The Fossa Magna Disturbance is the one of the greatest orogenic movements in Japan. It has happened at those provinces of Izu, Kai, Shinano and a part of Echigo in Central Honshu; but its influences ex-tend to the Boso and Kwanto resions toward the east, and the Mino-Hida Plateau, Kinki district and eastern part of Setouchi toward the west, while they do to Kaga, Noto, Ettchu and farther the Yamato Bank, a submarine ridge in the middle of the Japan Sea toward the north. In regard to the cause of the disturbance, once the writer has stated in another paper:-“ the tapering apex of the Shichito batholith underlying the Shichito submarine ridges first might have applied itself obliquely to the Outer Zone of Southwestern Japan running to west-east, and then by the lateral thrust from the south it has been pushed into the Mesozoic series occupying the outermost of those series of the Outer Zone. The batholith pushed into the Mesozoic series might have an interval of 130km., which is represented by the length of the north-south fault between the bartholith and the Misaka series (Nishi-Yatsushiro group), whose existence might be suspected along the submarine valley of Suruga Bay stretching from the mouth of the Fuji River to the eastern end of the Nankai Trough.”
The directrix of the batholith is north north west- south south east; and with the increase of pressure from the south, all the series of the Outer Zone have been bent toward north north west and have delineated an asymmetric arc represented by the Toyohashi-Suwa-Maruko-Chichibu-Daitozaki. Such an asymmetric arc which is steep toward west, but gentle toward east, may easily break off along the slide which lies to the left shoulder and just below the apex of the arc as experimentally proved by Hobbs. By the pressure from the south, the arc is broken in the slide and its right wing is displaced along the Transverse Rift which must needs have been made. The Transverse Rift starts first at Itoigawa and along the eastern foot of the Mino-Hida Plateau comes to Nirazaki, whence it passes obliquely southeast through the bottom of Fuji Volcano via the Sagaminada and enters the Shichito Trench. By the 60km. displacement to northwest of the right wing along the Transverse Rift, which is represented by the crossing of the Median Line between Suwa and Omachi, the Echigo Mountan block was wrenched off from the Mino-Hida Plateau; and the waters of Japan Sea found their way into the Pacific through the depressed Fossa Magna region.
On the western side of the Transverse Rift, there lies three parallel mountain ranges, Akaishi, Kiso and Hida. They may be Echelon folds of Dr. Fujiwara, made by the shear of the rift, along which the right wing of the arc is displaced 60km. northwestward.
The Fossa Magna is penetrated by the Fuji volcanic zone, the southward extension of which reaches the Yap Island via the Volcanic Island. Dr. Tsuya has classified the volcanic zone into the Inland Volcanoes and the Marine; according to him, the Andesite of the former is more Alcalic and contains lesser Calcium than the latter.
The depth of the Shichito Trench reaches 9, 000m, and lies parallel to the Shichito submarine ridges running northsouth. The bottom is penetrated by the fault whose plane dips west, an forms a Deep-earth-quake zone in the depth of above 300km. On the way the fault may turn its course and pass the Fossa Magna.
The mountain making, volcanic eruptions and deep trenches are the immediate products of the orogenic faults made by the force coming from the southeast may be noticed in the south region, where the Neodani fault and Yanagase-Kinomoto fault are famous. Their trends are northwest to southeast and the eastern sides usually move to northwest. In the north of the plateau, there are the Yokoyama and Nirehara faults runing eastwest, and granite thrust over the Tetori series from the south, which indicates a force coming from the south.

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The writer investigated the origin of groundwater using its chemical contents of the water from 232 wells and, based on its result, he presumed the geologic structure of Irumagawa alluvial fan, Saitama Prefectuer. By the measurement of the wells, he made Fig. 5-7, from which he considered the hydro-logical conditions of groundwater. He analysed S0₄, '' Cl, ' Fe of groundwater. The results are shown in Fig. 8-11. The influence of human contamination was considered from the value of _??_. The origins of groundwater in this region were classified into three, that is, human contamination water, non-conta-minated water and mixed water. Lastly, discussing the relation between the origins of groundwater and the geologic structure of this region, he classified the unexposed deposits of the fan into gravels, sands and clay deposits as the result of examining of the value of _??_.

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The modern coal mining in the Joban coal field was started on the exposed areas of the coal field near the foot of the Abukuma mountains in 1883. The volume of coal produced has been increased since, and 4.29 million tons of coal, about 8 per cent of the total coal production in Japan, was produced in 1958 (Fig. 3).
Though the number of collieries is 71, the large collieries producing over 300 thousand tons in one year are only 3. The majority of collieries produces under 50 thousand tons in one year. The pattern of the mining activity in the field is roughly shown in Fig. 1.
The results of the study are as follows.
1) The geologic conditions of the coal measures are also responsible for the pattern of the coal mining in the Joban coal field. The writer divided the field into four districts and made a comparative study of the natural conditions for mining-coal reserve, quality of coal and depth of coal series etc.-in each district (Tab. 1).
It reveals that the best natural conditions for mining exist in the northern district of Iwaki and the Taga district, The southern district of Iwaki and the Futaba district are very inferior to the former districts.
2) In consequence, the two centers of the coal production in the Joban coal field are the northern district of Iwaki and the Taga district. These two districts produce about 91 per cent of the total coal production in the field. The collieries producing over 100 thousand tons of coal in one year are all concentrated inn this two districts.
3) In the coal field, especially in the northern district of Iwaki, almost all of the concessions which hold the abundant coal seams are monopolized by the Joban Coal Mining Co. Ltd., the largest coal mining company in the Joban coal field. The company has also increased the output of coal in the Taga district since 1935, and today, the company produces over 50 par cent of the total coal production in the field.
4) The central areas of coal mining-the northern district of Iwaki and the Taga district-were formed in the period 1897-1919 and in this time almost all of the main collieries were opened. From the beginning the Iwaki Coal Mining Co. and Iriyama Coal Mining Co. were the two largest producers. They were merged to be the Joban Coal Mining Co. in 1944.
5) In the area of the abundant coal seams such as the northern district of Iwaki and Taga districts, the centralization of coal production to the large collieries resulted in making the many small collieries subordinate to the large collieries. Because, in these two districts the small collieries are compelled to locate in the small concessions to mine the thin coal seams, and these concessions were already mined out the thick coal seams by the large collieries and were left as the areas which came to the end of mining. Moreover, the areas of the poor coal seams such as the southern district of Iwaki and the Futaba district are where many small collieries are operated. Such conditions are shown in Fig. 5.

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Soviet industry has developed on the basis of Soviet industrial location policy, which considers that every important industry will develop under the use of the resources in the economic regions and at the same time that all the industries will develop so that regional self-surfficiency can be attained in each economic region.
Consequently, the iron and steel industry has developed especially in the areas producing iron ore resources and coking coal resources (the Urals, the Ukraina and Siberia). At the same time, although the steel output is poor, new steel industries supply raw materials to the machinery indusry was establishedd in each economic region. But up to the present, Soviet iron and steel industry has mainly progressed in the Urals and Sourthern Russia (the Ukraina), though the geographic distribution of iron and steel industry is spread wider than that of Pre Soviet days.
It requires further development of the Ukraina and Urals and the exploitation of Siberia, Central Russia (Kursk) and Kazakhstan (Kustanai) in order to produce from 65 to 70 million tons of pig iron and from. 86 to 91 million tons of steel in 1965. Furthermore, in order to make much greater progress, Soviet iron and steel industry has following problems to be solved, that is, the elimination of irrational long distance transportation and cross haul of iron and steel products, the prevention of becoming higher costss in iron and steel production than those of today, rational use of poorer quality ores for the expansion and development of iron and steel industry and so on.

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