Toward a Constrained Hydrodynamic Model of Contact Metamorphism

PI将在犹他州的钙硅酸盐缺口峰光环中进行接触变质作用的数值研究。为了更好地理解控制接触光圈中热演化和流体流动的流体动力学参数。它们将以矿物组合和光晕地球化学所反映的反应流体流动的现有岩石学和地球化学参数为基础。参数包括：(1)岩浆、变质和地层流体来源的平衡；(2)光圈的层状、岩性控制的渗透率结构；(3)瞬态孔隙度，包括变质岩中压裂和体积变化产生的孔隙度；(4)瞬态热场；(5)岩浆结晶潜热；(6)变质反应和流体加热消耗的热量；(7)观察到的侵入体及其光圈几何形状。数值模拟将受到整个光晕中流体流动的岩石学和地球化学结果以及露头的详细形态、矿物学和稳定同位素分析的限制。露头尺度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层尺度上的流体通量的指示。除了更好地了解Notch峰光环外，研究结果将对变质作用的认识做出重大贡献，因为所研究的参数是与所有接触光环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.