The Babame-Kurogezawa districts in Akita are underlain by the metamorphosed Cretaceous granitic rocks at the basement. The Neogene Tertiary system, which overlies the basement, consists of the Kitanomata, Hikarizawa and Onnagawa formations in ascending order. The Kitanomata formation is of terrestrial nature as evidenced by the occurrence of welded tuff. The lower part of the Hikarizawa formation consists of sandstone-mudstone member and volcanic conglomerate member in ascending order. Plant fossils occur in the former and marine fossils such as calcareous nannofossils occur in the latter. The beginning of the marine transgression is estimated to have occurred later than 17.95 Ma. The middle to upper parts of the Hikarizawa formation are characterized by bimodal submarine volcanism with mudstone, being assigned to the Nishikurosawa stage. The Onnagawa formation consists of hard mudstone and basaltic pyroclastic rocks. The Babame and Hikarizawa kuroko deposits are hosted at the middle part of dacitic member and the host horizon is different from that of the Hokuroku district where kuroko deposits are hosted within upper part of the dacitic lavas of the Nishikurosawa stage. However, mineralization periods are thought to be not so different between them. Meanwhile, auriferous quartz veins are distributed at the Haginari deposit in the Babame district and the adjacent Kurogezawa district. K-Ar ages of their altered host rocks indicate 11.4±0.3Ma for the former and 53.5±1.3Ma for the latter. The former age is normal for the mineralization period of the surrounding area, but the latter age corresponds to the period of the basement metamorphism.

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In order to understand behavior of CO₂ in underground associated with CO₂ sequestration in aquifer, we need to investigate the kinetics involved in solubility and mineral trapping. Here we conduct basic dissolution experiments using 3 powdered sedimentary rock samples collected from the Boso Peninsula, Chiba Prefecture in order to calculate dissolution rate constants, k for the 3 main constituent minerals: plagioclase, calcite, and dolomite. The k values for plagioclase calculated using temporal changes in H₄SiO₄ concentrations were within the range of values presented by Sverdrup (1990) or up to roughly 1 order of magnitude larger. We attribute this discrepancy to the difference between geometric and reactional surface area, dissolution of clay minerals in our samples, and increase in dissolution sites due to having powdered the samples. The k values for calcite and dolomite calculated using temporal changes in Ca²⁺ and Mg²⁺concentrations, respectively, turned out to be roughly 1 order of magnitude smaller than the values presented by Bidoglio and Stumm (1994) because of our inability to exclude contributions by ion exchange reactions to overall Ca²⁺ and Mg²⁺ concentrations. When temporal changes in HCO₃^- concentrations were used instead, the k values roughly matched those of Bidoglio and Stumm (1994) for both calcite and dolomite.

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Reconnaissance chemical study was made on the lead-zinc ores from Paleozoic sedimentary units of the northern Vietnam, which belongs to the South China block. Special attention was paid to the In-content, because of large producers of Dulong and Dachang mines located in the Chinese side. The lead-zinc ores have sporadic high In-contents, being the highest in the Nabod ores (In_sp=10 - 2603 ppm, average=688 ppm In, n=7). Zn concentrates of the Dien mine are 67 ppm In, which could be recoverable with the recent prices. From the ore textures and ore setting in the sedimentary host rocks, and Cd_sp contents, no typical Mississippi Valley-type deposits are observed in these lead-zinc ore deposits in the northern Vietnam.

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Chemistry of the Permo-Triassic and Cretaceous-Tertiary granitoids in the Malay Peninsula region was reviewed putting an emphasis on the Y and HREE contents. The major Permo-Triassic granitoids are mainly felsic I-type ilmenite series. Some magnetite-bearing granitoids, like those of the East Belt of Malaysia may belong to an intermediate series. The Cretaceous-Tertiary granitoids look similar but become I-type magnetite series toward the Tertiary igneous rocks along the Central Valley Belt of Myanmar where adakitic granitoids occur in a small area. HREE, whose contents are very much correlated with Y content, are concentrated in two modes of occurrence: one with coarse-grained biotite granites observed, e.g, in the Samui Island of the southern Thailand and Dingdings pluton of western Malaysia, while the other is Sn-W mineralized fine-grained leucogranitic stocks at Hermingyi, Lower Myanmar, and several places including Yod Nam mine of the Central Belt.

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