Accessory minerals as windows into crustal processes

我提出的研究计划的主要目标是更好地了解化学元素是如何在地球内部融入所谓的辅助矿物的，比如锆石（ZrSiO4）。这些矿物在自然界中丰度相对较低，但它们通常含有大量的化学元素，如铀、钍和稀土元素（REE）。该研究项目建立在当前国际研究合作的基础上；新研究领域的一些最新进展；纽芬兰纪念大学地球科学专业教师的研究兴趣；还有那所机构里优秀的分析地球化学设备。为了完成部分拟议的研究项目，我将建立一个实验高温/高压地球化学设施来进行本提案中概述的实验；以及拉曼光谱和阴极发光成像实验室，以表征作为该研究计划一部分的合成材料。以前对化学元素如何融入辅助矿物的理解已经有了研究，但直到今天，控制这种分配的机制和过程（即电荷平衡、压力和温度的影响、流体或熔体成分、矿物结构和熔体结构等）仍然知之甚少。在接下来的五年里，我计划制定一个综合研究计划，将精心策划的高温/高压实验与精心挑选的自然样品分析相结合。这个研究项目的结果将提供一个更好的理解，这些辅助矿物如何广泛地用作分离这些矿物的岩石样本的地质历史的指标。

The main objectives of my proposed research program are to gain a better understanding of how chemical elements become incorporated in so-called accessory minerals, such as zircon (ZrSiO4), within the Earth.  These minerals occur in nature in relatively low abundances, however, they often contain significant quantities of chemical elements such as uranium, thorium, and the rare earth elements (REE).  This research program builds upon current international research collaborations; some recent developments in new research areas; research interests of faculty in Earth Sciences at Memorial University of Newfoundland; and the excellent analytical geochemistry facilities at that institution.  In order to complete some of the proposed research projects, I will establish an experimental high-temperature/high-pressure geochemistry facility to perform the experiments outlined in this proposal; and both a Raman spectroscopy and cathodoluminescence imaging laboratory, in order to characterize the materials synthesized as part of this research program.  Understanding how chemical elements incorporate in accessory minerals has been previously studied, but the mechanisms and processes (i.e., charge balancing, effects or pressure and temperature, fluid or melt composition, structure of the mineral and structure of the melt, etc.) that govern such partitioning remain poorly understood to this day.  Over the next five years, I plan to develop a combined research program that dovetails carefully planned high-temperature/high-pressure experiments with analyses of carefully selected natural samples.  The results from this research program will provide a much better understanding of how extensively these accessory minerals may be used as indicators of the geologic history of the rock samples from which these minerals were separated.