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地球化学分析方法已广泛运用于火成岩成因的研究中,但对于一些蚀变较严重的岩石,有时仅通过地球化学分析难以还原岩浆固结的过程。火成岩定量化结构分析方法是通过对岩石中矿物的定量分析(诸如晶体粒度分布分析,晶体空间分布分析,以及晶体定向程度分析等),从而反演岩浆固结过程中发生的动力学过程。这种方法很好地避免了蚀变作用对还原岩体形成过程所产生的诸多影响。本文运用火成岩定量化结构分析方法,对新疆莫阿特茂金花岗斑岩体钻孔中10个样品的钾长石斑晶和石英斑晶分别进行分析。尽管这些样品普遍发生了碳酸盐化蚀变作用,定性观察中结构特征也比较均一,但是钾长石和石英斑晶的定量化结构数据及其在钻孔深度(约170 m)范围内的变化趋势显示,茂金花岗斑岩体可能至少由4次脉冲岩浆叠加形成,每股岩浆中心的CSD曲线小晶体缺乏,发生了粗化现象。由于脉冲式岩浆多次注入,导致的温度振荡加剧了矿物粗化。脉冲岩浆中心处斑晶体积含量的增加,可能与岩浆流动过程中对大晶体的影响有关,80 m深度以下脉冲岩浆接触带的斑晶体积含量明显增加,是由于机械压缩导致的。
Geochemical analysis methods have been widely used in the study of igneous genesis. However, for some rocks with more serious alteration, it is sometimes difficult to reduce the consolidation process of magma only by geochemical analysis. Quantitative structural analysis of igneous rocks is based on the quantitative analysis of minerals in the rock (such as the analysis of crystal size distribution, the analysis of crystal spatial distribution, and the degree of crystal orientation analysis), so as to invert the dynamic process occurring in the process of magma consolidation. This method well avoids many effects of alteration on the formation of reduced rock mass. In this paper, the quantitative analysis of igneous rocks is used to analyze the K-feldspar phenocrysts and quartz porphyrites in 10 samples from the drilling of the Moat metallocene porphyry in Xinjiang Autonomous Region. Despite the widespread carbonate alteration in these samples and the structural characterization in qualitative observations, the quantitative structure data of K-feldspar and quartz porphyrite and their changes in borehole depth (~ 170 m) The trend shows that the metallocene granitic porphyry may be formed by the superimposition of at least four pulsed magmas, and the CSD curve of each magma center lacks crystals and coarsening occurs. Due to the pulsed magma multiple infusions, the resulting temperature oscillations exacerbate mineral coarsening. The increase of the content of the plaque in the pulsed magma center may be related to the influence of large crystals during the magma flow. The volume of the porphyrin in the contact zone of the pulsed magma below 80 m is obviously increased due to the mechanical compression.