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，以适应中间到硅基成分喷发的实际条件。拟议的实验工作将在法国奥尔良的CNRS实验室进行，方法是在受控的T(700-900摄氏度)、P和O2(NNO 1至NNO 3)条件下，通过水热平衡合成的流纹岩成分，掺入大量但可变数量的FeO、TiO2和MgO。这些实验将确定共存的铁钛铁矿和钛磁铁矿，在有和没有镁的情况下，在所讨论的范围内对T和O2的成分依赖。为了适应这些实验，需要合适的溶液参数来适应三方铁钛氧化物中的硅铝榴石溶液。这项实验工作的结果应该有助于增加这种流行的地质温度计对以前超出适当成分范围的岩石的适用性。

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.