【作者】 程黎鹿；

【导师】 罗照华；

【作者基本信息】 中国地质大学（北京） ， 矿物学、岩石学、矿床学， 2014， 博士

【摘要】 按早期玄武岩→辉长岩→晚期酸性岩的时间顺序，探讨了峨眉山大火成岩省幔源岩浆在地壳运移，滞留和演化的过程。通过结合这些方法，可以全面认识岩浆过程中的五个主要变量即时间，空间，温度，压力和成分，从而更准确地揭示峨眉山大火成岩省中的岩浆作用的化学过程和物理过程。论文取得以下主要的成果和认识：基于前人提出的地幔熔融柱模型和反演方法笔者编写了一个界面友好的应用软件Calmantle1.0。应用Calmantle1.0，用户可轻易获得玄武岩部分熔融源区的起止条件包括温度，压力，深度和部分熔融程度。将大桥剖面出露的斜长石巨晶玄武岩细分为离散型（SI型）和聚集型（CT型）。两种斜长石巨晶玄武岩全岩成分上都显示出低MgO，高Ti和高FeO特征。两类斜长石巨晶在定量化结构图上都表现出S型CSD特征，但是存在明显不同的特征长度。假设斜长石巨晶的生长速率为10-11-10-10mm/s,那么CT型和SI型的斜长石巨晶的生长时间分别为500–6,000年和1,000–10,000年。我们给出一个新的再活化基质，即流体的注入导致岩浆黏度的急剧下降从而使得滞留岩浆再活化并且快速喷出。Sr-Nd-Pb相关图解指示峨眉山低Mg斜长石巨晶玄武岩靠近EMI区域。攀枝花铁矿区斜长石巨晶辉长岩以岩墙形式侵入到了其底带的细粒辉长岩。斜长石巨晶从核部到边部的原位Sr同位素成分剖面较为稳定，表明斜长石巨晶不是循环晶。斜长石巨晶辉长岩在CSD图解上呈线性，取斜长石巨晶的生长速率为10-11-10-10mm/s,那么其生长时间为530-8118年。假设对于100km3岩浆房，以1000MW的功率散热,达到50%晶体含量，辉长岩体需要～2400年。巨晶生长时间和数值模拟约束攀枝花侵入体的侵位时间和冷却时间发生在千年尺度。通过对大老包黑云母二长花岗岩的锆石LA-ICP-MSU-Pb年龄测定，获得大老包花岗岩形成时代为257.1±1.7Ma。基于下地壳热区模型进行数值模拟结果，认为大老包花岗岩可能是峨眉山大火成岩省中底侵的玄武质岩浆在3Ma内部分熔融下地壳形成的。更多还原

【Abstract】 Based on the field work, quantitative textural analysis theory and geochemistry, we studied the magma transfer, storage and evolution by studying basalts, grabbros and granites in Emeishan large igneous province(LIP) in this PhD dissertation. Using these methods, we kwon the five basic variables of time, space, temperature, pressure and composition, and as far as seeks to clarify the magma chemical and physical process. The dissertation made several major achievements and insights as follows:Based on the proposed previously mantle melting column model and its inversion method, we have designed an implication software Calmantle1.0with friend interfaces. Using this software, users can easily obtain the partial melting conditions at the initial and final stages, including temperature, pressure, depth, the degree of partial melting and so on.We report a quantitative textural analysis and bulk-rock geochemical composition of clustered touching crystals (CT-type) and single isolated crystal (SI-type) GPB samples in the Daqiao section. Both types of GPBs are evolved, but have high Ti/Y ratiosand high total FeO content. The two types of GPBs have S-type crystal size distributions but have quite different characteristic lengths. For plagioclase growth rates of10-11to10-10mm/s, The plagioclase megacrysts have the residence time of about500-6,000years, about1,000-10,000years, respectively. We suggest that CT-and SI-type crystals grew and were coarsened in the outer part and inner part of a magma chamber, respectively. Magma evolution during storage is controlled by crystallization, crystal growth, and magma mixing, and pulsating eruptions occur in response to the continuous supply of hot magma and fluid intrusions. The isotopic compositions show they are from EM I.The giant plagioclase gabbros (GPG) dykes mostly intrude into the fine-grained gabbros without significant contact. However, the mineral composition results show that most of the plagioclase megacrysts contain less An than do plagioclase in fine-grained gabbro samples. In situ analyses of Sr isotopes from core-to-rim transects of plagioclase megacrysts are constant, indicating there are no recycling crystals. For a plagioclase growth range of10-11-10-10mm/s, the plagioclase should have a growth time of530-8118years. In a100km3magma chamber releasing thermal energy at a rate of1000MW, Panzhihua intrusion should reach50%crystallization after -2400years. The growth time recorded by the megacrysts in GPG and numerical modelling may constrain the emplacement timescales of Panzhihua intrusion may take place on thousands of years.The Hongge Dalaobao granitic stock in the Emeishan large igneous province, SW China. In situ ziron LA-ICP-MS U-Pb age indicates that the age of monzogranite is257.1±1.7Ma. Based on the deep crustal hot zones, the results of numerical simulation show that the partial melting of deep crust and the Dalaobao granites magmatism are triggered by conductive heating of the mantle-driven magma within3Ma.更多还原