The petrography as well as major, trace and rare earth element (REE) compositions of Mesoarchaean Naharmagra quartzite of Aravalli Craton have been investigated to determine influence of sorting and recycling, source area weathering and provenance composition. The quartzites are mineralogically mature, medium to coarse grained quartz arenite with minor medium grained arkose. Petrographic analysis revealed that the quartzites were primarily derived from granite and metamorphic basement rocks of typical cratonic interior. All samples have SiO₂/Al₂O₃ > 10 (average ∼31), which indicates high maturity consistent with petrographical results. Quartzites are depleted in many major and trace elements due to quartz dilution. Many of the samples have undergone postdepositional K metasomatism. The calculated premetasomatic CIA values (46-92) indicate highly variable degree of source weathering compatible with non-steady state weathering. CIA and PIA values in combination with petrographic evidence favour intense chemical weathering probably under warm and humid climate. Provenance modeling indicates that the quartzites can be best modeled with a mixture having 50% tonalite-trondhjemite-granodiorite, 40% granite and 10% basalt. Probably, the sedimentation of these rocks took place in a stable and young cratonic basin evolved through accretion and tectonic amalgamation of pre-existing continental arcs comprising TTG and granitic bodies.

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Stability in seawater ⁸⁷Sr/⁸⁶Sr ratios over a glacial-interglacial timescale has gained the consensus, yet inter-site inconsistency exists in the previous data employed for validation of this issue. This study tests if the use of state-of-the-art Thermo Finnigan^TM TRITON multi-collector thermal ionization mass spectrometer (TIMS) can place more rigorous constraints on the seawater ⁸⁷Sr/⁸⁶Sr evolution at such a narrow timescale, by utilizing modern seawater, benthic foraminifera (150 ka-present) and corals (30 ka-present) (all sampled from the western Pacific realm). Application of a high-intensity setting (mass ⁸⁸Sr beam at 20 V) with internal and external precisions of ±0.000005 (2 SE) and ±0.000006 (2 SD), respectively, generates remarkably consistent 150 ka record of seawater Sr isotopes, such that 94.4% of foraminiferal ⁸⁷Sr/⁸⁶Sr data fall within a ±0.000006 envelope relative to a regression function. Undoubtedly the 150 ka ⁸⁷Sr/⁸⁶Sr trend exhibits no short-term, orbitally-paced variation. Meanwhile, unlike previous inference, our ⁸⁷Sr/⁸⁶Sr record cannot be attributed to a simple linear function, implying that higher-order, minor (amplitude ≤0.000010) ⁸⁷Sr/⁸⁶Sr oscillation might have been present on the timescale greater than glacial-interglacial cycle. Our observations are demonstrative data-based verification and improvement upon previous knowledge of the glacial-interglacial seawater ⁸⁷Sr/⁸⁶Sr ratios. We emphasize that high-precision ⁸⁷Sr/⁸⁶Sr analysis with the TRITON TIMS certainly enables us to discriminate minute Sr isotopic details of (paleo-)oceanographic significance.

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To evaluate the effect of slab-derived fluids from subducted Philippine Sea plate on mantle composition beneath southern Kyushu, we determined the boron (B) contents in basaltic rocks from Hisatsu volcanic province and Kirishima volcano, which erupted since 7.6 Ma. Since B is distinctively concentrated into slab-derived fluids, we have attempted to estimate the influence of subduction-related inputs on the composition of the sub-arc mantle based on the B systematics of the basaltic rocks. Old (7.6-0.4 Ma) basalts from Hisatsu volcanic province possess relatively low B/Sm (0.8-4.2), B/Zr (0.03-0.12) and B/Nb (0.6-2.5) ratios. In contrast, volcanic products from the comparatively young (<0.3 Ma) Kirishima volcano, located at the volcanic front, show significantly higher B/Sm (4-8), B/Zr (0.2-0.3) and B/Nb (3-5) ratios. In addition, basalts from these two regions show distinct trends on plots of Ba/Zr vs. B/Zr and Ba/Nb vs. B/Nb: the Hisatsu basalts have lower B/Zr, B/Nb and higher Ba/Zr, Ba/Nb ratios than those of the Kirishima basalts. These observations indicate that B-rich fluids from Philippine Sea plate were added to the mantle beneath Kirishima volcano between 0.4 and 0.3 Ma. Therefore the modern fluid input from the subducted slab to the subarc mantle may be limited beneath the volcanic front in this area.

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In order to elucidate the controlling factors for fluoride incorporation into coral aragonite (CaCO₃), we determined the ratio of fluorine to calcium (F/Ca) in coral skeletons collected from Pohnpei (Micronesia), Khang Khao (Thailand), Cebu (The Philippines), Tosa Bay (Kochi, Japan), Sakai Port (Wakayama, Japan), Tateyama (Chiba, Japan), Sesoko, Rukan-sho and Mizugama (Okinawa, Japan) using the ion-chromatograph method. The F/Ca (mmol/mol) ratio was highest in Tateyama with an average ratio of 6.04, whereas coral collected from Sakai Port, Tosa Bay, Okinawa, Cebu, Pohnpei and Khang Khao exhibited F/Ca ratios of 5.57, 5.02, 4.49, 4.24, 4.00 and 3.75, respectively. The factor controlling F/Ca ratio is discussed based on the proposed coprecipitation process of F in coral aragonite as the ion-exchange reaction: CaCO_3(s) + 2F^-_(aq) = CaF_2(s) + CO₃^2-_(aq). The equilibrium constant for the above equation can be expressed as: K_F´ = [CaF₂][CO₃^2-]/[CaCO₃][F^-]². In this paper, analyzed F/Ca ratio in coral shows a proportional change to calculated seawater [F^-]²/[CO₃^2-]. This finding suggests that F/Ca in coral skeletons is possibly controlled by carbonate ion concentration in seawater.

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Daisen volcano is located on the Quaternary volcanic front in southwestern Japan. The volcano is composed mainly of andesite and dacite, which chemically resemble adakites, with high Al₂O₃ and Sr/Y, steep REE patterns, and no negative Eu anomaly. (²³⁸U-²³⁰Th) disequilibrium (herein, a ratio in parentheses denotes the activity ratio) and trace element analyses of adakites from two volcanic domes, Karasugasen and Misen, indicate two adakite types. Adakite from Karasugasen is characterized by excess (²³⁰Th) over (²³⁸U), typical of most adakites, whereas adakite from Misen is characterized by excess (²³⁸U) over (²³⁰Th). The latter is consistent with enrichment in fluid-mobile elements relative to fluid immobile elements compared to rocks from Karasugasen. The values of (²³⁰Th/²³²Th) of adakites from Karasugasen and Misen are, respectively, around 0.75 and 0.81. These low (²³⁰Th/²³²Th) ratios result from the incorporation of subducted sedimentary material. The ratios, nevertheless, are higher than that for the estimate of lower crustal material suggesting significant incorporation of lower crust is unlikely. As adakites from Misen have (²³⁸U) excess over (²³⁰Th), adakite magma must have interacted with wedge mantle metasomatized by a slab-derived fluid, confirming the presence of a fluid-metasomatized mantle beneath Daisen volcano.

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The concentrations and distributions of dissolved free amino acids (DFAA) were determined in 31 hydrothermal fluid samples from the Logatchev field at 15°N and several hydrothermal vent fields between 4° and 9°S on the Mid-Atlantic ridge, sampled during three research cruises. The samples are derived from black smoker fluids with varying degrees of dilution, with end-member temperatures between 350 and 407°C, as well as of diffuse fluids with temperatures around 10°C. Most of the samples, even the hottest ones, contain significant amounts of DFAA and, with an average of 143 nM, more than in the deep water of the open ocean (below 50 nM, Lee and Bada, 1977). The highest values are found in diffuse fluids and the lowest in the hot fluids, but there are also some high-T fluids with high, as well as diffuse fluids with low concentrations. There are two larger groups of samples, distinguished by two different amino acid (AA) patterns: Group 1 has low concentrations in general, but relatively high concentrations of aspartic acid and glutamic acid, whereas group 2 has high abundances of aspartic acid, glutamic acid, serine, glycine, and alanine. The samples of the two groups do not share any other similarities, with the exception of their DFAA pattern. Thus, it appears that neither factor, such as fluid type or degree of dilution, influences the DFAA pattern, nor is the pattern site-specific. The presence of elevated AA concentrations in hydrothermal fluids implies that they are available as a nutrient source to vent organisms and as potential complexing agents for metals, possibly influencing their bioavailability and solubility.

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The BCR sequential extraction and EDTA single extraction method were applied to study the fractionation, concentration and bioaccessibility of the heavy metals in the sediment of Fenhe reservoir in North China. The sequential extraction schemes identify the non-residual metal among three basic operationally-defined host fractionations, namely, the soluble, exchangeable and carbonate bounded fractionation (F1), Fe-Mn oxides bounded fractionation (F2) and sulphide/organic matter bounded fractionation (F3). The metal extracted by the EDTA was defined as the bioaccessible fractionation (B) as well. The results showed the fractionation and concentration of heavy metals were influenced by the environmental condition. The bio-mineralization of natural organic matters in sediment as well as the microbial and chemical influence was the key factor controlling the distribution characteristics of different fractionations of heavy metals, including the dissolved iron content in the overlying water. The ratios of the sum of the three non-residual fractionations to the total concentration ((F1+F2+F3)/T) of Cd and Zn in the non-sterile sediment were higher than those in sterile sediment; the F2/T value of Pb was the highest, which was 25.12, 3.47 and 12.40 times as those of Cd, Zn and Cr respectively. The variation characteristic of (F1+F2+F3)/T value of Cr was particular compared to the other three heavy metals. The EDTA single extraction experiment showed that the ratios of the bioaccessible fractionation to total concentration (B/T) of Cd and Pb in sediment were high enough to 24.96% and 39.56% respectively, while those of Zn and Cr were both below 5%, showing slim bioaccessibility. Taking the high bioaccessibility of F1 fractionation into consideration, the elevated B/T values of Cd and Pb were confirmed by the significant linear regression existed between the value of F1/T and the total concentration. As for Pb, the positive linear regression equations between the value of (F1+F2+F3)/T (y) and B/T (x) in sediment was as follow: y = 0.9519x + 0.1265 (R² = 0.9289), which was different from other three heavy metals. The experiment results also indicated in the water-sediment interface, the higher potential environmental effect of heavy metal, the higher degree of the metal diffusion from the sediment to the overlying water, thus it will be a threat to drink water quality in the reservoir.

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Patterns of the entire range of REE in crude oils and coexisting water, collected from mud volcanoes in Xinjiang Province of China, are reported here for the first time. Crude oils show light REE enriched patterns with flat or depleted patterns in heavy REE, when normalized to chondrite. The REE concentrations in crude oils are larger than those in coexisting water by a factor of more than one hundred. Considering the hydrophobicity of oil and the high ionic characteristics of REE, it is strongly suggested that REE form complexes with ligands present in the crude oils. Based on the ¹³C NMR spectroscopy, it is found that small amounts of phenol and carboxyl groups are contained in the crude oil samples, which could possibly provide complexing sites for REE. REE patterns of crude oils are similar to those of coexisting mud samples collected from the same mud volcanoes, which suggests that the REE in crude oils are derived from rocks and sediments where crude oils were generated.

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Stable carbon (δ¹³C) and hydrogen (δD) isotopic compositions of n-alkanes in total suspended particles from Tokyo were measured to decipher their source and transport in the polluted urban atmosphere. The δ¹³C and δD values of the C₂₁ to C₃₃ n-alkanes ranged from -25.5 to -32.8‰ and -55 to -157‰, respectively. The δ¹³C values are within the range of those in terrestrial higher plants and fossil fuel. In contrast, the δD values of the C₂₁ to C₂₄ n-alkanes and the C₂₆ to C₃₂ even-carbon numbered n-alkanes are in the range of those typical to marine crude oil, indicating that these n-alkanes are primarily derived from the anthropogenic emission of petroleum hydrocarbons. Lower δD values were found in the C₂₅ to C₃₃ odd-carbon numbered n-alkanes than other homologues, suggesting that the long chain n-alkanes are significantly contributed from terrestrial higher plant waxes in addition to fossil fuel hydrocarbons. The δD values of the C₂₉ and C₃₁ n-alkanes show a strong negative correlation with CPI (carbon preference index), which enable us to eliminate fossil fuel contribution using a mass balance approach. Large seasonal variations in the δD values corrected for fossil fuel contribution and their relation to seasonal differences in air mass transport suggest that terrestrial higher plant-derived n-alkanes in the Tokyo aerosols likely originate from the raw leaves of local vegetation. The corrected δD values based on CPI of 10 are in good agreement with those in contemporary vegetation in Tokyo, indicating that local vegetation is more important as a source of terrestrial higher plant-derived n-alkanes in the polluted urban atmosphere.

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We report results of a 9-year monitoring program that took place from 2001 to 2009 of the helium and carbon isotope (³He/⁴He, δ¹³C) and relative abundances ratios (CO₂/³He) of fumarole sites at Poás and Turrialba volcanoes, Costa Rica. Over the monitoring period, helium isotopes (³He/⁴He), δ¹³C_(CO2) and CO₂/³He values varied between 6.7-7.6 R_A (where R_A = 1.4 × 10^-6), -5.5 to -1.3‰ (vs. PDB) and 8.2-59.5 (×10⁹), respectively, at Poás Volcano. Corresponding values for Turrialba Volcano were 6.9-8.0 R_A, -4.4 to -2.7‰ and 9.4-19.6 (×10⁹), respectively. Notably, fumarole sites at both volcanoes underwent changes in temperature, intensity and areal extent during the 9-year period, and Poás Volcano experienced hydrophreatic eruptions and structural damage induced by a nearby earthquake. At both volcanoes, there were significant and sympathetic temporal changes involving all three geochemical parameters—notably in 2001 and 2006 at Poás and in 2001 and between 2005-2007 at Turrialba. We dismiss increased hydrothermal interaction, magma degassing and calcite precipitation as likely causes of the observed variations. Instead, by ascribing endmember compositions to the three principal contributors to the CO₂ inventory—mantle wedge as well as limestone and organic (sedimentary) carbon (both slab and crust derived)—we show that changes in observed He-CO₂ relationships mainly reflect enhanced crustal contributions of CO₂ and increased inputs from magma degassing. Such changes in the relative roles of crust and magma as suppliers of CO₂ are readily apparent in the He-CO₂ temporal record. This work supports calls for long-term geochemical monitoring to be included within hazard assessment and mitigation studies at active volcanoes.

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A simple and efficient method for measuring CO₂ concentration of deep water of gassy lakes is proposed. This method is based on the gas self-lifting in a plastic hose that is deployed into deep water of the lake. Physical parameters such as the volumes of separated gas and water, and their temperature were used to obtain CO₂ concentration of lake water on site. We can measure the CO₂ concentration as long as the gas self-lifting continues. Sampling depth can be easily changed little by little by pulling up the hose with a calibrated stainless steel wire. Thus, we can obtain data from finely separated depths. Here we present the CO₂ profiles obtained by using the present method in 2007 and 2009 at Lakes Nyos and Monoun, Cameroon, to demonstrate its applicability on gassy lakes. Sharp reduction of CO₂ content at Lake Monoun, and gradual reduction at Lake Nyos as a result of degassing operation were clearly shown by the current method. This gas self-lifting method can be efficiently used to monitor gassy lakes.

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