troposphere because of its high reactivity. But, OH radical concentration and production processes of OH radical in aerosol particle have not been understood well. Based on the measurement of OH radical photo-formation in aerosol particles at Okinawa Island, we tried to resolve oxidation reactions in aerosol particles during their transportation. The purposes of this study were; 1) to measure OH radical photo-formation in aerosol particles, 2) to estimate the rates and 3) to understand the mechanisms of OH radical photo-formation in aerosol particles.

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[in Japanese]

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In this study, we collected atmospheric aerosols by High volume air sampler in Okinawa Island. And, we measured carbon compounds such as OC, EC, and CC using CHN coder.The mean concentrations of OC, EC and CC were 0.81, 1.29 and 0.05 microgram/cubic meter, respectively. OC and EC showed seasonal variation.

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