Basement structure and active fault system in the Inner zone of Southwest Japan

日本西南部内部地带的基底结构和活动断裂系统

• 批准号: 11640452
• 负责人: HAYASAKA Yasutaka
• 金额: $ 1.98万
• 依托单位: Hiroshima University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11640452/
• 关键词: Active fault; Basement geology; Earthquake forecast; Inner zone of Southwest Japan; Tamba terrane; Asaji metamorphic rock; Island arc crust; Western Tottori earthquake; 舞鶴帯; 島弧地殼

1. Exploration of deep-seated graniteAnalytical technique for the volatile elements (B, F, Cl) in mudstone by XRF was developed with the purpose of verifying deep-seated granite in the accretionary complex terrane. Tamba terrane was examined using this technique, and confirmed that the high concentration of those volatile elements in northern Kameoka area showing the existence of deep-seated granite.2. Newly found large scale geologic structure in the Pre-Cretaceous Terranes(1) A large-scale high angle fracture zone was found between the Maizuru and Akiyoshi zones in Ooe-cho area, northern Kyoto Prefecture.(2) The Sangun metamorphic rocks are overlain by a low angle nappe of the Maizuru zone fomations in the Kagamino-cho area, Okayama Prefecture.(3) The Pre-Cretaceous Terranes in Kohfu-cho area where the epicentral region of the Western Tottori earthquake outbreaked in October 2000, are composed of weekly metamorphosed melange formations, and they can be correlated to the Hida-gaien zone.(4) Allochthonous Kanmon Group is intercalated in the Maizuru zone embedded in two WNW-ESE trending faults in the Hikimi-cho area, Shimane Prefecture. This suggests the existence of the early Cretaceous large-scale wrench fault along the Maizuru zone.3. SummaryGeometrically strictly to say, the active fault system is not in a block structure. Accretionary complex crust is surrounded by the granitic crust forming frame work structure in the Chubu to eastern Kinki district, at where much of active faults develop in the granitic crust or its marginal part. WNW-ESE trending zonal arrangement of granitic crust and accretionary complex crust is distinct in the western Kinki. Some active faults show parallel alignment along the above mentioned zonal arrangement. Most of active faults had re-activated by the ancient faults formed in late Cretaceous in the Chugoku to northern Kyushu. They show inversion of displacement sense caused by the conversion of the stress field.

1、深部花岗岩勘探开发了泥岩中挥发性元素（B、F、Cl）XRF分析技术，旨在验证增生复杂地体中的深部花岗岩。利用该技术对丹波地体进行了检测，证实了龟冈北部地区这些挥发性元素的高浓度，表明存在深层花岗岩。 2．新发现的前白垩纪地体大型地质构造(1)京都府北部大江町地区的舞鹤带和秋吉带之间发现了大规模的高角度断裂带。(2)冈山镜野町地区的三群变质岩被舞鹤带地层的低角度推覆体覆盖 (3) 2000年10月鸟取县西部地震震中地区甲府町地区的前白垩纪地体由周变质混杂岩地层组成，可与飞騨外苑带进行对比。(4) 异地关门群夹插在两个WNW-ESE的舞鹤带内 岛根县引见町地区的趋势断层。这表明舞鹤地带存在早白垩世大型扳手断裂。3．小结严格地讲，活动断层系统并不呈块状结构。中部至近畿东部地区，增生复合地壳被花岗岩地壳包围，形成框架结构，这里的花岗岩地壳或其边缘部分发育许多活动断层。近畿西部花岗岩地壳和增生杂岩地壳的WNW-ESE走向地带性排列明显。一些活动断层显示出沿着上述带状排列的平行排列。大多数活动断层是由中国到九州北部白垩纪晚期形成的古断层重新激活的。它们显示了应力场转换引起的位移感反演。

项目成果

Hayasaka, Y.: "Some geological problem on the Maizuru terrane, Inner zone of Southwest Japan."Monograph. 49. 81-91 (2000)

Hayasaka, Y.：“日本西南部内陆地区舞鹤地体的一些地质问题。”专着。

Kameda, J.: "Geoloey of Northern Sakhalin, Russia and its Relation to the Relative Convergence between the Eurasia and North America Plates."Journal of Geography. 109. 235-248 (2000)

Kameda, J.：“俄罗斯萨哈林岛北部的地质及其与欧亚板块和北美板块相对辐合的关系。”地理学杂志。

Hayasaka, Y.: "The phenomenalistic description of the nappe boundary in the Inner zone of Southwest Japan."Chikyu. 36. 75-81 (2002)

Hayasaka, Y.：“日本西南部内陆地区推覆边界的现象学描述。”Chikyu。

早坂康隆: "西南日本の地震基盤の地質学的特性"月刊地球. 22巻. 7-12 (2000)

早坂康隆：“日本西南部地震基底的地质特征”，地球月刊，22. 7-12（2000）。

早坂康隆: "ナップ境界の現象論-西南日本内帯を例に-"月刊地球. No.36. 75-81 (2002)

早坂康隆：“推覆边界的现象学——以日本西南部内带为例——”地球月刊第36期。75-81（2002）。