Kinetics of Metamorhpic Processes in the Contact Aureoles of Basalt Feeder Dikes, Killala Bay, Ireland

基拉拉湾玄武岩岩脉在石灰岩中的侵位，在小型(1.5米和5.3米)岩脉的光环中和一条50米长的岩脉的外部光环中产生了含有粗粒和硅灰石的组合，内环有非常高的温度组合，接触处有同化的石灰岩。对这些极光的热历史进行数值模拟，使它们可以作为自然实验，从中恢复方解石、硅灰石和石英粗化的动力学参数。将利用地层学、矿物组合和成分以及缓冲组合的热化学和反应进度计算来确定金矿中的压力、温度、流体成分和流体/岩石比，从而可以校准包括多期馈源流动、岩浆结晶和冷却的数值热史模型。测量的颗粒尺寸分布将用于区分Ostwald熟化和正常颗粒生长的粗化机制，平均颗粒尺寸随接触距离的变化将用于提取颗粒生长的材料常数和激活能。这项工作将在未来的研究中为分析硅灰石的动力学和石英位错的粗粒形核和退火而“校准”自然实验室。

Emplacement of basaltic feeder dikes in limestone at Killala Bay produced grossular- and wollastonite-bearing assemblage in the aureoles of small (1.5 and 5.3m) dikes and in the outer aureole of a 50m dike, which has very high temperature assemblages in its inner aureole and which has assimilated limestone along its contact. Numerical modelling of the thermal histories of these aureoles allows them to be used as natural experiments from which kinetic parameters for the coarsening of calcite, wollastonite and quartz can be recovered. Pressure, temperature, fluid composition and fluid/rock ratio in the aureoles will be determined using stratigraphy, mineral assemblages and compositions, and thermochemical and reaction-progress calculations for buffer assemblages so that a numerical thermal history model involving multiple episodes of feeder flow, magmatic crystallization and cooling can be calibrated. Measured grain-size distributions will be use to distinguish the coarsening mechanisms of Ostwald ripening and normal grain growth, and the variation of the mean grain size with distance from the contact will be used to retrieve material constants and activation energies for grain growth. This work will "calibrate" the natural laboratory for the analysis of the kinetics of wollastonite and grossular nucleation and annealing of quartz dislocations in future studies.