Exsolution in titanomagnetites as an indicator of cooling rates
Exsolution in titanomagnetites as an indicator of cooling rates
复制标题
钛磁铁矿中的溶出作为冷却速率的指标
作者：
G. D. Price
摘要：一些钛磁铁矿中所发育的出溶结构的规模和性质已被用于计算氧化物在出溶时的冷却速率。通过评估一个动力学模型来计算冷却速率，该模型描述了在出溶过程中钛磁铁矿中富钛铁晶石片晶的生长。通过数值技术和一种近似解析方法对该模型进行了评估。计算得出，塔贝格、斯凯尔加德以及部分亚马斯卡山侵入体在钛磁铁矿出溶期间的冷却速率分别约为每1000年130℃、12℃和6000℃。这些数值与根据侵入体热流模型计算出的冷却速率非常吻合。
Abstract The scale and nature of the exsolution textures developed in some titanomagnetites have been used to calculate the rate at which the oxides were cooling at the time of exsolution. The cooling rates were calculated by evaluating a kinetic model, which describes the growth of an ulvöspinel-rich lamella in titanomagnetite during exsolution. The model was evaluated both by numerical techniques and by an approximate analytical method. The cooling rates during titanomagnetite exsolution of the Taberg, Skaergaard and part of the Mt. Yamaska intrusions were calculated to be approximately 130, 12 and 6000°C per 1000 years respectively. These values are in good agreement with cooling rates calculated from heat flow models of the intrusions.