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西格陵兰中部伊索托克(Isortoq)杂岩中的粗玄武岩墙已遭受高角闪岩相至石榴麻粒岩相的变质作用。对这些岩墙的详细采样和岩石学研究表明,在单个的岩墙中可出现完全的组合序列,角闪岩相组合通常限于岩墙的边缘,石榴麻粒岩相岩石产在岩墙的核部,辉石麻粒岩相介于前两者之间。所有共存相的电子探针分析表明,由角闪岩相组合前进到麻粒岩相组合导致从角闪石中大致以2∶1的比例分离出浅闪石和契尔马克组份。反应作用发生后由于新相的出现,随着角闪石的崩解其中元素丰度发生了系统的变化。除岩墙中组份的系统变化外,少量的代数变动容许推导出六种平衡,这些平衡提供了在高级变质条件下玄武质岩石变质作用的一种总模式,该模式采取理想组合序列的形式,理想组合序列将根据 X_(H_2O),温度和/或固体压力(区域的)梯度表示出来。这些平衡的分析表明,不同的二氧化硅活度和 Fe~(2+)—Mg~(2+)的交换将改变反应的化学计算法,将影响角闪石崩解反应中浅闪石与契尔马克的比例,而且也会改变生成的斜长石成分。这些变量连同水逸度的变化将局部改变理想组合的序列,并且将解释自然高级区变基性岩中所观察到的复杂组合的关系。
The crude basalt walls in the Isortoq complex in central West Greenland have been subjected to the metamorphism of the amphibolite facies to the pomegranate granulite facies. Detailed sampling and petrology of these dikes indicate that complete assemblage can occur in a single dyke, amphibolite assemblages are usually limited to the margin of the dyke wall, and pomegranate-granulite facies rocks are present at the core of the dyke Department, pyroxene granulite phase between the former two. Electron microprobe analysis of all coexisting phases showed that the combination of amphibolite facies to granulite facies led to the separation of the amphibole and the cremal components from hornblende roughly in a 2: 1 ratio. Due to the appearance of the new phase after the reaction, the elemental abundance changed systematically with the disintegration of amphibole. In addition to the systematic variation of components in the dyke, a small amount of algebraic variation allows for the derivation of six balances that provide a general pattern of metamorphic rock metamorphism under advanced metamorphism that takes the form of a perfect combination of sequences , The ideal combination sequence will be based on X_ (H_2O), temperature and / or the pressure of the solid (region) gradient is expressed. These equilibrium analyzes show that different silica activity and Fe ~ (2 +) - Mg ~ (2+) exchange will change the stoichiometry of the reaction, which will affect the dissolution of amphibole and The proportion of the Cherkmark, but also the resulting plagioclase composition. These variables, together with changes in waterfluidness, will locally alter the sequence of the ideal combination and will explain the complex combination of relationships observed in the metamorphic rocks of the natural high zone.