Fingerprinting glacial processes for diamond exploration on Baffin Island

加拿大是世界上第三大钻石生产国（自1998年以来每年约24亿美元）。钻石产量从零增加到1500万克拉，仅来自四个矿场（三个在西北地区，一个在安大略省北部）。每年在钻石勘探上的花费可能超过1亿美元，部分原因是北部偏远，部分原因是使用昂贵的地球物理方法来定位钻石矿石（金伯利岩）的露头，这些露头可能小到半径几米。在过去的两百万年里，金伯利岩经常被沉积物覆盖，或者被冰原侵蚀，散落在数百平方公里的地方。因此，大部分的勘探都依赖于我们解释冰川动力学历史的能力，以及追踪金伯利岩“面包屑”的来源。诸如冰流方向的变化、多次冰川作用和控制金伯利岩侵蚀量或运输的冰下条件等复杂性使这种矿物勘探方法具有风险。拟议研究的目标是开发新的和创新的方法，以提高我们对冰川过程的认识，以及它们如何影响加拿大北部，特别是巴芬岛的矿产勘探。我们将结合一种新的表征冰下条件的同位素地球化学方法，以及建立在数十年冰川沉积物矿物勘探基础上的精炼现场策略。努纳武特巴芬岛的霍尔半岛是测试这种方法的理想地点，因为它有金伯利岩的明显迹象，而且众所周知，它表现出的冰川复杂性据信在加拿大其他地方也存在。我们的NSERC-CRD行业合作伙伴Peregrine Diamonds公司正在通过实物和匹配支持来促进这些矿产勘探开发的测试，以抵消在这个偏远地区进行测绘、采样和同位素地球化学的高昂成本。

Canada is the third largest diamond producer by value worldwide (approximately $2.4 billion per year since 1998). Diamond production has increased from zero to 15 million carats from only four mines (three in the Northwest Territories and one in northern Ontario). Over a hundred million dollars can be spent in a single year on diamond exploration, in part due to the remoteness of the north, and in part due to use of expensive geophysical methods to locate outcroppings of diamond ore (kimberlite) that may be as small as a few metres radius. Often the kimberlite is covered by sediment or is eroded and scattered over hundreds of square kilometres by ice sheets over the past two million years. Therefore much of the exploration relies on our ability to interpret the history of glacial dynamics and trace the kimberlite 'bread crumbs' back to their source. Complexities such as changes in ice flow direction, multiple glaciations, and subglacial conditions that control the amount of erosion or transportation of kimberlite make this mineral exploration approach risky. The goal of the proposed research is to develop new and innovative approaches that will improve our knowledge of glacial processes and how they affect mineral exploration in northern Canada, particularly on Baffin Island. We will couple a novel isotope geochemistry method that characterises the subglacial conditions, with a refined field strategy that builds on decades of mineral exploration in glacial sediment. Hall Peninsula, Baffin Island, Nunavut, is an ideal location for the test of this approach because it has significant indications of kimberlite and is known to exhibit the glacial complexities believed to operate elsewhere in Canada. Our NSERC-CRD industry partner Peregrine Diamonds Inc is facilitating the testing of these developments in mineral exploration with in-kind and matching support at the level required to offset high costs of mapping, sampling, and isotope geochemistry for this remote setting.