Sulfur, boron, and lithium isotope ratios were studied in view of economic geology. Stadard samples of sulfur, boron, and lithium isotopes were also discussed. In the genetical study of the ore deposit (Sudbury district Canada), the sulfur isotope ratio (S^32/34) gave valuable hints. Sulfide minerals of different chemical compositions and physical forms in the Yanahara ore deposits presented an nteresiting result. The sulfur isotope ratios of closely associated minerals showed an appreciable fractionation. This suggests that some isotopic fractionation would be expected during thermal decomposition of pyrite. The sulfur isotope ratios may serve as useful indicator in the geochemical prospecting method at Yanahara, Nonowaki, Opemiska, and Helen mines. Possibility of age determination by Li^7/6 ratio in uranium ore deposit was mentioned, too.

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In the vicinity of the Nissho Mine, Yamagata prefecture, the stock or apophysis, about 3km im diametre from north to south is found in the strata composed of pyroclastic rocks, normal sediments and dolerites as sheets or dykes, of middle Miocene in age. The emplacement of the stock results in forming a dome structuse of the strata.
The intrusive body has variable facies as follows; quartz diorite and granodiorits in the core and, quartz porphyry, rhyolite 1 (lithoiditic) and rhyolite 2 (nevaditic) in the margin. Rhyolite 1 or rhyolite 2 is a kind of the chilled margin, These variations are transitional. Namely, the stock varies from holocrystalline to hyaline in texture and increases the acidity to the margine. Another hyaline felsitic rock, rhyolite 3, intrudes the stock as if surrounding the stock from north to east. The author calls them "Tertiary eranitic rocks".
Silicification of all country rocks and partial thermal alteration of dolerite are recognized as the contact effects of the stock. Hornfels alered from dolerite has the recrystallized minerals of anthophyllite, cordierite and biotite at the very contact, but retains toe ophitic texture. of dolerite.
Fissure patterns are radial and concentric to the dome structure, caused by local upheaval of the strata. The intruding directions of minor dykes of rhyolite 1, 2, 3, and quartz porphyry are controled by these fissure patterns.

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Mode of intrusion of an igneous rock into coal seams and some noticeable aspects of thermal metamorphism of the coal at Takashima colliery are summarized in this paper. The igneous rock mentioned above consists only of one rock type, which has been difined as a tholeiitic basalt on account of itschemical and mineralogical compositions. This rock has changed generally to a saponitecarbonate rock due to autoalteration.
The igneous rock intrudes the coal seams as a sill. The intrusions took place evidently after the main tectonic movements which formed the major fault system. The feeder of the basaltic magma should be a system, which is supposed to occupy a tension crack system formed in the Takashima dome. The movement of the sill intrusion has been controled by the pre-existing fault system, by the load of the roof sediments, and also by the dip of the seam.
Zones of differentially metamorphosed coal are distinguished from the contact between the coal and the basaltic sill. A few examples of such zonal arrangement are interpreted in this paper, thoughthe chemical and physical details of the metamorphosed coals will be published in other papers.

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Mineralization of the ore deposits of the Chin-qua-shih Mine is classified into three stages as follows :
Stage Mineralization Ore and gengue minerals
[I] Alteration of wall rock Chlorite, quartz, pyrite, alunite, argillite
[II] Precipitation of Cu Minerals Enargite, (pyrite), (quartz)
[III] Precipitation of Au and Ag Minerals Limonite with Au, Ag, (barite), (quartz)
The above classification was based on the differences in the mineral paragenesis, the Au-Ag ratio and the distribution of minor.
Authors conclude that limonite of the third stage accompanying Au and Ag minerals is not an oxidation product from pyrite of the second stage, but is a direct precpitate from a hydrothermal solution of the third stage.

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