Calibration and Application of a Ti-in-Quartz Geothermometer

该奖项将支持基于石英中钛含量的地温计的开发和应用。温度计将通过在一系列压力和温度条件下平衡石英与金红石和流体来校准。该温度计的应用将通过使用它来表征选定的火成岩和变质岩的热历史来进行测试。虽然校准假设TiO2活性为1，但如果可以通过其他方法估计Ti活性，则可以修改该校准以适用于缺乏纯TiO2相的系统。由于石英是地壳中最丰富的矿物之一，这种温度计——其精度比目前应用的大多数地温计大约好一个数量级——有望为许多岩石类型的热历史提供新的线索。当温度计与阴极发光强度成像相结合时，它应该被证明是特别强大的，阴极发光强度成像经常揭示生长历史的详细记录，并且似乎与石英的钛含量密切相关。

This award will support the development and application of a geothermometer based on the titanium-content of quartz. The thermometer will be calibrated by equilibrating quartz with rutile and fluid at a range of pressure and temperature conditions. Application of the thermometer will be tested by using it to characterize the thermal history of selected igneous and metamorphic rocks. Although the calibration assumes a TiO2 activity of one, it can be modified to apply to systems lacking a pure TiO2 phase if Ti activity can be estimated by some other means. Because quartz is one of the most abundant minerals in Earth's crust, this thermometer - which has a precision roughly an order of magnitude better than that of most geothermometers in application today - promises to shed new light on the thermal histories of many rock types. The thermometer should prove especially powerful when combined with imaging of cathodoluminescence intensity, which often reveals a detailed record of growth history, and which appears to be strongly correlated with the Ti content of quartz.