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

Evans0000904该项目的主要目标是重新校准铁钛氧化物温度计，以适应中间到硅质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，通过在受控的 T（700-900 摄氏度）、P 和 O2（NNO 1 至 NNO 3）条件下对掺杂有大量但不同数量的 FeO、TiO2 和 MgO 的合成流纹岩组合物进行水热平衡。这些实验将确定共存的铁钛铁矿和钛磁铁矿（含或不含 Mg）对所讨论范围内的 T 和 O2 的成分依赖性。 需要正确地将硅镁石溶液容纳到菱形 Fe-Ti 氧化物中的溶液参数来适应这些实验。 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.