Tourmaline-bearing hydrothermal veins and metamorphic tourmalines occur in the Kamihirose Formation, circum-Hida terrane. The Kamihirose Formation was intruded by the Funatsu granitic rocks and underwent the contact metamorphism. Two types of tourmaline-bearing hydrothermal veins were distinguished: (1) tourmaline vein, which consists mostly of tourmaline with quartz and minor apatite; (2) potassium feldspar vein, which consists mostly of orthoclase with quartz, plagioclase and acicular tourmaline.
     Metamorphic tourmalines are found in sandstone and tonalite porphyry and tuffaceous sandstone clast of conglomerate. There are three types of sandstones that yield metamorphic tourmalines: black, white and acidic tuffaceous sandstones. In the black sandstone, the metamorphic tourmalines occur in shale fragments and occur as overgrowth on detrital tourmalines, whereas, in the white sandstone, those occur in acidic tuff fragments. In the acidic tuffaceous sandstone, metamorphic tourmalines occur in the tuffaceous matrix.
     The electron-microprobe analyses of tourmalines revealed the facts as follows ;
     (1) The tourmalines from the Kamihirose Formation are members of schorl-dravite solid solutions.
     (2) The tourmalines in the hydrothermal veins probably contain Fe³⁺, which substitutes for Al.
     (3) The metamorphic tourmalines have a wide compositional range reflecting various chemical features of host rocks.

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Experimental techniques to minimize loss of iron and sodium from sample materials in experiment using one atmosphere gas mixing furnace are proposed. Melting experiments for basaltic synthetic materials and natural basalts and andesites were carried out at 1150∼1250°C and oxygen fugacities from air to ΔNNO=−5.0. Based on the results of present experiments and previous works, the folowing empirical relationships were derived. Relationship between iron content of platinum loop (X_Fe^{FePt alloy}) and FeO contenlt in silicate liquid (X_{Total FeO}^Liquid) was described by

      X_Fe^{FePt alloy}(wt%)=(1.782-0.0908X_{Total FeO}^Liquid(wt%))logf_O2+0.2574logf_O2²        (1).

Correlation among Na₂O loss from liquid (Y) and oxygen fugacity, run duration (t), mass of liquid (W), temperature (T) and chemical composition was described by

      ln[−ln(1−Y(%)/100)]=18.66+2.145×(FeO+MnO+MgO+CaO)/SiO₂(mole ratio) −0.225ln f_O2−416800/RT(K)−1/3×lnW(mg)+lnt(min)        (2).

     Melting experiments using iron-plated platinum loop whose iron content was calculated from equation (1) and setting Na₂SiO₃ liquid below the sample were also performed. Loss of FeO and Na₂O from sample materials could be reduced considerably by the iron-plated platinum loop and Na₂SiO₃ liquid. In experiments of iron partitioning in alkaline rich system at reducing oxygen fugacity, continuous change of bulk chemical composition and disequilibrium can be minimized by these techniques.

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Basaltic rocks from Daikonjima, a young shield volcano in Nakaumi Lagoon (eastern Shimane Prefecture), have been dated and analysed for a range of whole-rock major, trace element, and isotope data. K/Ar age data indicate a Quaternary eruption age of circa 200 000 years. Chemical data for a range of stratigraphically controlled samples show that they are all fractionated relative to basaltic primary liquids (100 Mg/(Mg+Fe)∼56, Ni 101-160 ppm, Cr 110-226 ppm). In terms of Sr and Nd isotopes, they represent a homogenous reservoir close to bulk earth values. The earliest magma results from a lower degree of partial melting than later magma batches, and variations in chemistry between younger lava flows can probably be attributed to small differences in modal mineralogy, although the possibility of limited crustal contamination cannot be excluded.

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