Naphthalene and its methyl homologs were found in Miocene to Pliocene sediments of the Shinjo basin. The total concentrations of naphthalenes ranged from 26 to 5, 700 ng g^-1 from the top to the bottom sediments of an about 1, 600 m thick sequence. Naphthalenes were mainly distributed in the Kusanagi Formation and their depth profile showed a characteristic feature, indicating a concentration peak at the onset of oil-generation layer. The ratio of 2- to 1-methylnaphthalene as well as the relative abundance of dimethylnaphthalene isomers, except for 1, 8-isomer, showed no depth dependence. Therefore, it seems that no significant isomerizations of the naphthalene homologs had occurred during the burial diagenesis around and above the oil-generating zone in the sediments. However, as to the least stable 1, 8-dimethylnaphthalene isomer, the negative logarithmic change of the relative abundance of the isomer (Alexander et al., 1984) was observed showing a trend of increasing with depth.

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The Sullivan deposit of British Columbia, Canada represents an ancient submarine hydrothermal system that formed a giant Pb-Zn-Ag massive sulfide deposit. Tourmaline is abundant in the deposit and acts as a good tracer that may reveal the nature of the original hydrothermal fluids and ore-forming processes, due to its refractory characteristics. Concentrations of Zr, Hf, Nb, Ta, U and Th in tourmalinites from the Sullivan deposit and its general surrounds are analyzed using the ICP-MS technique. Although concentrations of these elements are highly variable, good correlations exist between Zr and Hf, Nb and Ta. Tourmalinites from the Sullivan hanging wall and shallow footwall near the massive sulfide orebody have generally higher Zr, Hf, Nb, and Ta values than do deep footwall and regional tourmalinites. A significant U enrichment has been documented in the hanging wall and shallow footwall samples. It is proposed that the different concentrations and correlation patterns of these so-called immobile elements in the Sullivan hydrothermal system in fact reflect mobility of these elements influenced by different geochemical processes such as protolith control, hydrothermal leaching and mixing of seawater with rising hydrothermal fluids.

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SHRIMP analyses have been conducted for rock samples from the Koongarra secondary ore deposit in Northern Australia to obtain activity ratios of ²³⁴U/²³⁸U and isotopic ratios of ²⁰⁷Pb/²⁰⁶Pb and ²⁰⁴Pb/²⁰⁶Pb and to understand their migration behavior within the secondary ore deposit. Main target minerals for the analyses were iron minerals and kaolinite, which are the main weathering products in this area. The activity ratios of ²³⁴U/²³⁸U were based on SHRIMP counts at the mass of uranium metal. The ²³⁴U/²³⁸U activity ratios based on counts of uranium oxides were not satisfactory, because the count rates of ²³⁴U¹⁶O were affected by interference from the ²³⁸U¹²C fragment. The activity ratios of ²³⁴U/²³⁸U were approximately unity for crystalline iron minerals, whereas the amorphous iron minerals (precursors of the crystalline iron minerals) had also values above unity. The mean residence time of uranium within the iron nodules was estimated to be up to approximately 2–3 million years. Results of lead isotopes, represented by a diagram of ²⁰⁷Pb/²⁰⁶Pb vs. ²⁰⁴Pb/²⁰⁶Pb, indicated that the present three samples contained radiogenic lead, common lead and mixture of both components. In addition, the recent radiogenic lead component within the primary ore is dominant in the area closer to the primary ore. The radiogenic lead isotope compositions of samples at greater distances from the primary ore have been affected only by the earlier mobilization event of radiogenic lead. All these results indicate that some geologic event causing migration of the radiogenic lead had occurred before formation of the secondary ore deposit due to the weathering. After the weathering commenced at least 2–3 million years ago, uranium and lead have migrated from the primary ore. While the uranium has dispersed throughout the secondary ore deposit, the lead reached only the area closer to the primary ore probably due to its immobility compared to the uranium.

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Major and trace element and Nd and Pb isotopic compositions of volcanic rocks from the Sanchazi (SCZ) block of the Mian-Lue ophiolitic melange in the Qinling Mountains, central China were analyzed to provide insights into the subduction processes during the Late Paleozoic along the margins of the paleo-Tethyan ocean. All igneous rocks from the SCZ block show characteristics typical of arc volcanic rocks such as depletion in high field-strength elements (HFSE) and enrichment in large-ion-lithophile elements (LILE) relative to normal mid-ocean ridge basalts (N-MORB). Included among these arc rocks are high-Mg andesites (HMAs) and an adakitic andesite. The adakitic andesite has a steep REE pattern, low Y and Yb, and high La/Yb values, which is similar to those of typical adakites derived by partial melting of subducted basaltic crust. The HMAs from the SCZ block also have adakitic affinities except that they have lower La/Yb (∼10) and Al₂O₃ (<15 wt.%). Both the adakitic andesite and HMAs have higher MgO, Ni, and Cr contents than the normal andesites and basalts. The age-corrected Nd-Pb isotopic compositions of the HMAs and adakitic andesite show an enriched isotopic signature relative to the MORB-type rocks in the Mianlue area, suggesting that the former probably contain components from sediments or continental crust materials. The data reveal that the adakitic andesite and HMAs in the SCZ block were most probably produced by partial melting of an eclogitic oceanic crust and/or subducted sediments, followed by interaction of the melt with the overlying mantle wedge, and finally by a possible contamination of the melt by the crustal materials. Our result infers that seafloor spreading was active in the paleo-Tethyan ocean, and an ancient island arc system was present along the proto-Qinling area in the Late Paleozoic. The paleo-Tethys ocean separated the South China and North China blocks in Late Paleozoic. The final integration between above two blocks is suggested to have occurred in the Triassic.

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Nitrogen contents and stable carbon isotope ratios of Zelkova serrata leaves collected from roadside trees in Toyama City, Japan were measured in order to judge the stress due to water availability and nutrient efficiency. Furthermore, the source of urban atmospheric CO₂ was examined from the isotopic discrimination between Zelkova serrata leaves and CO₂ in the ambient air based on the correlation between carbon isotope ratio and content of CO₂, since there was no stress associated with the roadside trees. The carbon isotope ratio of roadside tree leaves decreases with increasing traffic. This suggests that the atmospheric CO₂ in urban street is contaminated by exhaust gases of car.

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The lanthanoids (Ln) and yttrium (Y) in rock standard samples issued from the Geological Survey of Japan (GSJ) have been determined by inductively coupled plasma-mass spectrometry (ICP-MS). Sample solutions of two igneous rocks, JGb2 and JR3, with no certified values for Ln and Y were prepared using acid digestion technique, and the Ln and Y were separated from other constituents by a cation-exchange column pretreatment. Corrections for polyatomic interference ions were made for the precise and accurate determination of Ln and Y. The analytical results for Ln and Y in JGb2 obtained by the proposed method were in good agreement with literature values, except for La (22%), obtained by other ICP-MS coupled with cation-exchange pretreatment. The discrepancy of La abundance was mainly due to the different total blank level.

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