Processes of Metasomatism in Plutonic Rocks

大型层状侵入体的某些特征表明， 渗透驱动的交代反应或其他后 固化过程在以下方面发挥了核心作用： 影响矿物和化学物质的最终分布 件. 最近在《世界卫生组织 Skaergaard入侵，包括： a. 长英质岩石中似结核的镁铁质矿物块 矩阵; B. 早期岩石形成的形状不规则的残余岛屿 在较长英质重结晶的区域内;以及 C. 富斜长石岩多指枝晶 更富含铁的基质中 最近也观察到这种现象。 水-岩反应/输运方程模拟 系统. 我们建议使用建模来解释这些的起源 再结晶现象，并预测其他可能的后， 凝固转变 应说明的进程 这些模拟包括晶粒生长和溶解、溶质 扩散和渗透输运、流体流动和压力 溶液 因为我们的模型显示这些现象 在明确定义的条件下，我们将使用 解释Skaergaard中常见特征的模型 和其他大型层状侵入体

Certain features in large layered intrusions suggest that infiltration-driven metasomatic reactions or other post- solidification processes have played a central role in influencing the final distribution of mineral and chemical components. Features of this kind, recently recognized in the Skaergaard Intrusion, include: a. concretion-like masses of mafic minerals in a felsic matrix; b. irregularly shaped residual islands of earlier rock within a more felsic recrystallized domain; and c. multiply-fingered dendrites of plagioclase-rich rock within a more iron-rich matrix. Phenomena of this kind have also been observed in recent simulations of the reaction/transport equations for water-rock systems. We propose to use modeling to explain the origins of these recrystallization phenomena and to predict other possible post- solidification transformations. Processes to be accounted for in these simulations include grain growth and dissolution, solute diffusion and infiltration transport, fluid flow, and pressure solution. Because our models show that these phenomena occur under well-defined conditions, we shall use the results of the models to interpret commonly observed features in the Skaergaard and other large layered intrusions.