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

火山与岩体的联系：内华达州科罗拉多延伸走廊流纹岩和花岗岩晶体群的记录

• 批准号: 0711109
• 负责人: Alfred Anderson
• 金额: $ 20.18万
• 依托单位: University of Chicago
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-08-01 至 2012-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0711109&HistoricalAwards=false
• 关键词: Volcano; Pluton; Connections; Record; Crystal

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.

知识价值。硅质火山系统和深成系统之间的关系是岩石学中一个非常有趣的问题。浅层地壳岩浆储层很重要，因为它们是岩浆储存和分异的场所，它们通常与矿床有关，而且，对这一建议特别重要的是，这些系统之间的关系可能为岩浆和喷发过程提供重要的见解。最近在一些流纹岩中发现了火山喷发的似是而非的纹理指纹，类似的火山喷发标志很可能也保存在深成花岗岩中。目前的项目关注的是：(1)能否在深成岩的晶体中发现火山喷发的指纹？(2)这些指纹能否与伴生火山岩的指纹相对应？(3)根据这些深成岩记录，可以推断出一个体系的喷发历史。这些问题将通过研究花岗岩和流纹岩中貌似相关的晶体种群来解决(a)微量元素分区，(b)晶体尺寸分布，(c)熔体包裹体中记录的它们生长的熔体成分，以及(d)锆石晶体记录的结晶年龄。科罗拉多河伸展走廊（内华达）包括几个岩体和火山序列，其中火山和深部系统之间的联系已被记录在案。该地区倾斜的岩体和火山单元的特殊暴露将为探索火山和深成岩的组合记录提供一个独特的机会，从而更好地了解火山喷发以及深成和火山岩浆系统之间的关系。更广泛的影响。该项目将支持一名博士后、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伸展走廊工作了十多年的地质学家团队之间的合作。虽然主要是一个基础科学项目，但这项工作的结果将有助于了解火山系统的动力学和相关的火山危害。