Nitrogen-Isotopic Studies of High-Temperature Fluid-Rock Interactions

9405625关于拟议的研究将扩展现有的研究，以测试氮同位素系统作为高温流体-岩石相互作用的示踪剂在变质和岩浆系统中的用途。该项目将(1)限制氮同位素系统中的分馏来源(通过熔融、脱挥发等；主要是在氮气、氨和NH4+之间)，(2)确定各种岩浆、变质和大气流体来源的氮同位素特征，以及(3)改进从硅酸盐材料中更常规地提取氮以进行同位素分析的技术。头两个目标将通过对三个野外区域的氮同位素系统学研究来实现：英格兰的斯基多花岗岩和极光，加利福尼亚州的桦树溪花岗岩和极光，以及加利福尼亚州的半岛山脉岩基。第三个目标将涉及继续高温燃烧和聚变技术的实验，进一步降低分析空白，以及改进极小氮气样品的质谱学技术。

9405625 Bebout The proposed research will extend existing research to test the utility of the N-isotopic system as a tracer of high temperature fluid-rock interactions, both in metamorphic and magmatic systems. The project will (1) constrain sources of fractionation in the N isotopic system (through melting, devolatilization, etc.; primarily among N2, NH3, and NH4+), (2) identify N-isotopic signatures characteristic of various magmatic, metamorphic, and meteoric fluid sources, and (3) improve techniques for the more routine extraction of N from silicate materials for isotopic analysis. The first two goals will be achieved through study of N isotopic systematics for three field areas: the Skiddaw Granite and Aureole, England, the Birch Creek Granite and Aureole, California; and the Peninsula Ranges Batholith, California. The third goal will involve continuation of experimentation with high-temperature combustion and fusion techniques, further lowering of analytical blanks, and improvement of techniques for mass spectrometry of extremely small N2 samples.