Toward a Constrained Hydrodynamic Model of Contact Metamorphism

9805102 纳贝莱克 PI将在犹他州的钙硅酸盐Notch Peak光环中进行接触变质的数值研究，以更好地了解控制接触光环中热演化和流体流动的流体动力学参数。它们将以目前可用的关于反应流体流动的岩石学和地球化学参数为基础，这些参数反映在矿物组合和地球化学的光环上。参数包括：（1）岩浆、变质和地层流体来源的收支，（2）岩石控制的分层的晕渗透结构，（3）瞬态孔隙，包括由变质岩中的破裂和体积变化引起的孔隙，（4）瞬态热场，（5）岩浆结晶潜热，（6）变质反应和流体加热的热量消耗，（7）岩体及其晕的观测几何形态。数值模拟将受到以前的岩石学和地球化学结果的流体流动的整体光环和详细的形态，矿物学和稳定同位素分析的露头。露头规模的数据将给出流动几何形状、孔隙度和渗透率类型以及单个岩层规模的流体通量的指示。除了更好地了解Notch峰的光环，结果将是一个重大贡献的知识变质作用，因为要调查的参数是基本的流体流动与所有接触光环。

9805102 Nabelek The PI will conduct a numerical study of contact metamorphism in the calc-silicate Notch Peak aureole, Utah, to obtain better understanding of hydrodynamic parameters that control thermal evolution and fluid flow in contact aureoles. They will build on currently available petrologic and geochemical parameters on flow of reactive fluids as reflected by mineral assemblages and geochemistry of the aureole. The parameters include: (1) budget of magmatic, metamorphic and formation fluid sources, (2) layered, lithologically controlled permeability structure of the aureole, (3) transient porosities, including those resulting from fracturing and volume changes in metamorphic rocks, (4) transient thermal field, (5) latent heat of crystallization of magma, (6) consumption of heat by metamorphic reactions and heating of fluids, and (7) observed geometry of the intrusion and its aureole. Numerical simulations will be constrained by previous petrologic and geochemical results on fluid flow in the overall aureole and by detailed morphologic, mineralogic, and stable isotope analyses of outcrops. The outcrop-scale data will give indications of flow geometry, type of porosity and permeability, and fluid flux on scale of individual beds. Besides a better understanding of the Notch Peak aureole, the results will be a significant contribution to the knowledge of metamorphism, because the parameters to be investigated are fundamental to fluid flow associated with all contact aureoles.