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

黄石热点蛇河平原火山岩喷发前条件实验和相平衡模型的约束

• 批准号: 37025833
• 负责人: Professor Dr. Francois Holtz, Ph.D.
• 金额: --
• 依托单位: Institut für Mineralogie
• 依托单位国家: 德国
• 项目类别: Infrastructure Priority Programmes
• 财政年份: 2007
• 资助国家: 德国
• 起止时间: 2006-12-31 至 2011-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/37025833?language=en
• 关键词: Pre; eruptive; conditions; volcanic; rocks

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.

计划在斯内克河平原火山省（美国西部）进行的 ICDP 钻探旨在追踪斯内克河平原 - 黄石 (SRPY) 热点及其与岩石圈的相互作用。该省是大陆岩石圈内与热点火山活动相关的热异常的最佳例子之一。在过去 15 Ma 中，SRPY 热点迁移了约 100 万次。向东 600 公里处形成双峰式（流纹玄武岩）岩浆作用。了解 SRPY 热点与岩石圈的相互作用需要有关流纹岩浆和玄武质岩浆随时间和空间的化学演化、来源、分化和储存条件的信息。拟议项目有助于确定 SRPY 省的岩浆储存条件和分异过程。该信息是通过 (1) 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) 热力学模型获得的。在这份延续提案中，我们报告了对来自 Bruneau-Jarbidge 喷发中心（Cougar Point Tuff）的流纹岩进行结晶实验的初步结果（项目运行 12 个月后）。我们的初步结果表明，流纹岩极其干燥，预先设定的温度低于之前建议的温度。来自两个地点（博伊西河和 Kimama Butte）的玄武岩熔岩的岩浆储存条件和分化过程将使用热力学相平衡模型进行约束。