複雑系科学である地質学における武谷三段階論の有効性 堆積学、環境問題に関わる地質学的例を取り上げて--複雑系科学としての地質学 その3--

Abstract

According to the Takaetani's "three-stage theory" scientific recognition should be carried out through three stages; 1 the "phenomenological stage", 2 the "substantial stage" and, 3 the "essential stage". This theory is concerned originally with non-complex systems but can also be adapted to the study of complex systems also. A few examples are, 1: The contrary tendency problem among decrease of grain sizes and compositional maturity of the Permian and Triassic sandstones in the Maizuru belt was solved by investigation of the inner "substantial" structure of the stones. The grain sizes of the constituent minerals of the sediments were controlled essentially by the characteristics of substantial constituent crystals. 2: Mo content distribution in sediments of Lake Shinji researched by Yasumatsu (1973) provides another example showing the importance of trance-level investigation. Mo is concentrated substantially in fine clay-size sediments around a river mouth. 3: As and Pb were found in the water discharge tunnel which was planned to strengthen the discharge ability of Amagase dam. The source and the substantial state of the elements in the samples was not checked by the relevant government department. Therefore city offices could not offer any exact information about environmental pollution to citizens. These examples show the importance of substantial studies. The combined consideration of two concepts, the "system formation level concept" and the "three stages of recognition theory" is a strategically effective way to understand various complex systems.