Toward a Constrained Hydrodynamic Model of Contact Metamorphism

9805102纳布勒克PI将对钙硅酸盐缺口峰晕接触变质作用进行数值研究，为了更好地了解控制接触极光中的热演化和流体流动的流体动力学参数。它们将建立在目前可用的岩石学和地球化学参数的基础上，这些参数基于反应流体的流动，如矿物质组合和光环的地球化学所反映的。这些参数包括：(1)岩浆、变质和地层流体来源的平衡，(2)光环的层状、岩性控制的渗透性结构，(3)瞬变孔隙度，包括变质岩中破裂和体积变化产生的孔隙度，(4)瞬变热场，(5)岩浆结晶潜热，(6)变质反应和流体加热消耗的热，(7)观察到的侵入体及其光环的几何形状。数值模拟将受到之前岩石学和地球化学结果的限制，这些结果涉及整个光环中的流体流动，以及露头的详细形态、矿物学和稳定同位素分析。露头尺度的数据将给出流动几何形状、孔隙度和渗透率的类型以及各层尺度上的流体流量的指示。除了更好地了解缺口峰晕，这些结果将是对变质作用知识的重大贡献，因为要研究的参数是与所有接触晕相关的流体流动的基础。

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.