Volcano-Pluton Connections: The Record in Crystal Populations of Rhyolites and Granites of the Colorado Extensional Corridor, Nevada

智力上的优点。硅质火山岩和深成岩系之间的关系是岩石学中非常感兴趣的问题。地壳浅层岩浆储集层很重要，因为它们是岩浆储存和分异的场所，它们通常与矿床有关，而对这一提议特别重要的是，这些系统之间的关系可能为岩浆和喷发过程提供重要的洞察。最近在一些流纹岩中发现了喷发的可信结构指纹，很可能类似的喷发标志将被保存在深成花岗岩中。目前的项目涉及：(1)在深成岩的晶体中能找到喷发的指纹吗？(2)这些指纹能与伴生的火山岩中的指纹相关联吗？(3)根据这一深成记录，可以对一个系统的喷发历史做出什么推断？这些问题将通过研究看似相关的花岗岩和流纹岩中的晶体群体来解决，这些问题包括(A)微量元素分带，(B)晶体大小分布，(C)熔体成分，如熔体包裹体中所记录的，以及(D)锆石晶体记录的结晶年龄。科罗拉多河延伸走廊(内华达州)包括几个深成岩和火山序列，在那里火山系统和深成岩系统之间的联系已被记录在案。在这个倾斜的深成岩和火山单元区域的特殊暴露将提供一个独特的机会来探索火山和深成岩的综合记录，从而更好地了解喷发以及深成和火山岩浆系统之间的关系。该项目(按提议)将支持一名博士后、一名研究生和一名或多名本科生。这项研究还将涉及PI和一个在科罗拉多河延伸走廊工作了十多年的地质学家团队之间的合作。虽然这主要是一个基础科学项目，但这项工作的结果将与理解火山系统的动力学和相关的火山灾害有关。

Intellectual merit. The relationship between silicic volcanic and plutonic systems is a matter of great interest in petrology. Shallow crustal magma reservoirs are important because they are sites of magma storage and differentiation, they are commonly associated with ore deposits, and, what is especially significant to this proposal, the relations between such systems may provide important insights into magmatic and eruptive processes. Plausible textural fingerprints of eruptions have recently been recognized in some rhyolites and it is likely that similar markers of eruptions will be preserved in plutonic granites. The current project concerns: (1) Can fingerprints of eruptions be found in crystals of plutonic rocks? (2) Can these fingerprints be correlated with those in associated volcanic rocks? (3) What can be inferred about the eruption history of a system based on this plutonic record?These questions will be addressed by studying crystal populations in plausibly correlated granites and rhyolites in terms of (a) trace-element zoning, (b) crystal size distributions, (c) the compositions of melts from which they grew, as recorded in melt inclusions, and (d) the ages of crystallization recorded by zircon crystals. The Colorado River Extensional Corridor (Nevada) includes several plutons and volcanic sequences where links between volcanic and plutonic systems have been documented. The exceptional exposures in this area of tilted plutons and volcanic units will provide a unique opportunity to explore the combined record in volcanic and plutonic rocks towards a better understanding of eruptions and the relationships between plutonic and volcanic magma systems.Broader impacts.This project (as proposed) would support a post-doctoral associate, a graduate student, and one or more undergraduate students. This study will also involve collaboration between the PI and a team of geologists working in the Colorado River Extensional Corridor for more than a decade. Although principally a basic science project, The results of this work would be relevant to understanding the dynamics of volcanic systems and related volcanic hazards.