Fingerprinting glacial processes for diamond exploration on Baffin Island

按价值计算，加拿大是世界第三大钻石生产国(自1998年以来每年约为24亿美元)。仅有四个矿场(三个在西北地区，一个在安大略省北部)的钻石产量从零增加到1500万克拉。一年可花费1亿多美元用于钻石勘探，部分原因是北部地处偏远，部分原因是使用昂贵的地球物理方法来定位可能小至几米半径的钻石矿石(金伯利岩)的露头。在过去的两百万年里，金伯利岩常常被沉积物覆盖，或者被冰盖侵蚀并散落在数百平方公里的土地上。因此，我们的探索在很大程度上依赖于我们解释冰川动力学历史和追踪金伯利岩“面包屑”的能力。复杂的情况，如冰流方向的变化，多个冰川，以及控制金伯利岩侵蚀或运输的冰下条件，使这种矿产勘探方法具有风险。拟议研究的目标是开发新的创新方法，提高我们对冰川过程及其如何影响加拿大北部，特别是巴芬岛矿物勘探的了解。我们将结合一种表征冰下条件的新的同位素地球化学方法，以及建立在数十年冰川沉积物矿产勘探基础上的精细化野外战略。努纳武特巴芬岛的霍尔半岛是测试这一方法的理想地点，因为它有明显的金伯利岩迹象，而且众所周知，它展示了据信在加拿大其他地方运行的冰川复杂性。我们的NSERC-CRD行业合作伙伴百富勤钻石公司正在利用实物和匹配支持促进矿产勘探中的这些开发项目的测试，以抵消这一偏远地区的测绘、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.