The pyrophyllite deposits in the Hokushin district, Nagano Prefecture, can be divided into the next two groups. The first group deposits are distributed in the eastern area of the Chikuma river. Since they occur in or adjacent to diorite-porphyrite of the Miocene age, it is probable that they were formed by hydrothermal alteration closely related with the intrusion of the porphyrite. Usually, the deposits that occur in the porphyrite are chimney-like in shape and rather small in scale. Pyrophyllite, zunyite, diaspore, colundum, nacrite, dickite, etc. were found in the deposits of this group. But exceptionally, the pyrophyllite deposit of the Shinyo mine occurs in the tuffaceous sediments intruded by porphyrite branch dikes. And it was largely developed replacing mainly the permeable beds of the sediments. Pyrophyllite, sericite, kaolinite and diaspore were found in this deposit.
The second group deposits are distributed in the western area of the same river. They occur in volcanic rocks and pyroclastics of the Miocene age and occasionally in basaltic andesite lava of post-Miocene age. Because of the extensive distribution of altered rocks, it is reasonably considered that they were formed by exhalative hydrothermal alteration relating with areal volcanic activity. Some deposits of this group occur being accompanied by remarkably silicified rocks. Main constituent minerals of these deposits are pyrophyllite, quartz, diaspore, sericite and alunite.
As summarized in the table, there are distinct differences in geologic occurrence and mineral association between these two groups. Especially, the zonal arrangement from the pyrophyllitized zone to the weakly altered zone through the intermediate one is characteristic of the first group deposits, which belong to the higher temperature hydrothermal type. On the other hand, some of the second group deposits that belong to the exhalative hydrothermal type show the zonal arrangement from the silicified zone to the weakly altered zone through the pyrophyllitized one. These facts suggest that there were differences in chemical property of hydrothermal solution which took part in the formation of pyrophyllite deposits.

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Microanalysis has been conducted to find out the distribution of minor elements in pyrite and chalcopyrite in the ores and host rocks from the Shakanai Mine which is one of the typical poly-metal ore deposits called in Japan by the name of Black Ore Deposits. It is composed of dense aggregates mostly of sulfide minerals. To separate pyrite and chalcopyrite from ores and host rocks is very difficult and laborious, but by using heavy liquids, isodynamic separators, elutriating tubes and so on repeatedly, pyrite and chalcopyrite can be purified to a very high degree.
In this study, first, 23 samples of pyrite and 17 samples of chalcopyrite were separated trom ores and host rocks. Next, the qualitative analyses of these samples were made by Jarrel-Ash Evert-type 3.4m grating spectrograph (JACO). As a result 22 elements from pyrite, and 18 elements from chalcopyrite have been detected. These data were studied in reference to the localities of the samples, and the following conclusions have been drawn.
(1) Most of minor elements in pyrite and chalcopyrite show clear differences between ores and host rocks, that is, Ag, As, Ba, Bi, Cd, Cu, Ge, In, Mn, Sb, So, and Zn content in pyrite and As, Ba, Bi, Cd, Cr, Ga, Ge, Mn, Pb, Sb, Sn, and Ti content in chalcopyrite indicate higher values in ores and lower values in host rocks. On the contrary, Co, Ni, and Ti content in pyrite are concentrated in host rocks.
(2) As a result of field survey, the selected ore body is divided into seven more little unit-ore-bodies. The samples of pyrite and chalcopyrite from each unit-ore-body include various different quantities with respect to a few minor elements like Ba, Bi, In, and Sn. The other elements were not recognized a distinct difference between them.
(3) According to the findings of Kajiwara (1970), some veins are considered as feeder channels through which the ore-forming solution was supplied. So pyrite and chalcopyrite-rich part, sphalerite and galena-rich part and clay-rich part were selected from a typical vein located under the ore body. The contents of minor elements in those three parts were then compared with those in the ore body. The comparison shows that the behavior of most minor element contents except Bi, resembles that in ore body. This fact probably suggests that the vein has been a feeder channel, and this presumption agrees with the data obtained by field investigations.
(4) The distributions of minor elements in pyrite and chalcopyrite are classified into two groups-the regular group and the irregular group. The regular group to which many elements belong, shows such distinct tendencies as in almost all of pyrite-chalcopyrite pairs, and As, B, Ba, Cd, Co, Mn and Ni element are always enriched in pyrite and Ca, Cr, Ga, Ge, In, Sb and Zn element are enriched in chalcopyrite. This fact may be explained by the differences in the temperatures or other conditions of the ore-formation. The other group including six elements such as Ag, Al, Bi, Mg, Pb and Sn shows irregular variations in the amount of above-mentioned elements, for in some cases they are concentrated in pyrite and in other cases they are found concentrated in chalcopyrite.

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The limestone and dolomite deposit at Kuzuu-machi, Tochigi prefecture is very famous as one of those largest deposits in Japan. It is Permian in age and consists of the Nabeyama formation, which is divided into the lower limestone, the middle dolostone and the upper limestone. The Nabe-yama formation overlies conformably the Aizawa formation, which consists of sandstone, alternation of sandstone and shale, and schalstein in ascending order, and is covered unconformably by the Ado-yama formation, which consists of mainly chert and shale.
Because of minor phosphor contents and small grain sizes of the phosphor-bearing mineral, it has long been impossible to confirm the mode of occurrences of phosphor and the phosphor mineral.
It is concluded, however, from the results of X-ray powder diffraction, chemical analyses and electron microscopic analyses, that the phosphor mineral occurs as cryptocrystalline fluor-apatite.
The mode of occurrences of apatite is classified as follows:
1) Apatite is disseminated within the definite horizons in limestone and dolostone.
2) Apatite forms a lamina intercalated in the alternation zone of shale and calcitic dolostone in the middle dolostone.
3) Apatite occurs in the lowermost part of the Adoyama formation as gravels with maximum dimensions of 10cm×5cm×3cm in the calcareous breccia and as tiny grains with diameter of0.2-0.5cm in the calcarenite.
4) Apatite occurs in the fillings of cracks in limestone and dolostone as grains with diameter of0.5-1.5cm.
5) Apatite occurs in the fault clay in limestone and dolostone as clay fraction.
It is considered that apatite in the first two cases is syngenetic with limestone and dolostone deposits and apatite in the other three cases is derived from the syngenetic apatite.

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The genesis of the bedded manganese deposits has been discussed by many geologists with the different view-points. The writer intends to know the change of Mn and Fe contents in the wall rocks of this type of ore deposits and its relation with the genesis.
The study was carried out at the Misago ore body of the Noda-Tamagawa manganese Mine, Iwate Prefecture. Semi-quantitative analyses of Mn and Fe contents in the wall rocks were made by the X-ray fluorescence method. The two elements, Mn and Fe, are variously contained in the wall rocks and the difference between the concentration of these two elements in the hanging wall and foot wall is considered to be related to the different environments of sedimentation of the wall rocks. Also it is found a Mn-poor zone existed in the wall rocks near the ore body.
The Mn and Fe contents of the wall rocks as an indicator for ore prospecting are only effective within the distance of a few meters from ore bodies.

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With water pressures of 300 atm and 1, 000 atm, vesuvianite is synthesized from glass, the composition of which is 10 CaO⋅2 MgO⋅2 AL₂O₃⋅9 SiO₂, between 400°C and 600°C. At lower temperatures the assemblage, grossularite-diopside-2 CaO⋅Si0₂nH₂O, is stable, while at higher temperatures the assemblage, melilite-wollastonite-monticellite, becomes stable.
Vesuvianite occurs rather rarely in skarn. It is found in the high temperature-zone of zoned skarn.
This experimental result and the occurrence of vesuvianite may indicate that the pyrometasomatic ore deposits were generally formed below 400°C.
Units cell dimensions of synthesized vesuvianite and of grossularite decrease with temperature. Cell dimensions of grossularite synthesized in this work are lager than those of grossularite synthesized from the composition of 3 CaO⋅AL₂O₃⋅3 SiO₂ and are smaller than those of grossularite from 3 CaO⋅AL₂O₃ 2 SiO₂.

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