Modeling for the development of the crust

地壳发育建模

• 批准号: 06302031
• 负责人: HIRAJIMA Takao
• 金额: $ 3.26万
• 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: 1994
• 资助国家: 日本
• 起止时间: 1994 至 1996
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-06302031/
• 关键词: Memamorphism; Modeling; P-T path; Rock texture; Migmatite; Ultrahigh-pressure rock; p-t経路

This research was organized to construct a quantitative nemerical model for repressenting the rock forming mechanism and kinematic process in the lower crust using the high quality natural data on petrology, mineralogy, geochemistry and continuum dynamics. The study group is composed of a "data collection" group and "modeling" group.1) In Sanbagawa belt, the difference of subduction path between neighboring regions is deciphered. It became clear that the direction of the uplift of the belt is parallel to the trend of the subduction direction.2) In Abukuma and Ryoke belts, partial melting took place in a wider area of the higher grade parts than hitherto recognized. New dating techniques such as SHRIMP and CHIME make clear the protolith and metamophic timings of these belts. Many sector zoned garnets were found from the higher grade parts of these belts. The growth of such garnet and the abrupt texture change from schistose to gneissose in the higher grade parts were ascribed to the par … More tial melting of crustal material in the higher grade part. An hypothesis on the thermal source of the Ryoke belt ascribed to the subduction of the oceanic ridge was denied by this study.3) In the Su-Lu region, the transition of igneous rocks to ultrahigh pressure (UHP) rocks, and the overprinting of medium pressure (MP) assemblage on the UHP rocks are clarified, which demonstrated that some MP orthogneiss of the Su-Lu region were once located in the depth of 100km depth and that the decomposition process of UHP rocks are fairly rapid without significant cooling.4) 2-dimensional X-ray mappings reveal that the irreversible crystallization in over-saturated system, realized by overstepping of univarinat line, is common even in the higher grade metamorphic rocks, and that the element exchange took place even in the core of the garnet in the lower grade rock. These fact suggest that the careful treatment is need to determine the P-T-t path of metamorphic rock by inversion analyzes.5) These data give quantitative constraints on the modeling. The guide line for producing the quantitative numerical model for explaining various physical phenomenons in the lower crust is proposed. Less

这项研究的组织是为了构建一个定量中性模型，用于使用岩石学，米拉科，地球化学和持续动态的高质量自然数据在下层地壳中代表岩石形成机制和运动学过程。研究组由Sanbagawa带的“数据收集”组和“建模”组组成。1）决定了邻近区域之间的俯冲路径差。很明显，皮带的升高方向与俯冲方向的趋势平行。2）在Abukuma和Ryoke带，部分熔化发生在更高级别的零件的更大区域，而不是迄今为止所认识的。新的约会技术（例如虾和铃声）清楚地表明了这些皮带的原始时间和变质时机。从这些皮带的高级部分中发现了许多扇区的树枝。这种石榴石的生长和从高年级零件中的斑点变成片麻岩的突然​​质地的变化被分配给了PAR…在高级部分中，地壳材料的更多融化。这项研究否认了关于分配给海洋山脊俯冲俯冲的Ryoke带的热源的假设。3）在Su-Lu地区，火岩向超高压力（UHP）岩石的过渡，以及在UHP Rocks上的中等压力（MP）组合的过度澄清的UHP岩石上的某些MP或某些MP的启动，该地区的某些MM均为澄清，以至于某些MM均为某些MP，曾经是在某些MP上置于某些MP的依据。 100km的深度和UHP岩石的分解过程很快而没有明显的冷却。4）二维X射线映射表明，过度饱和系统中不可逆的结晶，通过超平台的Univarinat系列实现，即使在较高的级别的变质岩石中也很常见，甚至在较高的元素上也是如此。这些事实表明，需要仔细的处理来通过反转分析来确定变质岩石的P-T-T路径。5）这些数据对建模给出了定量限制。提出了用于产生定量数值模型的指南，以解释下层地壳中的各种物理现象。较少的

项目成果

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