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

变质岩加热过程中产生的流体影响一系列广泛的地质过程，包括大气的演化及其温室气体含量；矿床的形成；热量的输送；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由流体驱动的过程，就需要在区域范围内了解造山活动期间地表以下15公里以下的地壳中的流体循环模式。巴罗式变质作用是世界上公认的最常见的变质作用类型，因此是了解变质过程以及由水、二氧化碳、溶解溶质和其他成分组成的流体的地球化学和地球物理影响的基本模式。拟议的工作重点放在苏格兰的巴罗维亚类型，并将使用岩石中记录的元素和同位素质量转移，以及受现场和实验室初始和边界条件约束的数值模型，来测试变质过程中流体流动、热传输和岩浆形成的假说。将研究地壳深度范围为~15至~35公里的三个野外区域，重点是高地边界断层。这种地壳尺度的构造在苏格兰全长约250公里，显然是对巴罗夫序列中变质岩类型的空间分布的基本控制。然而，尽管经过了一个多世纪的研究，但它在全球范围内喀里多尼亚-阿巴拉契亚山脉建造过程中地壳的地球化学和构造演化中所起的作用仍然存在争议，而且解决得很差。人力资源将被开发，因为以现场和实验室为基础的博士研究生以及本科生的学士学位论文研究对该项目至关重要。皮阿格正在领导耶鲁大学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能够整合到地球科学展示中，每年有超过15万名参观者观看。这些游客中有很大一部分是小学生，他们中的许多人生活在纽黑文、布里奇波特和其他康涅狄格州城市的市中心。该展览将是康涅狄格州或罗德岛州唯一的此类展览，因此，对于博物馆的不同观众来说，它是一个重要的地区性科学和教育资源。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附带的CD/DVD，并制作一个互动网站；该项目将支持其中一本书的制作。

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.