The geology, mineralogy, and geochemistry of gem and strategic element occurrences and the crystal chemistry of borosilicate minerals

摘要在加拿大广阔但未充分勘探和未开发的大片土地上反复发现有色宝石和战略元素，表明有可能成为重要的经济矿藏的重要生产者。这项研究计划将通过增加我们对形成这些矿床所涉及的地质过程的科学理解，来帮助勘探这些矿床。该研究计划的目标包括四个项目领域：宝石矿床、伟晶岩、碳酸盐岩和碱性侵入岩以及硼硅酸盐。宝石矿床很罕见，因为生产它们所需的地质条件非常特殊；例如，为了形成祖母绿，必须与铬或钒接触，这两种元素在非常不同的地球化学环境中出现。然而，除了钻石之外，在制定宝石材料勘探协议方面做的工作很少。我的目标是确定这些事件是如何形成的，以便开发这样的协议。为了实现这一目标，我将：(1)研究努纳武特新发现的Anuri祖母绿远景；(2)将哥伦比亚为祖母绿制定的勘探标准应用于加拿大；(3)表征和开发蓝宝石的矿床模型；(4)在巴芬岛上开发宝石尖晶石。在加拿大的科迪勒时代，伟晶岩在很大程度上被忽视了，尽管一个多世纪以来，美国的科迪勒伟晶岩一直是战略元素的重要生产者，这些元素是那些供应中断风险最大的元素，或者对一个国家的经济或国防至关重要，以及宝石。我的长期目标是填补关于加拿大科迪莱拉伟晶岩的特征、分类和形成的信息空白。为了推进这一目标，我将进行地质填图，并研究(1)育空地区新发现的劳氏伟晶岩田和(2)山体的地球化学和年代学。公元前的Begbie伟晶岩。有关硼硅酸盐矿物的信息有助于揭示地质系统的演化，因为在大多数熔体中，硼既是一种不相容的元素，也是一种挥发物。因此，我的目标是全面描述选定的硼硅酸盐矿物的晶体化学，以便确定哪些地质环境一定引起了这些特征。此外，云母石(第二种最常见的硼硅酸盐矿物)用于制造高级陶瓷，超族成员在结构上与一大类具有潜在商业应用的合成微孔化合物有关。我将继续推进这一目标的工作，(1)确定水分子的位置和取向，(2)开始研究Sakhaite-Harkerite系列硼硅酸盐矿物的晶体化学，(3)研究非电气石硼硅酸盐的稳定和放射性同位素组成。世界各地的碳酸盐岩矿床历来是战略元素资源的来源；因此，我将继续研究加拿大西部的碳酸盐岩和碱性侵入岩。我的目标是充分描述这些战略元素的赋存状态，以便就成矿作用的成因得出结论，并开发有助于勘探的矿床模型。为了推进这一目标，我将研究(1)公元前金碳酸盐岩和(2)育空地区的班迪托和汀侵入体。

SUMMARY Repeated discoveries of both colored gems and strategic elements in Canada's extensive, but insufficiently explored and consequently untapped, land mass indicate the potential of becoming a significant producer of economically important mineral deposits. This research program will aid in exploration for such deposits by increasing our scientific understanding of the geological processes involved in forming them. The objectives of this research program form four project areas: gem deposits, pegmatites, carbonatite and alkaline intrusions, and borosilicates. Gem deposits are rare because the geological conditions needed to produce them are exceptional; for example, in order for emerald to form Be must come into contact with Cr or V, which occur in very different geochemical environments. However, with the exception of diamond, little has been done to develop exploration protocols for gem materials. My objective is to determine how these occurrences form, so that such protocols can be developed. In order to accomplish this objective, I will: (1) study the newly discovered Anuri emerald prospect in Nunavut, (2) apply exploration criteria developed for emeralds in Colombia to Canada, (3) characterize and develop deposit models for sapphire and (4) gem spinel on Baffin Island. Pegmatites have largely been overlooked in the Canadian Cordillera, even though Cordilleran pegmatites in the US have been significant producers of strategic elements, which are those elements that are at greatest risk of supply disruptions or are important to a country’s economy or defense, and gemstones for over a century. My long-term objective is to fill the information gap regarding the characteristics, classification, and formation of pegmatites of the Canadian Cordillera. In order to advance this objective, I will conduct geological mapping and study the geochemistry and geochronology of (1) the newly discovered Rau pegmatite field in the Yukon and (2) the Mt. Begbie pegmatites in BC. Information on the borosilicate minerals sheds light on the evolution of geological systems due to boron's role as both an incompatible element and a volatile in most melts. My objective is therefore to fully describe the crystal chemistry of selected borosilicate minerals so that it may be determined what geological circumstances must have given rise to those characteristics. In addition, dumortierite (the second most common borosilicate mineral) is used to make high-grade ceramics, and members of the supergroup are structurally related to a large group of synthetic microporous compounds that have potential commercial applications. I will continue advancing my work on this objective by (1) determining the positions and orientations of water molecules, (2) begin to study the crystal chemistry of the sakhaite-harkerite series of borosilicate minerals, and (3) investigate the stable and radiogenic isotopic compositions of the non-tourmaline borosilicates. Carbonatite deposits around the world have historically been sources of strategic element resources; therefore, I will continue my work on carbonatite and alkaline intrusions in western Canada. My objective is to fully characterize these strategic element occurrences in order to draw conclusions about the genesis of the mineralization, and to develop deposit models to aid in exploration. In order to advance this objective, I will study (1) the Kin carbonatite in BC and (2) the Bandito and Ting intrusions in the Yukon.