Formation mechanism of ecologites and the related high- and ultrahigh-pressure metamorphicrocks

对俯冲碰撞构造背景下的榴辉岩及与之相关的高压、超高压变质岩进行了地质、岩石学和年代学研究。在详细野外填图的基础上，对作为古俯冲带变质带代表的三百川变质带进行了详细的研究，特别是在四国东部的别石地区和高津地区。在构造地质、地质年代学、变质条件和温压演化等方面进行了精细的研究。中国苏鲁带中的高压、超高压变质岩作为碰撞带变质带的代表也得到了深入的研究。在本研究的最后阶段，对俯冲带和碰撞带变质岩的变质过程和折返机制进行了对比。2001年9月，本研究的首席研究员Akira Takasu和研究员Takao Hirajima在日本四国的新滨、Doi和Bessiyama组织了第六届国际榴辉岩会议(第6届IEC)。来自世界17个国家的120多名研究人员参与了这项研究。会议包括科学会议(3天)和实地讨论(2天)，地点在贝什区，那里暴露了几种类型的生态岩。在会议上进行了56次口头介绍和65次海报介绍。在会议上提交的重要论文和这项研究的部分成果将发表在国际期刊《LITOS》特刊(Takasu，A.，Hirajima，T.等(编辑))上，现已进入最后编辑程序，并将于近期出版。

Geological, petrological and geochronological research on eclogites and the related high- and ultrahigh-pressure metamorphic rocks from the subduction and collision tectonic settings has been done. The Sanbagawa metamorphic belt, especially in the Besshi district, central and Kotsu district, eastern Shikoku, as a representative of the metamorphic belt of an ancient subduction zone has been studied based on detailed field mapping. Precise studies on structural geology, geochronology, estimation of metamorphic conditions and P-T evolution have been done. The high- and ultrahigh-pressure metamorphic rocks in the Sulu belt in China have been also studied intensively as a representative of a collision zone metamorphic belt. The subsequent comparison of metamorphic process and exhumation mechanism among the subduction zone and the collision zone metamorphic rocks has been done at the final stage of this research.Akira Takasu of the head investigator and Takao Hirajima of an investigator of this research organized the Sixth International Eclogite Conference (6th IEC) held in Niihama, Doi and Bessiyama in Shikoku, Japan in September, 2001. More than 120 researchers were participated from 17 countries in the world. The conference included scientific session (3 days) and field discussion (2 days) at the ecologite localities in the Besshi district, where several types of ecologites are exposed. 56 oral and 65 poster presentations were done at the sessions. The important papers presented at the Conference and a part of the results of this research will be published in an international journal, special issue of Lithos (Takasu, A., Hirajima, T. and others (eds.)), now it is in the final editing procedure, and will be appeared very recently.