Evolution of the Hida metamorphic rocks from the view point of clinopyroxene mineralogy

从单斜辉石矿物学角度看飞弹变质岩的演化

基本信息

批准号：
06640613
负责人：
SOHMA Tsuneo
金额：
$ 0.9万
依托单位：
Toyama University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
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

项目摘要

Evolution of the Hida metamorphic belt was discussed from the view point of clinopyroxene mineralogy. Followings are major conclusions.1. Clinopyroxene gneiss of the Hida metamorphic belt was formed by mechanical mixing of metabasite and limestone, thereby the reaction tr+cc+qz=di+H2O+CO2 takes place. Inishi-type rocks include both the product of the mechanical mixing of the rocks and that of dyhydration melting of amphibolite.2. Mechanical mixing of rocks is a major process of metasomatic reaction. This process results in the compositional change of system, and therefore metamorphic reactions due to the difference between the free energy of simple mixture of rocks and that of products take place. This type of metamorphic reactions is of non-isochemical reaction, being in contrast to a general view that metamorphic reactions take place in response to the change of temperature and pressure within isochemical system.3. The concept of non-isochemical reaction extends to fluid bearing systems. We found that the metamorphic reactions by mechanical mixing of rocks results in the abrupt release and compositional change of fluid phases, and consequetly different reactions may occur.4. Mechanical mixing of rocks leading to the non-isochemical metamorphic reactions is enhanced by accretionary process at the leading edge of continents, in other words, continental mobile belts. Since non-isochemical reactions are of irreversible processes, the petrological properties of continental mobile belts continue to be progressively chanced upon Wilson cycle.

从Clinopyroxene矿物学的角度讨论了HIDA变质带的演变。以下是主要结论。1。 HIDA变质带的Clinopyroxene片麻岩是通过机械混合和石灰岩的机械混合而形成的，从而发生了反应TR+CC+QZ = DI+H2O+CO2。 Inishi-Type岩石既包括岩石的机械混合的产物，也包括闪石染色熔融的含量。2。岩石的机械混合是分代反应的主要过程。该过程导致系统的组成变化，因此由于岩石的简单混合物和产品的自由能之间的差异而导致变质反应。这种类型的变质反应是非同化反应的，与一般观点相反，即变质反应响应于等级化学系统内的温度和压力的变化而发生。3。非同化反应的概念扩展到流体轴承系统。我们发现，通过机械混合岩石的变质反应会导致流体阶段的突然释放和组成变化，并且可能发生了不同的反应。4。岩石的机械混合通过在大陆的前沿的增生过程，换句话说，大陆移动带的前缘增强了导致非同化变质反应的岩石的机械混合。由于非化学反应是不可逆转的过程，因此在威尔逊周期中，大陆移动带的岩石学特性继续逐渐被造成。