Magmatic geochemistry of chalcophile and siderophile elements

亲铁和亲铁元素除了作为具有独特热、表面和电子性质的元素在社会上的用途外，长期以来一直被认为是导致类地行星小规模和大规模分化的过程的有价值的示踪物。*尽管它们在这方面很重要，但我们目前对这些元素的地球化学的大部分知识都是经验的，存在相当大的不确定性。然而，详细了解它们的地球化学行为对于全面解释自然丰度数据和开发先进的找矿模型是至关重要的。在过去的五年里，我的研究重点是开发技术和实施实验，以更好地评估岩浆作用在控制这些元素子集的行为方面的作用，即Re和铂族元素。在下一个资金周期，我计划扩大这项工作的范围，将鲜为人知的亲银非金属和类金属铅、硒、碲、砷和锑包括在内。这些元素通常存在于贱金属硫化物分离中，丰度从微量到次要。在某些情况下，可能是浓缩亲铁元素的矿物中的主要阴离子。因此，拟议的工作将专门关注这些元素在地壳和地幔中转移和浓缩的程度。这些实验将使用多伦多大学的设施、使用模拟地球深处极端条件的机器以及在高温下分离混合样品的新型离心机设备进行。这些实验的产品将使用最先进的分析技术进行表征，包括激光烧蚀电感耦合等离子体质谱仪和基于同步加速器的光谱分析。

The chalcophile and siderophile elements have long been recognised as valuable tracers of the processes responsible for small- and large-scale differentiation of the terrestrial planets, in addition to their societal uses as elements with unique thermal, surface and electronic properties.  Despite their importance in this regard, much of our current knowledge of the geochemistry of these elements is empirical, and subject to considerable uncertainty. However, a detailed understanding of their geochemical behaviour is essential to fully interpret natural abundance data, and develop advanced models for ore exploration.  Over the past five years, my research has focused on developing techniques and implementing experiments to better assess the role of magmatic processes in controlling the behaviour of a subset of these elements, namely Re and the platinum group elements.  In the next funding cycle, I plan to expand the scope of this work to include the poorly understood chalcophile non-metals and metalloids Pb, Se, Te, As and Sb.  These are elements that are typically present at trace to minor abundance levels in base metal sulfide segregations, and in some cases may be the principal anion in minerals that concentrate the siderophile elements.  The proposed work will specifically focus on the extent to which these elements are transferred and concentrated within Earth's crust and mantle.  Experiments will be done using facilities at University of Toronto, employing machines that simulate the extreme conditions of the deep Earth, and a novel centrifuge device for separating mixed samples at high temperature.  The products of these experiments will be characterised using state-of-the-art analytical techniques, including laser ablation ICP-MS, and synchrotron-based spectroscopy.