Normalised major and trace element data of manganese ores from Nishikhal are processed by using R-mode factor analysis of correlation matrix. Twenty major and trace elemental variables are expressed in terms of 3 common (rotated) factors to understand the mineralogical occurrences and the processes of formation of the manganese deposit. Varimax factor scores are used to classify in a finer detail the manganese ore types.

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The genesis of melanterite (FeSO₄·7H₂O) from an abandoned iron mine was investigated. The ferruginous and/or sulfate mineral zones observed on a wall at the alit was as follows: 1) on the upper part of the wall, the iron sulfide minerals zone with melanterite, 2) the goethite zone overlying skarn minerals, and 3) the goethite and gypsum zone with a small amount of malachite overlying limestone. The pH of the seepage water increases from zone 1) to zone 3). The distribution of ferruginous minerals was controlled mainly by the pH of the seepage water and partly by the rate of the water supplied.
     In the iron sulfide minerals zone, sulfate and Fe(II) ions are derived from the decomposition of the sulfide minerals, and dissolved to acidic water. Melanterite precipitated in place from the acidic water by evaporation. At the lower part of the wall, the pH of seepage water increased by the reaction of the acidic water with Ca bearing minerals, hence the dissolved Fe(II) ion was oxidized rapidly and precipitated as goethite. The rate of oxidation from Fe(II) to Fe(III) also depended on the residence time of the seepage water, and, under acidic conditions, a thin layer of goethite deposited in points where insufficient seepage water was supplied from the upper zone. From the resultant iron free water, gypsum precipitated partly at the bottom of the wall by evaporation.

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The Habu granodiorite mass (Habu mass) occurs in the western part of the Sanyo belt, Chugoku district, Southwest Japan. It is composed of the following rock types; porphyritic hornblende tonalite to granodiorite (marginal facies) and fine-to medium-grained biotite granite (main facies). This mass forms a normally zoned pluton with a compositional variation from the mafic margin to the felsic center.
   Six granitic rocks from the Habu mass give a Rb-Sr whole rock isochron age of 124.2±10.8 Ma with an initial ratio (SrI) of 0.70597±0.00024, which is the oldest age among granitic rocks from Sanyo belt. The SrI of the Habu mass (0.7060) is similar to the granitic rocks from the western part of Sanyo belt, suggesting that the activity of granitic magma in Sanyo belt had started at least 124 Ma.

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