Testing Models of Crustal-Scale Fluid Flow and Isograd Development During Orogenesis in the Barrovian Zones, Scotland

苏格兰巴罗维亚地区造山作用期间地壳规模流体流动和等梯度发育的测试模型

• 批准号: 0509934
• 负责人: Jay Ague
• 金额: --
• 依托单位: Yale University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-06-01 至 2012-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0509934&HistoricalAwards=false
• 关键词: Testing; Models; Crustal; Scale; Fluid

Fluids produced during the heating of metamorphic rocks impact a broad array of geologic processes, including the evolution of the atmosphere and its greenhouse gas content; the formation of ore deposits; the transport of heat; the generation of magmas and volcanic activity; and the production of faults and seismicity. Proper understanding of these and other fluid-driven processes, however, requires a regional-scale understanding of fluid circulation patterns through the crust at depths in excess of 15 km below the surface during mountain-building events. Barrovian-style metamorphism is the most common type recognized worldwide and, as such, is a basic model for understanding metamorphic processes as well as the geochemical and geophysical impacts of fluids comprising water, carbon dioxide, dissolved solutes, and other constituents. The proposed work focuses on the Barrovian type locality of Scotland, and will use the elemental and isotopic mass transfer recorded in the rocks together with numerical models constrained by field- and laboratory-based initial and boundary conditions to test hypotheses of fluid flow, heat transport, and magma formation during metamorphism. Three field areas spanning the crustal depth range of ~15 to ~35 km will be examined, with a particular focus on the Highland Boundary Fault. This crustal-scale structure extends ~250 km across Scotland and is clearly a fundamental control on the spatial distribution of metamorphic rock types in the Barrovian sequence. Nonetheless, despite over a century of study, its role in the geochemical and tectonic evolution of earth's crust during the global-scale, Caledonian-Appalachian mountain building episode remains controversial and poorly resolved. Human resources will be developed because field- and laboratory-based Ph.D. graduate student as well as undergraduate B.S. thesis research is critical to the project. PI Ague is leading a complete renovation of the rock and mineral section of the Yale Peabody Museum, and this will allow integration of new research results into Earth science displays viewed by over 150,000 visitors annually. A large fraction of these visitors are schoolchildren, many of whom live in the urban centers of New Haven, Bridgeport, and other Connecticut cities. The exhibition would be the only one of its kind in Connecticut or Rhode Island and, as such, serve as a critical regional scientific and educational resource for the Museum's diverse audiences. A series of books and accompanying CDs/DVDs on Earth Science for K-6 grade students and an interactive web site will be produced to coincide with the exhibition; the project will support production of one of the books.

在变质岩加热过程中产生的流体影响了广泛的地质过程，包括大气及其温室气体含量的演变;矿床的形成;热量的传输;岩浆和火山活动的产生;以及断层和地震活动的产生。然而，要正确理解这些和其他流体驱动的过程，就需要在区域范围内了解造山活动期间地表以下15公里以上深处地壳中的流体循环模式。巴罗式变质作用是世界范围内公认的最常见的类型，因此，它是理解变质过程以及包括水、二氧化碳、溶解溶质和其他成分的流体的地球化学和地球物理影响的基本模型。拟议的工作重点在苏格兰的Barrovian型地方，并将使用记录在岩石中的元素和同位素质量转移与数值模型约束的现场和实验室为基础的初始和边界条件，以测试假设的流体流动，热传输，和岩浆形成变质作用。将对地壳深度范围为~15至~35 km的三个野外区域进行检查，特别关注高地边界断层。这种地壳规模的结构延伸约250公里，横跨苏格兰，显然是一个基本控制的空间分布的变质岩石类型的巴罗序列。尽管如此，尽管经过了世纪的研究，它在全球尺度的加里东-阿巴拉契亚山脉建造事件中地壳的地球化学和构造演化中的作用仍然存在争议，而且解决得很差。人力资源将得到开发，因为实地和实验室为基础的博士学位。研究生和本科生都有学士学位。论文研究对这个项目至关重要。PI Ague正在领导耶鲁皮博迪博物馆岩石和矿物部分的全面翻新，这将使新的研究成果融入地球科学展览，每年有超过15万名游客观看。这些游客中有很大一部分是学童，其中许多人住在纽黑文、布里奇波特和康涅狄格州其他城市的市中心。该展览将是康涅狄格州或罗得岛唯一的同类展览，因此，它将成为博物馆不同观众的重要区域科学和教育资源。为配合展览，将为K-6年级学生制作一系列关于地球科学的书籍和随附的CD/DVD，并制作一个互动网站;该项目将支助其中一本书的制作。