Accessory Minerals and Crustal Processes

9527014沃森，拟议研究的目的是增加我们对中、下地壳物理化学环境中的副矿物(特别是锆石)的了解。该项目将包括实验、天然材料分析和数值模拟相结合。计划开展的若干次级项目包括：(1)继续利用卢瑟福背散射光谱仪对关键同位素体系(U-Pb、Sm-ND、Lu-Hf)的母体和子体同位素进行晶格扩散测量；(2)校准与磷酸盐矿物共存的锆石的地质温度计；(3)晶体生长和溶解以及导致化学分区的过程的数值模拟；(4)内部结构成像(例如，带状、过度生长)以及这些特征与现场同位素分析的相关性；以及(5)发展阴极发光光谱(CL)与电子探针分析相结合的方法，以识别和区分单个锆石中不同生长区的来源。拟议的工作将提供充分利用辅助矿物作为地壳事件时间和温度记录器所需的工具和见解。

9527014 Watson The objective of the proposed research is to increase our understanding of accessory minerals (particularly zircon) in the physiochemical environment of the mid- to lower-crust. This project will include a combination of experiments, analyses of natural materials and numerical modeling. Several sub-projects are planned, including: (1) continuation of lattice diffusion measurements by Rutherford backscattering spectroscopy on the parent and daughter isotopes of key isotopic systems (U-Pb, Sm-Nd, Lu-Hf); (2) calibration of geothermometers involving zircon coexisting with a phosphate mineral; (3) numerical modeling of crystal growth and dissolution and the processes that lead to chemical zoning; (4) imaging of internal structures (e.g. zoning, overgrowths) and correlation of these features with in situ isotopic analyses; and (5) development of cathodluminescence spectroscopy (CL) in combination with electron microprobe analysis as a means of identifying and distinguishing the origin of various growth regions within individual zircons. The proposed work will provide the tools and insights needed to take full advantage of accessory minerals as recorders of the timing and temperature of crustal events.