SGER: Calibration of FeTi-Oxide Thermobarometer at 700-900 Degrees Celsius and High Oxygen Fugacity

这个项目的主要目标是重新校准铁钛氧化物温度计，以适应中间到硅成分喷发的现实条件。实验工作将在法国奥尔良的CNRS实验室进行，在受控的温度（700-900摄氏度）、P和O2 （NNO+1至NNO+3）条件下，通过水热平衡合成流纹岩成分，使其掺杂大量但数量不同的FeO、TiO2和MgO。这些实验将建立共存铁钛铁矿和钛磁铁矿的组成依赖，有和没有Mg，对T和O2的范围内的问题。为了适应这些实验，将需要正确地容纳盖氏晶石溶液到菱面体铁钛氧化物中的溶液参数。这项实验工作的结果应该有助于提高这种流行的地温计对以前不在适当成分范围内的岩石的适用性。

Evans0000904This project has as a major goal, to recalibrate the Fe-Ti-oxide thermometer for realistic conditions of eruption of intermediate to silicic compositions. The experimental work proposed will be conducted in the CNRS laboratory in Orleans, France, by hydrothermally equilibrating a synthetic rhyolite composition doped with substantial but variable amounts of FeO, TiO2 and MgO at controlled T (700-900 degrees C), P, and O2 (NNO+1 to NNO+3) conditions. These experiments will establish the composition dependence of coexisting ferrian ilmenite and Ti-magnetite, with and without Mg, on T and O2 in the range in question. Solution parameters that correctly accomodate the solution of geikielite into the rhombohedral Fe-Ti oxide will be required to fit these experiments. The results of this experimental work should help increase the applicability of this popular geothermometer to rocks that were previously outside the appropriate compositional range.