During the five‐year period (April 1981 ‐ March 1986), a series of fifteen rock reference samples, “Igneous rock series”, has been prepared by the Geological Survey of Japan (GSJ). Based on the data available (published and communicated), consensus values for major, minor and trace elements have been derived; these values are presented for this second series of samples as well as for the first series of two samples, Granodiorite JG‐1 and Basalt JB‐1.

No abstract

Abstract--The hot spring water discharging from a flank of an active volcano is precipitating unique monomineralic manganese deposits over volcanic terrain. The major and trace element chemistry, XRD mineralogy, DTA, and SEM observations indicate that the deposits consist of 10/~ phyllomanganate (buserite) accommodating inter-layer Ca and Mg with negligible amounts of detrital minerals. Other metallic elements can be accommodated by buserite, but concentrations are negligible ranging less than 10 ppm to 500 ppm. Abundance and pattern of REE (less than 100 ppm in total) are similar to those from hydrothermal manganese deposits. The buserite is enriched in Ca and Mg but depleted in Na in comparison with those in the spring water. The distribution coefficients for Ca, Mg and Na between the buserite and the host water were calculated assuming an ion-exchange equilibrium in the Yuno-Taki Fails, which proved applicable to other manganese deposits from surficial environments on land and oceans.

The formation process of hydrous manganese oxide deposit can hardly be demonstrated in natural environments, namely, hot and cold springs and deep-sea hydrothermal vents. We discovered a unique phenomenum that hydrous manganese oxide is now actively depositing from the hot spring water at the Yuno-taki Falls, Hokkaido, Japan. The chemical and the biological factors that potentially control the actual manganese deposition in the natural environment were examined.Pure manganese oxide deposit (1.1 ton/year calculated as Mn02) is currently being formed from weakly acidic hot spring water by the mediation of microbial consortium consisting of manganese-oxidizing bacteria and filamentous algae. A comparison of the mineral deposition at this location with other terrestrial and oceanic deposits suggests that they were formed in a similar manner.

Analytical data for fourteen rare‐earth elements, scandium, yttrium, zirconium and hafnium, received by May 1992, have been compiled on twenty‐six GSJ (Geological Survey of Japan) reference samples. Seventeen of them are ‘Igneous rock series’ and nine are “Sedimentary rock series”. The reported data including personal communication were evaluated under the consideration on analytical methods and geochemical evidences. No significant difference has been observed between the values obtained by the different analytical methods. Based on the selected available data, 1992 compilation values were tabulated.