Geochronology of paleo-earthquake -dating of fault materials by earthquake-

古地震地质年代学 - 通过地震对断层物质进行测年 -

基本信息

批准号：
11440151
负责人：
ITAYA Tetsumaru
金额：
$ 6.14万
依托单位：
Okayama University of Science
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B).
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2000
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-11440151/
关键词：
earthquake fault materials fault gouge mica-clay minerals K-Ar method Ar-Ar method TL method ESR method 年代測定放射線損傷法断層シュードタキライト

项目摘要

This is to date the materials formed during fault movement accomapnied with paleo-earthquakes by K-Ar, Ar-Ar and radiation damage methods after the identification of fault rocks formed by earthquakes.In order to estimate natural radiation level in TL and ESR dating, a portable γ-ray meter was purchased. We also constructed the automated laser step heating system for Ar-Ar dating of single mineral grain.Many structural geologists supported us for sampling of fault rocks, mainly pseudotachlytes from Oshima of Ehime Prefecture and fault gouges from Atotsugawa, Hatagawa, Tasuke and Tanakura systems in Japan, and from MCT in Nepal and Yangsan fault in Korea.Oshima pseudotachlytes and their host metamorphic rocks were dated with the Ar/Ar spot daing method using a pulsed laser. The later results give 100-110Ma for amphiboles and the former, 60-80Ma. The ages of gouges are about 3Ma for the Nepal MCT, 40-50Ma for the Tanakura, 38-46Ma for the Yangson. In the Atotsu system, the ages become younger with decreasing grain size of separates from granites. This tendency is not observed in the separates from sedimentary rocks. However, the ages are about 60Ma.We examined the discordant age relations due to K ion trapped in the expanded layers of smectite When K ion is exchanged by NH4 ion, the ages get 2-5% older than those of the original smectite.We have published more than 20 papers on the results of this project and the related subjects.

迄今为止，这是迄今为止，在识别地震形成的断层岩石之后，通过K-AR，AR-AR和辐射损伤方法积累的故障运动中形成的材料。在为了估算TL和ESR测定中的自然辐射水平，可在TL和ESR测定中进行自然γ射线仪表中的自动级别构建的构建量的构建频率，用于自动加热系统，用于自动级别的旋转系统。故障岩石的采样，主要是来自ehime县奥希马的伪造和日本阿托托瓜（Atotsugawa），哈塔川（Hatagawa），塔豪（Hatagawa），塔索（Tasuke）和田纳库拉系统（Tanakura Systems）的故障g，以及尼泊尔和扬山（Yangsan）的MCT和Yangsan中的MCT和Yangsan的过失。激光。后期的结果可为闪石和前者提供100-110mA，60-80mA。尼泊尔MCT的Gouges年龄约为3MA，Tanakura的40-50mA，Yangson的38-46mA。在Atotsu系统中，随着花岗岩分离的晶粒尺寸降低，年龄变得更年轻。在与沉积岩的分离中未观察到这种趋势。但是，年龄大约为60mA。我们检查了由于NH4离子交换K离子而被困在蒙脱石层中的k离子而引起的不一致的年龄关系，年龄比原始的晶状石年龄比原始的sectite的年龄要比原始的sectite年龄2-5％。我们在该项目的结果及相关主题上发表了20多篇论文。