Pre-eruptive conditions of the volcanic rocks from Snake River Plain, Yellowstone Hotspot-Constraints from experiments and phase equilibria modelling

计划在蛇河平原火山省（美国西部）进行的ICDP钻探旨在追踪。蛇河平原-黄石（SRPY）热点及其与岩石圈的相互作用。这个省代表了与大陆岩石圈内热点火山活动有关的热异常的最好例子之一。在过去的15 Ma中，srpyi热点向东移动了约600 km，导致双峰（流纹岩-玄武岩）岩浆活动。了解srpy -热点与岩石圈的相互作用，需要了解流纹岩和玄武岩岩浆的化学演化、来源、分异和储存条件随时间和空间的变化。该项目为确定srpy省的岩浆储存条件和分异过程做出了贡献。这些信息来自：(1)对天然矿物和玻璃的化学分析，结合(2)确定相平衡的高压实验研究和(3)热力学建模。在这个延续的提案中，我们报告了我们的初步结果（经过12个月的运行项目）对布鲁诺-贾比奇喷发中心（美洲狮点凝灰岩）流纹岩的结晶实验。我们的初步结果表明，流纹岩非常干燥，先发制人的温度低于之前的预测。利用热力学相平衡模型对两个地区（Boise River和Kimama Butte）玄武岩熔岩的岩浆储存条件和分化过程进行了约束。

The planed ICDP drilling in the Snake River Plain volcanic province (westem United States) is aimed to trace .the Snake River Plain - Yellowstone (SRPY) hotspot and its interaction with the lithosphere. This province represents one of the best examples of a thermal anomaly related to hotspot volcanism within the continental lithosphere. Over the last 15 Ma, the SRPY-hotspot migrated ca. 600 km eastwards resulting in a bimodal (rhyoliticbasaltic) magmatism. Understanding the interaction ofthe SRPY-hotspot with the lithosphere requires information on the evolution of chemistry, sources, differentiation and storage conditions of both the rhyolitic and basaltic magmas with time and space. The proposed project is a contribution to the determination of magma storage conditions and differentiation processes in the SRPY-province. This information is gained (1) from the chemical analysis of natural minerals and glasses combined with (2) high pressure experimental studies to determine phase equilibria and (3) thermodynamic modeling. In this continuation proposal we report our preliminary results (after 12 months of the running project) on crystallization experiments with rhyolite from Bruneau-Jarbidge eruptive center (Cougar Point Tuff). Our preliminary results indicate the rhyolites were extremely dry and that pre-emptive temperatures were lower than previously suggested. Magma storage conditions and differentiation processes of basaltic lavas from two localities (Boise River and Kimama Butte) will be constrained using thermodynamic phase equilibria models.