Towards timescales of assimilation and magma mixing in the Large Igneous Province of Snake River Plain-Yellowstone, northwest United States

美国西北部蛇河平原-黄石大火成岩省同化和岩浆混合的时间尺度

• 批准号: 132239063
• 负责人: Professor Dr. Donald Bruce Dingwell
• 金额: --
• 依托单位: Lehrstuhl für Mineralogie und Petrologie
• 依托单位国家: 德国
• 项目类别: Infrastructure Priority Programmes
• 财政年份: 2009
• 资助国家: 德国
• 起止时间: 2008-12-31 至 2013-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/132239063?language=en
• 关键词: Towards; timescales; assimilation; magma; mixing

The breath of magma diversities in the Snake River Plain and Yellowstone (SRP-Y) volcanic fields presents a unique opportunity to study the interaction of a hot-spot-related thermal anomaly with the continental crust and the subsequent development of magma reservoirs. As a reservoir forms, primitive magma batches induce crustal melting and assimilation, and mixing. Mixing caused by a recharge of a more primitive magma is expected to be accompanied by heating of the reservoir which may obstruct fractionation and thus to precede it. The SRP-Y holds the tale of this chemical process and therefore provides the pieces of the puzzle portraying the evolution of magmas. A series of tests is proposed to systematically characterize the evolution and importance of mixing during the lifetime of reservoirs fed by a hotspot. This work aims to (1) identify end members in the SRP, and (2) to characterize their physical (e.g., density, viscosity) and chemical (e.g., interstitial melt’s composition, volatile content) properties. In a second phase, this work will (3) assess the interaction between physical and chemical properties of the magmas involved in the SRP-Y systems; and (4) constrain changes in the timescale of assimilation and mingling in the SRP magma reservoirs.

蛇河平原和黄石（SRP-Y）火山场岩浆多样性的呼吸为研究热点相关热异常与大陆地壳的相互作用以及岩浆储层的后续发育提供了独特的机会。在储层形成过程中，原始岩浆会引起地壳的熔化、同化和混合。由更原始岩浆的补充引起的混合，预计会伴随着储层的加热，这可能会阻碍分馏，从而在分馏之前发生。SRP-Y掌握着这一化学过程的故事，因此提供了描绘岩浆演化的拼图。提出了一系列试验，以系统地表征由热点补给的储层在生命周期内的混合演化及其重要性。这项工作的目的是(1)确定SRP中的末端成员，(2)表征它们的物理（例如，密度，粘度）和化学（例如，间隙熔体的组成，挥发性含量）特性。在第二阶段，这项工作将(3)评估SRP-Y系统中涉及的岩浆的物理和化学性质之间的相互作用；(4)约束了SRP岩浆储层中同化和混合作用的时间尺度变化。