Simulated Organic Metamorphism in Diagenetic to Burial Metamorphic Stage.

本研究原计划是在高温加热炉的基础上，辅以足够的助学金资金支持，利用大型三轴岩石力学试验机进行有机变质模拟实验。由于财政支持的意外减少，原计划不得不改革和取代预期的大规模模拟实验作为巨大的实验结果。为了取代预期的实验室实验来代替自然地质现象，九州两个具有显著不同构造历史的特色大地构造省，其外层的岛本增生体和靠近Usuki-Yatsushiro构造线(M.T.L.)的中轴体具有显著的构造历史。作为实验对象。野外修正研究和辅助小规模实验室实验表明，镜质组反射率作为有机变质作用的参数之一，在岛曼吸积岩体中，从变质阶段到变质阶段的最小镜质组反射率(Rmin)表现出与菲律宾海板块俯冲运动引起的应力方向平行的较强的规律性。另一方面，中轴体从变质阶段到变质阶段的最小镜质组反射率(Rmin)即使在一个位置也表现出不同的方向，这不是单一加热过程中的简单变形，而是多方向的位移和多变质热蚀变。由于实验室实验研究的不足，对变形过程中的温度和压力水平的研究结果仍然是定量的，这为以后的研究奠定了基础。

Original plan of this study attempted to apply a large scale triaxial rock mechanical testing machine for simulated organic metamorphic experiment if high temperature heating vessel was supplemented by sufficient financial support of the grant-in-aid. Owing to unexpected curtail of the financial support, the original plan had to reform and substitute characteristic natural geological phenomena as gigantic experimental result for the expected large scale simulated experiment.In order to replace the expected laboratory experiment to natural geological phenomena, two characteristic geotectonic provinces in Kyushu that have remarkable different tectonic history of the Shimanto accretionaly body in the outer zone and the central axial body near the Usuki-Yatsushiro Tectonic Line (M. T. L.) were adopted as the experimental target. The revised studies on the fields and an auxiliary small scale laboratory experiment have revealed rather satisfactory result by applying the vitrinite reflectance as one of the parameters of organic metamorphism.In the Shimanto accretionaly body, minimum vitrinite refrectance (Rmin) ranging from catagenetic to metamorphic stage shows rather regular pattern parallel to the direction of stress caused by the subducting movement of the Philippine Sea plate. On the other hand, minimum vitrinite reflectance (Rmin) ranging from catagenetic to metagenetic stage in the axial body shows different directions even at one location, which can be attributed not to simple deformation in a single heating process, but to multi-directional displacement and polymetamorphic thermal alteration. The results still remain quantitative solution on temperature and pressure levels during the deformation owing to insufficient laboratory experimental studies which is succeeded to future research.