As a result of the actual survey of Yubari Coal Field the following proof was obtained in order to presume the intratelluric geological structure. The Paleogene Series lies generally conformably on the Cretaceous System and the structure of the latter is reflected on the former. But, in case where the barrier existed the top of the Cretaceous System was eroded out. Sedimentary materials of the Cretaceous System came from the west and those of the Paleogene Series came from the east. Thus, the former was accumulated on the west side of the barrier, and the latter on the east. Ferruginous materials of tuff contained in some of these sedimentary materials have reducing phases indicating that such an environment existed in the embayment. The basis of these arguments has been applied to Ishikari Coal Field, a larger coal field which includes Yubari Coal Field, and the following presumption of the geological structure has been made. It was discovered on the map that the arrangement of Anticline Series formed a shape of waterrings extending westward of which the land surface of the inner three series consist of Paleogene Series. The coal contained therein had been mined out and the structure was confirmed. And their two outer series on the land surface are covered by a Neogene series the Anticlinal Axis is not clear except that the warped formation coincides with the High Anomaly Zone which was discovered by the gravity survey. The Cretaceous System is expected to exist about 700 m below the land surface. Several possible cases of the geological structure was considered on the basis of those directly observable facts comparing those with the indirect evidences and finally the most harmoniously agreed case was selected and finally but tentatively a conclusion was attained regarding the intratelluric geological structure. (Of course direct materials take precedence of indirect ones.) However, it can not be asserted true. Truth can first be approached when useful minerals are explored and mined according to this conclusion. Fortunately, there is a strong possibility that there exists dormant petroleum in the Cretaceous System of this district.
The land planning in Japan since the termination of war has generally been done based on the Multi-Purpose Land Development Law enacted in 1950. The areas for multi-purpose development were designated in 1951 in accordance with the said law. The projects are now being executed in 21 regions in the country. Several tentative drafts have been worked out and examined for the nation wide land development planning and it is expected to be finalized in the near future. As for the prefectural development planning, plans are not necessarily formulated in accordance with the said law but on the basis of the intentions of the respective prefectures. Most of the prefectures have already completed their plans. A new law is now being framed for planning development of cities and their environs and new industrial areas. For future development of regional planning, it is essential to consolidate and coordinate the relevant laws and administrative organizations.