THERMAL PROCESSES OF SELSMOGENE ZONE REVEALED BY THERMOCHRONOLOGY

热年代学揭示的火成岩带热过程

• 批准号: 12440137
• 负责人: TAGAMI Takahiro
• 金额: $ 1.15万
• 依托单位: KYOTO UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-12440137/
• 关键词: FISSION TRACK; THERMOCHRONOLOGY; EARTHQUAKE FAULT; PSEUDOTACHYLYTE; ZIRCON; NOSIMA FAULT; 領家帯; 平林トレンチ; 四万十帯

(1) FT's were significantly shortened nearby a fault both in the University 500m borehole at the Toshima site and Geological Survey of Japan borehole at the Hirabayashi site. This suggests that rocks along the fault were reheated into the zircon FT' partial annealing zone, sometime after the initial cooling of the Ryoke granitic rocks.(2) Zircon FT dating revealed that the reheating event took place at about 2 Ma for the University 500m borehole and at about 40 Ma for the Geological Survey of Japan borehole. The widths of reheated zones are about 3 m for the former and about 20 m for the latter. In conjunction with the deformation/alteration data of borehole rock, it is likely that the reheating was caused by the transfer and/or dispersion of hot fluids.(3) Laboratory hydrothermal heating experiment revealed that the annealing kinetics is indistinguishable between atmospheric and hydrothermal conditions.(4) A similar widespread zircon FT annealing was found for hanging wall of the Mozumi fault system.(5) In the upper boundary fault of the Okitsu melange of the Shimanto accretionary complex. FT's were significantly annealed for over 3 km distant away from the fault plane.

(1)在东岛大学的500米钻孔和平林县的日本地质调查局的一个断层附近，FT都显著缩短。这表明沿断层的岩石在Ryoke花岗岩初始冷却后的一段时间内被重新加热到锆石FT‘部分退火带。(2)锆石FT测年显示，大学500m钻孔的重新加热事件发生在大约2 Ma，日本地质调查局的重新加热事件发生在大约40 Ma。加热区宽度前者约为3m，后者约为20m。结合井壁岩石的变形/蚀变数据，很可能是由于热流体的迁移和/或扩散引起的。(3)实验室水热加热实验表明，大气和热液条件下的退火动力学没有区别。(4)墨子断裂系统的上盘也发现了类似的普遍存在的锆石FT退火。(5)在岛曼托增生杂岩的Okitsu混杂岩上边界断裂。FT在距断层面3公里以上的地方进行了显著的退火处理。

项目成果

Hasebe, N., Mori, N., Tagami, T. and Matsui, R.: "Geoological partial annealing zone of zircon fission-track system: additional constraints from the dccp drilling MITI-Nishikubiki and -Mishima"Chem. Geol.. in press. (2003)

Hasebe, N.、Mori, N.、Tagami, T. 和 Matsui, R.：“锆石裂变径迹系统的地质部分退火带：来自 dccp 钻探 MITI-Nishikubiki 和 -Mishima 的附加约束”Chem。

N.HASEBE: "Exhumation of an accretionary prism-results from fission track thermochronology of the Shimanto belt, southwest Japan."Tectonophysics. (in press). (2001)

N.HASEBE：“增生棱柱的挖掘——日本西南部四万十带裂变径迹热年代学的结果。”构造物理学。

T.TAGAMI: "(U-Th)/He geochronology of single zircon grains of known Tertiary eruption age"Earth Planetary Science Letters. 207. 57-67 (2003)

T.TAGAMI：“已知第三纪喷发年龄的单个锆石颗粒的（​​U-Th）/He 地质年代学”地球行星科学快报。

N.HASEBE: "Geological partial annealing zone of zircon fission-track s stem : additional constraints from the deep dulling MITI-Nishikubiki and -Mishima"Chemical Geology. (in press). (2003)

N.HASEBE：“锆石裂变径迹系的地质部分退火带：来自深度钝化 MITI-Nishikubiki 和 -Mishima 的附加约束”化学地质学。

T.TAGAMI: "(U-Th)/He geochronology of single zircon grains of known Tertiary eruption age"Earth and Planetary Science Letters. 207. 57-67 (2003)

T.TAGAMI：“已知第三纪喷发年龄的单锆石颗粒的（​​U-Th）/He 地质年代学”地球与行星科学快报。