Analysis of rock microtectonics and anisotropy

岩石微构造和各向异性分析

• 批准号: 12640467
• 负责人: SATO Hiroki
• 金额: $ 1.09万
• 依托单位: Osaka University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 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/grant/KAKENHI-PROJECT-12640467/
• 关键词: mineral-fluid system; hydrothermal; partial melt; elastic-wabe velocity; Vp; Vs; low-velocity zone; velocity structure; rock physics; Vs-Vp; Vsダイヤグラム; 蛇紋岩; 含水鉱物; H_2O流体; 岩石-流体系の微細構造; 流体分布の解析; 脱水過程; フラクタル解析; 統計解析; 対数正規分布; 面構造; 流動組識; 方

H_2O-fluid distributions in rocks critically control rock textures and microtectonics. We have shown that physical properties of fluid-bearing rocks can be estimated from the properties of mineral-fluid systems. The properties of the crust and the upper mantle are, therefore, estimated from the properties of quarts-feldspar-fluid, pyroxene-amphibole-fluid, and olivine-pyroxene-fluid systems. Here fluid is either H_2O or partial melt.In the Japan subduction zone, H_2O or partial melt causes low velocity in the crust and the upper mantle : Elasticity data of crustal and mantle minerals and of H_2O and silicate melts have been determined at high pressures and temperatures. Those data can be used to estimate elastic-wave velocities of fluid-bearing crust and mantle rocks.P-wave to S-wave velocity ratios, Vp/Vs, of mineral-melt systems are higher than those of mineral-H_2O systems. This is because the bulk modulus of silicate melt is about an order of magnitude larger than that of H_2O. Seismic tomographic studies have shown that Vp/Vs is generally high in the upper mantle low-velocity zone, indicating the presence of partial melt. On the other hand, Vp/Vs is low in the upper crustal low-velocity zone. We suggest that H_2O fluid causes low velocity in the upper crust.

岩石中的H_2O流体分布严格控制岩石结构和微构造。我们已经证明，含流体岩石的物理性质可以根据矿物流体系统的性质来估计。因此，地壳和上地幔的性质是根据​​石英-长石-流体、辉石-角闪石-流体和橄榄石-辉石-流体系统的性质来估计的。这里的流体要么是H_2O，要么是部分熔融。在日本俯冲带，H_2O或部分熔融导致地壳和上地幔速度较低：地壳和地幔矿物以及H_2O和硅酸盐熔体的弹性数据已经在高压和温度。这些数据可用于估计含流体地壳和地幔岩石的弹性波速度。矿物熔体系统的纵波与横波速度比Vp/Vs高于矿物-H_2O系统。这是因为硅酸盐熔体的体积模量比H_2O大约大一个数量级。地震层析研究表明，上地幔低速区Vp/Vs普遍较高，表明存在部分熔融。另一方面，上地壳低速区Vp/Vs较低。我们认为H_2O流体导致了上地壳的低速。

项目成果

竹内 均: "地球環境調査計測事典"フジ・テクノシステム. 663-671 (2002)

Hitoshi Takeuchi：“全球环境研究和测量百科全书”Fuji Technosystem 663-671 (2002)。

Hiroki Ito: "Animated three-dimensional structure of the Earth's interior for research and education"Mathematica Journal. 8. 574-585 (2002)

Hiroki Ito：“用于研究和教育的地球内部动画三维结构”Mathematica 杂志。

Hiroki Sato: "Animated three-dimensinal structure of the Earths interior for research and education"Mathematica Journal. (印刷中). (2001)

Hiroki Sato：“用于研究和教育的地球内部动画三维结构”Mathematica 杂志（2001 年）。

Yukihito Imada: "Velocity anelasticity and texture analysis of rocks"EOS Transactions, American Geophysical Union. 81. 202-203 (2000)

Yukihito Imada：“岩石的速度迟弹性和纹理分析”EOS Transactions，美国地球物理联盟。

Hiroki Sato: "Mathematica as a powerfeel and practical tool for displaying animated three-dimensional structures of the Earth's interior"Geochemistry Geophysics Geosystems. (in print). (2003)

Hiroki Sato：“Mathematica 是一种强大而实用的工具，用于显示地球内部的动画三维结构”地球化学地球物理学地球系统。