Impregnation sulphur deposits and solfataric emanations of many volcanoes in Japan have been studied and based on that research the following hypothesis for the genesis of the impregnation sulphur deposits is proposed:
(1) The deposits tend to accumulate in geological structures such as alternating lava flows and pyroclastic rocks.
(2) Near the surface, iron sulphide and free sulphur are oxidized by oxygen in the atmosphere, thereby producing H₂SO₄ and Fe₂(SO₄)₃.
(3) Meteoric water dissolves the H₂SO₄, Fe₂(SO₄)₃, and atmospheric oxygen and flows into the ground and down through permeable rocks as tuff-breccia, agglomerate etc. to and along the upper surface of inclined impermeable stratum such as shaly tuff and lava flow etc.
(4) These rocks are heated by some heat source which exists in the depths of the volcano. The descending water reaching upon the rocks is soon heated and a part of it evaporated into steam.
(5) The mixed vapour of the steam and volcanic gas containing H₂S, CO₂, HCl etc. which is expelled from the magma, flows up vigorously in to the upper parts of the permeable rocks to and along the lower surface of an upper impermeable stratum, where the remains of the solution becomes mist and is carried away by the mixed vapour.
(6) H₂SO₄, Fe₂(SO₄)₃ and oxygen dissolved in the mist react to H₂S to form free sulphur as follows,
3H₂S+H₂SO₄=4H₂O+4S
2H₂S+O₂=2H₂O+2S
4H₂S+Fe₂(SO₄)₃=2FeSO₄+4H₂O+5S
(7) The mist is highly acid and it attacks the surrounding rocks and has them porous by dissolving the AL₂O₃, FeO, Fe₂O₃, MgO, CaO, K₂O, . Na₂O etc.
(8) The free sulphur fills up the interspaces and the silica of the original rock minerals remains in place as opal. In this manner the sulphur rich ore is made.
(9) The temperature at the time of sulphur deposition is presumed to be from about 120°to 150°C, and the pressure about 2 to 4 atm..
(10) Under the upper impermeable stratum, the acidity of the mist is less than that of the mist near the lower impermeable one. Most iron sulphide ore is made near the upper stratum because the enviroment at that place is more suitable for the precipitation of iron sulphide.
(11) In the rocks adjacent to the deposit and near the upper surface of the under impermeable stratum, the temperature is lower than that of the middle part of the deposit and opalization is predominant.
(12) The solfataric gas, containing steam, H₂S, FeSO₄, some free sulphur, and mist of hydrothermal solution ascends to the surface and issues from the solfatara.
(13) The atomospheric oxygen oxidizes the solfataric gas again and the cycle is repeated.

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The region surveyed is mainly composed of various kinds of pyroclastics of middle Miocene to lower Pliocene age. It is crowded by a large number of gold, silver, copper, lead, zinc and ironsulphide ore deposits. The deposits occur in strata older than the lower part of upper Miocene, and are thought to have been formed at the last of Miocene epoch. They are chiefly of vein type (more than 11 mines), but a few network-impregnation deposits are also present (2mines).
The deposits are classified into three groups on a basis of the kind of ore: (1) gold deposit, (2) base metal sulphide (Zakko) deposit characterized by mixture of sphalerite, galena, chalcopyrite and pyrite, and (3) copper, deposit rich in iron-sulphide characterized by scarcity or absence of native gold, sphalerite and galena. These three groups fall within three parallel layers or zones striking NW-SE and dipping gently to SW. The ores have a distinct zonal distribution. Gold deposits are in the shallower zone, base metal sulphide deposits in the intermediate zone, and copper deposits in the deeper zone. The succession of ore minerals as related to zoning and the physicochemical relationships are discussed.
The system of the vein fissures shows the dynamic character of these deposits. Analysis of the fissure patterns suggests that the region suffered from a horizontal couple directed WNWESE as regional fissuring force, when the earth's surface may have played important rôle as free surface in determining the direction of fissures.
Behavior of minor elements in the several sulphides is described briefly.
In conclusion, the deposits in this region are thought to be "subvulkanisch" epithermal.

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A new boring in Karatsu Coal Field No.2 revealed an unconformity between the Kishima beds and Yoshinotani beds (Kawago beds). The remarkable crustal movements that faulted and folded the Yoshinotani beds (kawago beds) prior to the deposition of the Kishima beds are correlative to the Savian phase. The movements are called the pre-Kishima phase.

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A limonitic substance replacing a kind of moss was found in the floor of astream issuing from a ferruginous spring (pH=2.9) at the Horaitakamatsu mine, Akita Prefecture. The substance is very similar to "limonite" in its external appearance, but the chemical analysis (Table 4) and differential thermal analysis (Fig. 1) show that it is not hydrous ferric oxide but basic ferric sulphat. Its occurrence, microscopic features, chemical analysis, differential thermal analysis, and X-ray diffraction analysis are considered in this paper.

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Many reports. have been published regarding the use of staining tests for clay minerals. The writer discussed the applicability of staining tests for the identification of the clay minerals using the reagents, such as p-aminophenol, p-phenylendiamine, p-aminodimethylaniline, o-tolidine, and o-dianisidine, and he informed that the better results were obtained when one of these reagehts was used with another.

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