A Two-stage Thermal Evolution Model of Magmas in Continental Crust
A Two-stage Thermal Evolution Model of Magmas in Continental Crust
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陆壳岩浆两阶段热演化模型
DOI：
10.1093/petroj/40.2.241
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发表时间：
1999
影响因子：
3.9
通讯作者：
K. Kaneko
中科院分区：
文献类型：
--
作者：
T. Koyaguchi;K. Kaneko
当玄武岩浆侵位于大陆地壳中时，地壳熔融产生玄武岩浆。当岩浆侵位到大陆地壳中时，它是岩浆形成一个单独的岩浆层，几乎没有化学反应，被认为是储存在一个“岩浆房”中，在一定程度上与下面的致密玄武岩浆层。广泛的融化期。大量的研究揭示了玄武岩作为热源时，岩浆与地壳交界处的岩石学特征和岩浆的地球化学特征。岩浆房中物质和热量的传递过程，如岩浆与地壳边界的结晶作用，控制着岩浆的形成、地壳物质的熔融和岩浆热演化的混合作用。岩浆的热演化（如McBirney，1980; Huppert & Turner，1981;将玄武岩侵位后的岩浆分为两个Sparks等，1984; Koyaguchi & Blake，1991）。这篇论文的阶段。在第一阶段，岩浆中的温度上升，讨论了岩石学过程，如同化以上，然后衰减到地壳的熔融温度和分离结晶影响的热演化在短时间尺度上（10年）。流体动力学和岩浆在岩浆房中停留时间的实验结果表明，岩浆在陆壳中的位置一般较低。由于结晶分离作用，熔融温度比地壳高，提出了第一阶段中部分熔体的停留时间和混合作用以及陆壳中岩浆房在第一阶段末有效液态的一些探索性模型。在第二阶段，基于热质传递的物理学原理，岩浆在更长的时间内通过热传导缓慢冷却（Spera，1979; Huppert & Sparks，1988 a; Marsh，1989）。时间表（10年）。第二阶段岩浆的岩石学特征受Huppert & Sparks（1988 a）模型的岩石学特征的强烈制约，在该模型中，周围的地壳以及供给的岩浆本身的岩石学特征;其在室顶部温度下的结晶和熔化的物理性质保持在或略低于室顶部温度的熔化温度，对流在岩浆地壳中存在很长一段时间，因为冷却速度慢;其斑晶被考虑在内。根据他们的模型，a含量反映了岩浆熔融分数与温度的差异，侵入大陆地壳的玄武岩导致岩浆与地壳之间的广泛关系。从岩浆房顶板地壳物质的熔融到两个阶段之间明显的冷却速率来看，喷发的岩浆是一种岩浆热液。在温度统计上更可能反映岩浆的特征，在岩浆上升之上，然后衰减回到熔融的第二阶段。地壳的温度（一般来说，
When a basaltic magma is emplaced in a continental crust, a INTRODUCTION silicic magma is generated by melting of the crust. The light silicic When magma is emplaced into continental crust, it is magma forms a separate magma layer with little chemical interaction believed to be stored in a ‘magma chamber’ for a certain with the underlying dense basaltic magma layer. Extensive melting period. Extensive studies have revealed how petrological occurs at the boundary between the silicic magma and the crust and geochemical features of magmas are controlled by while the basalt acts a heat source. The mass and heat transfer at processes in magma chambers such as crystallization of the boundary between the silicic magma and the crust controls the magma, melting of crustal materials, and mixing of thermal evolution of the silicic magma. The thermal evolution of magmas (e.g. McBirney, 1980; Huppert & Turner, 1981; the silicic magma after the basalt emplacement is divided into two Sparks et al., 1984; Koyaguchi & Blake, 1991). This paper stages. In the first stage, the temperature in the silicic magma rises discusses how petrologic processes such as assimilation above and then decays back to the melting temperature of the crust and fractional crystallization affect the thermal evolution on a short timescale (10 years). The results of fluid dynamics and the residence times of magmas in magma chambers experiments suggest that the silicic magma generally has a lower in continental crust. melting temperature than the crust because of fractional crystallization Some exploratory models for the residence time of a and mixing of partial melts during the first stage, and that it can magma chamber in continental crust have been proposed be effectively liquid at the end of the first stage. In the second stage, on the basis of the physics of heat and mass transfer the silicic magma cools slowly by heat conduction on a much longer (Spera, 1979; Huppert & Sparks, 1988a; Marsh, 1989). timescale (10 years). Petrological features of the magma in the To formulate the present problem it is helpful to introduce second stage are strongly constrained by petrological features of the the model by Huppert & Sparks (1988a), in which the surrounding crust as well as those of the supplied magma itself; its physics of crystallization and melting at the chamber roof temperature remains at or just below the melting temperature of the as well as the effects of thermal convection in the magma crust for a long time because of the slow cooling rate; its phenocryst are taken into account. According to their model, a content reflects the difference in the melt fraction vs temperature basalt emplaced into continental crust results in extensive relationships between the magma and the crust. Judging from the melting of the crustal materials at the chamber roof to distinct cooling rate between the two stages, erupted magmas are form a silicic magma. The temperature in the silicic statistically more likely to reflect the characteristics of magmas in magma rises above and then decays back to the fusion the second stage. temperature of the crust (in general ‘the effective fusion