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Research paper : The advanced geological researches and fundamental national land information (M. Saito)−19−Synthesiology - English edition Vol.3 No.1 (2010) to external evaluation by the Geological Society of Japan and others. To allow confirmation of reproducibility, raw data (such as traverse maps and borehole data) are published by GSJ as research reports, and the fossils and rock samples used are registered and stored at the AIST Geological Museum so they can later be validated by other researchers. Future development of a database to catalogue these raw data would facilitate this validation.5 Research elements in compilation of the GMJ Tomochi sheetIntegration of the research elements used in the creation of a GMJ 1:50,000 sheet is generally preceded by the following sequence of steps.1) Before the field survey, researchers conduct a literature search and use existing aerial photos and satellite images to identify surface geological and geomorphological features, such as active faults and terraces. Before our mapping of the Tomochi sheet started in 1995, we obtained and interpreted aerial photos published by the Geographical Survey Institute and satellite images recorded by the Japanese Earth Resource Satellite 1 (JERS-1).2) The field survey provides the basic data required for compilation of a geological map. To complete a field survey, geologists traverse the sheet area (usually on foot) looking for exposed rocks (outcrops) and record detailed observations of them. This field survey technique is most needed for the surveyor, but the know-hows are not available since it is difficult to describe them with words. The field survey approach used is of fundamental importance to the process, and varies greatly depending on the amount and type of exposed rock and the complexity of the geological structure. If the survey is in mountainous or hilly areas, the data is collected largely from outcrops near existing roads and paths, on ridges or valley floors (Fig. 5A). If the survey area is in flat country where there are few outcrops, borehole data acquired by government organizations becomes an important source of information.The first step of the geological field survey is to determine from the available outcrops the types of strata and rocks in the area. The relationships among these are then investigated. Understanding these relationships is a particularly important part of the process. The characteristics of individual rock units can be obtained from only small areas of outcrops, but it is essential to find the boundaries between rock units to determine the relationships among them. This is achieved by developing a geological model that takes into account the scientific literature, and landforms observed from aerial photos and satellite images. The geological model indicates where there may be geological boundaries, allowing the survey to focus on those areas and thus be conducted efficiently. Because a geological survey is an observation of nature, the observations often do not exactly match the model. Therefore, as new outcrop information is gathered, the geological model is revised in the mind of the researcher to fit the new data, and the survey continues with, if necessary, a shift in emphasis influenced by the changing model.Most of the Tomochi sheet area is mountainous, so the survey was conducted along roads, valley floors, and mountain ridges (see the traverse map of Fig. 5A). Although we expected the geology to be complex and the field survey to be time consuming, it was even more complex than we anticipated and required more time than was scheduled.3) In addition to field observations, rock samples and fossils are collected during field work. The subsequent analyses and interpretations of these are reflected in the final geological map. The rock samples are cut into thin sections (0.02−0.03 mm thick) for microscopic examination to identify the rocks from their constituent minerals and to extract evidence of deformation and metamorphism. Samples expected to contain microfossils are chemically treated to extract the microfossils which are then examined under the microscope. Other laboratory work includes separation and identification of heavy minerals and dating of the rocks by radio-isotope methods. Together, these data can reveal properties of the rocks such as their age and the environment in which they were formed, which cannot be obtained by field observations alone. The results are fed back to the actual field survey. These contributions to the production of a geological map correspond to the academic research (Type 1 Basic Research) conducted by universities, and if significant results are obtained, they are published as individual papers.The following subjects with relevance to the Tomochi sheet area were addressed by academic papers published before the creation of the GMJ.(1) Clarification of the stratigraphy and structure of the Lower Cretaceous Tomochi Formation[13](2) Identification of the basement of the Lower Cretaceous Tomochi Formation as the Permian accretionary complex[14](3) Identification of Devonian strata from the discovery of Leptophloeum, a Late Devonian fern[15](4) Clarification of low-pressure high-temperature metamorphism of the Higo Metamorphic Complex in the northern part of the Tomochi sheet[16](5) Discovery and description of megacrystalline clinopyroxenite[17](6) Discovery of jadeite and its relationship with surrounding rocks[18]Oral presentations to earth science and academic societies were also made on these and other related topics.

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