Thermal and compositional structure of the Superior Craton, Canada: Lithospheric architecture and implications for diamond prospectivity

加拿大上克拉通的热力和成分结构：岩石圈结构及其对钻石前景的影响

• 批准号: 549660-2019
• 负责人: Darbyshire, Fiona
• 金额: $ 1.52万
• 依托单位: Université du Québec à Montréal
• 依托单位国家: 加拿大
• 项目类别: Alliance Grants
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=700250
• 关键词: Thermal; compositional; structure; Superior; Craton

Mineral resources exploration through geophysics is usually associated with shallow subsurface imaging to find ore deposits. However, we can also learn a great deal by studying the deep, large-scale structure of the continents to find out more about how the minerals are created at depth and how they find their way to the surface. This "mineral systems" approach is gaining popularity in Canada, paving the way for a new generation of studies of deep structure. De Beers Canada has been actively exploring for diamonds in Canada since the 1960s and has operated 3 diamond mines in Ontario and the Northwest Territories. Diamonds are initially formed at great depth, under specific conditions of temperature and pressure, and are brought to the surface by volcanic eruptions that penetrate through the deep continental "root". The distribution of diamondiferous deposits is therefore controlled by both the deep structure of the continent and by the "pathways" created from depth to surface by later volcanic activity. In order to improve exploration targeting for the diamond industry, we need to apply new methods that image the deep structure of the continent in 3D, in particular, variations in the temperature and chemical composition of the rocks. We will combine a diverse range of data, using both geophysics and geochemistry, to model the structure of the crust and upper mantle beneath central-eastern Canada, where some of the world's oldest rocks are found, and where the ancient continental "root" is known to be thick enough to support diamond formation. De Beers Canada will subsequently use the model to evaluate potential exploration targets across the region, where they can apply field-based survey methods to study the target areas in more detail, using field-based exploration projects. The aim of this Alliance partnership project is therefore to aid the discovery of new economically-important diamond prospects in the eastern Canadian Shield.

通过地球物理学进行的矿产资源勘探通常与浅层地下成像相关，以寻找矿床。然而，我们还可以通过研究大陆深层的大规模结构来了解更多关于矿物质如何在深处形成以及它们如何到达地表的信息。这种“矿物系统”方法在加拿大越来越受欢迎，为新一代深层结构研究铺平了道路。 戴比尔斯加拿大公司自 1960 年代以来一直在加拿大积极勘探钻石，并在安大略省和西北地区经营着 3 个钻石矿。钻石最初是在特定的温度和压力条件下在很深的地方形成的，并通过穿透深层大陆“根”的火山喷发而被带到地表。因此，含金刚石矿床的分布既受到大陆深层结构的控制，也受到后来火山活动从深处到地表的“通道”的控制。 为了提高钻石行业的勘探目标，我们需要应用新的方法来成像 大陆的 3D 深层结构，特别是岩石的温度和化学成分的变化。我们将利用地球物理学和地球化学结合各种数据，对加拿大中东部地区的地壳和上地幔结构进行建模，那里发现了一些世界上最古老的岩石，也是古代大陆“根”所在的地方已知其厚度足以支撑钻石的形成。戴比尔斯加拿大公司随后将使用该模型来评估整个地区的潜在勘探目标，他们可以利用基于现场的勘探项目，应用基于现场的调查方法来更详细地研究目标区域。因此，该联盟合作伙伴项目的目的是帮助在加拿大地盾东部发现具有重要经济意义的新钻石矿区。