Vol.3 No.1 2010

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Research paper−13−Synthesiology - English edition Vol.3 No.1 pp.13-25 (Jul. 2010) in the field of geology and geological mapping mean that the cooperation of several geologists with specialized knowledge is needed. Further, greater geological accuracy and professional result of research of individual rocks and strata are demanded than was the cases in the past. All strata and rocks must be unambiguously integrated to provide a plausible geological evolution of the area mapped. In this paper, I discuss the synthesis and production of a GMJ 1:50,000 sheet from original geological survey data using as an example the Tomochi 1:50,000 sheet in central Kyushu (Figs. 1 and 6), the most geologically complicated GMJ 1:50,000 sheet that has been published recently. I also discuss how GMJ sheets are used for the benefit of Japanese society.2 Our research objectivesThe overall objective for our geological mapping of the GMJ 1:50,000 sheet was to apply state-of-the-art geological concepts to new field survey data. Other objectives were to clarify the relationship of the rocks of each GSJ 1:50,000 sheet to the wider regional geology and to create a new standard for production of 1:50,000 geological maps in each region. Production of the Tomochi sheet is also part of a plan to methodically increase the GMJ 1:50,000 scale coverage to eventually cover the whole of the Japanese Archipelago. Even if new 1:50,000 mapping does not produce dramatically different conclusions to past mapping, integration of new survey data clarifies the broad regional geology and is an important result of the GMJ program, which also has considerable significance for Japanese society.1 IntroductionGeological maps provide fundamental information about the Earth. They show the type, age of formation, configuration, and interrelationships of the rocks beneath vegetation and surface soil. In Japan, the Geographical Survey Institute (Ministry of Land, Infrastructure, Traffic and Tourism) is responsible for topographic mapping of the onshore land surface and landlocked bays and publishes topographic contour maps. The Hydrographic and Oceanographic Department of the Japan Coast Guard is responsible for mapping the ocean floor and publishes bathymetric charts. The Geological Survey of Japan (GSJ) looks beneath the surface of the Earth and gathers information to publish geological maps. These geological maps provide fundamental data for many uses in Japan, including resource exploration, disaster prevention, civil engineering, environmental protection, and academic research.The basic geological maps published by GSJ are rectangular Geological Map of Japan (GMJ) sheets, which are defined by a grid of longitude and latitude, and are mostly at scales of 1:50,000 or 1:200,000. Maps at 1:50,000 scale are prepared from original geological survey data, whereas those at 1:200,000 scale cover a wider area and are created by sorting, selecting, and integrating (the process of compilation) the geological information from GMJ 1:50,000 sheets and other sources.There is a variety of strata and rocks within most rectangular map sheet areas. In the past, one geologist could complete the survey for a GMJ 1:50,000 sheet. However, recent advances - Development process of the Geological Map of Japan 1:50,000 -Makoto SaitoInstitute of Geology and Geoinformation, AIST Tsukuba Central 7, 1-1-1 Higashi, Tsukuba 305-8567, Japan E-mail : Original manuscript received September 11, 2009, Revisions received October 27, 2009, Accepted November 2, 2009The Geological Map of Japan 1:50,000 shows fundamental national land information of the subsurface materials of the district, and is multifariously used for resources development, disaster prevention, siting of industrial activities, environment protection, and as the geological standard of the district. It is important basic information for understanding natural environments scientifically and is essential information for the sustainable development of Japan. While geological maps mostly made by universities or companies are for understanding specifically interesting strata or rocks, the 1:50,000 geological maps made by GSJ, AIST comprehensively integrate research results of all strata and rocks in the district and explain the geological evolution of the district. There has never been any paper describing the process in developing the 1:50,000 geological map, which integrates geological research for the district. The author shows his own development process with the 1:50,000 geological maps as examples.The advanced geological researches and fundamental national land informationKeywords : Geological map, 1:50,000, integration, geology, process, Tomochi[Translation from Synthesiology, Vol.2, No.4, p.321-331 (2009)]

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