Purine and pyrimidine are important chemical components of organisms. These are thought to play an important role on marine ecosystem and organic geochemistry. Therefore, cleanup procedures were developed for the determination of these bases in seawater and pore water. The separation with molecular weight and determination methods of purine and pyrimidine bases were developed by dialysis and HPLC, respectively. Seawater and pore water samples were collected from Harima-Nada, the Seto Inland Sea, Japan. The total dissolved purine and pyrimidine concentrations were 0.44-1.05 μgl^-1 in seawater and 1.63 μgl^^-1 in pore water, respectively. Dissolved-free bases were found abundantly (≅90%) in seawater samples. On the other hand, high- molecular weight fraction (HMWF ≧ 10,000M.W.) bases accounted for 73% of the total dissolved bases in pore water. Uracil is a predominant base in both seawater and pore water. The "apparent production rate" of dissolved free nucleic acid bases was estimated with vertical diffusion coefficient of seawater, to be 0.06 μgl ^-1h^-1.

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A Japanese cypress (Kiso hinoki) grown in Gifu prefecture, Central Japan and a Shorea spruce in Sabah, Malaysia were analyzed for the ¹⁴C concentrations of annual tree rings (1945-1983). Each of annual rings (1958-1966) for the hinoki was divided radially into 3 or 4 consecutive sections. The ¹⁴C concentrations, Δ¹⁴C, of the sections were measured with a Tandetron accelerator mass spectrometer and compared with those of atmospheric CO₂. The good agreement was found between them; this suggested evidently that the Δ¹⁴C values of tree rings could be used to estimate the Δ¹⁴C values of atmospheric CO₂ in the past. Variations in Δ¹⁴C of annual tree rings (1945-1983 ) for the hinoki were found to be closely related with the history of executing the nuclear weapon tests in the atmosphere, by considering that the residence time was about 2 years for transferr-ing CO₂ from stratosphere to troposphere. By using the variation pattern of Δ¹⁴C common to most of trees, the average growth rate of the Shorea spruce (ca. 90cm in trunk diameter), having no growth ring, was estimated to be 5.5mm/yr. A latitude dependence of the Δ¹⁴C variations was found for annual rings (1963-1970) of trees grown in the northern troposphere (6°N-42°N). This phenomenon seemed to be closely related with the mechanism of global mixing for bomb-produced ¹⁴CO₂ in the atmosphere.

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Oxygen and hydrogen isotope compositions (δ¹⁸O and δD) of natural waters can provide useful meteorological and hydrological information. In the present study, oxygen and hydrogen isotope compositions of snow samples from Mt. NAMUNANI (7,694m) and river water samples in Tibetan Plateau were analyzed to deduce sources of the water supplied to Tibetan Plateau. The following conclusions were obtained from isotopic result and d-excess parameter (d=δD-8•δ¹⁸O) which is useful as an index of the source of water vapor mass. 1) In Tibetan Plateau, oxygen and hydrogen isotope compositions of river waters depend on the altitude and on the extent of contribution to surface waters of different water vapor masses (whose sources are different such as Indian Ocean in the monsoon season, the Western areas such as the Mediterranean Sea in the premonsoon, and so on). 2) The d-excess parameters of river waters became larger and δ¹⁸O and δD values heavier with increasing latitude. This fact indicates that the contribution to surface waters of monsoon water vapor mass (smaller d value and lighter δ¹⁸O and δD values) from Indian Ocean becomes smaller with increasing latitude.

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The heavy metal contents of Quaternary "pure" limestones with little or no accessory minerals occurring in Okinawa Island are fairly small, being roughly estimated as Mn : n ppm, Zn : ca. 1 ppm, Ni, Cu : O.n ppm, Pb : <O.n ppm, and Cd : ca. 0.1ppm, respectively. Positive correlations observed between the concentrations of some trace metals and that of Fe strongly suggest that these metals have behaved together with Fe during the formation, diagenesis, and weathering processes of "impure" carbonate rocks having a large amount of the acid-insoluble residue. The main factor governing the incorporation of these metals into carbonate rocks from sea water may probably be the adsorption mechanism by colloidal hydrous Fe (III) oxides. These metals might have been successively migrated to pyrite from the hydrous Fe(III) oxides during pyritization occurred in reducing environments, and then finally incorporated into Fe(III) oxides such as goethite, which was presumably formed from pyrite by weathering under subaerial oxidizing conditions. No positive relationship was observed between the Cd and Fe contents, indicating that Cd may differ in its behavior from the above metal ions. Similary, Mn content is not proportional to that of Fe. A significant amount of the element, however, may be found in the 1M HCl-soluble fraction, that is, the lattice of carbonate minerals.

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The Kuzuu carbonate rocks are divided into three major units, the Upper Limestone, Middle Dolostone, and Lower Limestone Members. Ni, Cu, Zn, and Cd contents of twenty-four limestone and twenty-six dolostone samples from these members were determined by atomic absorption spectrophotometry coupled with APDC - MIBK extraction to clarify the geochemical behavior of these metal ions during the formation and diagenesis of Permian carbonate rocks. As far as the limestones having a relatively small amount (< 1 wt. %) of impurities are concerned, both Quaternary and Permian limestones contain Ni and Cu in the same order of magnitude, but Zn and Cd tend to accumulate in the latter. The abundance of these metals in the Permian limestone is roughly eastimated as Ni and Cu; ca. 1 ppm, Zn; n ppm, and Cd; O.n ppm, respectively. The average ratios of 1 M acetic acid-soluble metal content to the total are fairly high (> 60%) as to Upper Limestone and the Middle Dolostone samples whose impurities are less than 1 wt. %. This fact suggests that a significant amount of these metals is sieved in the lattice sites of low Mg-calcite and dolomite rather than impurities. On the other hand, these metals in the Lower Limestone samples may mainly be contained in pyrite which has probably been formed under reducing envi ronments during the formation of these limestones. No significant increase can be seen in these metal contents of the Middle Dolostone samples due to dolomitizing solutions, though 1 M acetic acid-soluble Zn and Ni are slightly higher in these rocks as compared with those of the Upper Lime stone samples.

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