Vol.9 No.2 2016
Research paper : Development of rock deformation techniques under high-pressure and high-temperature conditions (Koji MASUDA)−102−Synthesiology - English edition Vol.9 No.2 (2016) research are presented.4.1 Surface geological survey: using the geological record to construct a working hypothesis First, to construct a working hypothesis, processes that contribute to the phenomenon being investigated are inferred. To estimate a phenomenon occurring deep underground, strata that were previously located deep underground but are now exposed at the surface are surveyed and observed (Fig. 4). In some regions, ridges have formed, or a previously buried stratum has risen over a long period of time, and at such places, it is possible to observe at the surface rocks that were deep underground in the past. What is manifested at the surface is the result of processes such as deformation and fracture that occurred deep underground in the past. By carefully observing and analyzing such materials, that is, rocks and minerals and their structures, the processes that occurred in the past can be inferred. However, although the geology records the past, these records are only snapshots of the results of past processes; their evolution over time and the amount of time that has elapsed cannot be finely read by a geological survey. Therefore, it is necessary to construct a model and a working hypothesis from the physical and geological evidence about what processes occurred to produce the observed results. This research involves developing procedures for reproducing the processes read from the geological record and verifying the resulting model.Since the great earthquakes that cause major disasters repeat about every thousand years, changes must occur over Fig. 3 Relationships among the component technologies and the overall flow of the researchVisualize the effect of chemical reaction (water-rock reaction)Hypothesis verificationAcceleration of processIntegration of the technologies and reproduction of processes by a high-temperature and high-pressure rock deformation experimentHigh-temperature technology Effect of time Original developmentHigh-pressure technology Achieve high-pressure environment High-pressure gas technologySurface geological survey Past facts Estimation of the processMaterials testing technology Replicate deformation ExistingNew conceptVerificationIntegration of componentsComponent technologyWorking hypothesisFactFig. 4 Surface geological surveyA stratum that was deep underground in the past but is currently exposed at the surface (outcrop) is being surveyed. The photographs show an outcrop along the median tectonic line (Nagano Prefecture). The rocks, which were deformed while they were deep underground, are being sampled. Processes that might have occurred in the past are inferred by observing and analyzing rocks and strata that record the results of processes that occurred a long time ago while the rocks were deep underground.