Structural Analysis of Deformation Texture Crustal and Upper Mamtle Materials and Rheology of the Earth

变形织构地壳和上幔物质的结构分析与地球流变学

• 批准号: 08454157
• 负责人: SATO Hiroki
• 金额: $ 2.5万
• 依托单位: Osaka University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1996
• 资助国家: 日本
• 起止时间: 1996 至 1998
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08454157/
• 关键词: peridotite; texture analysis; statistical analysis; particle paramenter; self-similar; rheology; detormation process; limestone; かんらん岩; ファブリック; 岩石組織; 異方性; 分布関数; 相関関係; 画像解析ソフト; 流動組織; 面構造; 地震波速度異方性; 地殻・上部マントル岩石; 鉱物の配向

We analyzed texture of a peridotite sample, and investigated deformation process in the upper mantle. The peridotite sample shows P-wave velocity anisotropy of 7-8 % due to preferred orientation of olivine. In order to determine distribution of grain size, area S, perimeter P and aspect ratio of olivine in peridotite, more than 2000 grains are statistically analyzed. Average values (and standard deviations) of aspect ratio, roundness and mean diameter are I..83 (0.48), 0.66 (0.58) and 59.1 (52.7) mum, respectively. Histograms of the particle parameters generally fit to the Gamma distribution function. Correlation between particle parameters is observed ; e.g., perimeter is proportional to area as P^<alpha> S^<0.54>. The shapes of olivine grains are self-similar, and the fractal dimension is about 1.1. Further, fabric analysis of olivine shows that large relict grains are oriented against their slip systems and are not subject to deformation. However, small grains are recrystallized because their orientation is not against the slip systems. As such, grain size depends on lattice orientation of olivine.We also analyzed deformation texture of a limestone. Particle parameters were determined for the thin sections parallel (XY-plane) and perpendicular (XZ-plane) to the foliation. Lineation is clear in the XZ-plane ; however, no lineation is observed and calcite is equi-granular in the XY-plane. In fact, we obtain average aspect ratio and roundness of 1.91 and 0.55, respectively, for the XZ-plane, and of 1.68 and 0.57 for the XY-plane.

我们分析了橄榄岩样本的结构，并研究了上地幔的变形过程。由于橄榄石的择优取向，橄榄岩样品显示出 7-8% 的 P 波速度各向异性。为了确定橄榄岩中橄榄石的粒度、面积S、周长P和长径比的分布，对2000多个橄榄石颗粒进行了统计分析。长径比、圆度和平均直径的平均值（和标准偏差）分别为 I..83 (0.48)、0.66 (0.58) 和 59.1 (52.7) μm。粒子参数的直方图通常符合伽玛分布函数。观察颗粒参数之间的相关性；例如，周长与面积成比例，为 P^<alpha> S^<0.54>。橄榄石颗粒的形状是自相似的，分形维数约为1.1。此外，橄榄石的组织分析表明，大的残余颗粒沿着其滑移系统定向，并且不会变形。然而，小晶粒会再结晶，因为它们的取向不与滑移系统相反。因此，晶粒尺寸取决于橄榄石的晶格取向。我们还分析了石灰石的变形结构。确定与叶状平行（XY 平面）和垂直（XZ 平面）的薄片的颗粒参数。 XZ平面内线条清晰；然而，没有观察到线纹，并且方解石在 XY 平面上是等粒状的。事实上，我们获得的 XZ 平面的平均长宽比和圆度分别为 1.91 和 0.55，XY 平面的平均长宽比和圆度分别为 1.68 和 0.57。

项目成果

Akira Hasegawa: "Seismic activity and deformation process of the crust within the overriding plate in the northeastern Japan subduction zone" Tectonophysics. (印刷中). (1999)

Akira Hasekawa：“日本东北部俯冲带上覆板块内的地震活动和变形过程”构造物理学（1999 年）。

Hiroki Sato: "Where does magma come from? -Three-dimensional distribution of partial melt in the mantle" Earthquake Journal. 23. 17-22 (1998)

佐藤宏树：“岩浆从哪里来？-地幔中部分熔融物的三维分布”《地震杂志》。

佐藤博樹: "地震波速度機構によりとらえられた沈み込み帯のマグマ" 地質ニュース. 517. 30-37 (1997)

Hiroki Sato：“地震速度机制捕获俯冲带中的岩浆”地质新闻 517. 30-37 (1997)。

佐藤博樹: "高圧下における地殻・上部マントル岩石の弾性波速度異方性" 火山. 42. S123-S130 (1997)

Hiroki Sato：“高压下地壳和上地幔岩石的弹性波速度各向异性”火山42。S123-S130（1997）

Akira Hasegawa: "Seismic activity and deformation process of the crust with in the orerriding plate in the nor theastern Japan subduction zone" Tectonophysics. 印刷中. (1999)

长谷川彰：“日本东北部俯冲带的地壳地震活动和变形过程”，《构造物理学》，1999 年出版。