Impact Cratering: Processes, Products and Effects

撞击坑是太阳系中一种基本的、普遍存在的地质过程。它被认为是月球、水星、小行星以及火星和金星等地质活动较活跃的行星上最重要的表面过程。我们现在知道，陨石撞击事件在整个地球历史上也发挥了重要作用，塑造了地质景观，影响了生命的进化，并产生了具有重大经济意义的矿物和碳氢化合物矿床。这项研究计划将进一步加深我们对陨石撞击事件及其有益的科学和经济影响的理解。这对加拿大尤其重要，加拿大从萨德伯里影响结构内的采矿中获得了如此巨额的财富--萨德伯里影响结构是北美最富有的矿区。拟议研究的中心指导主题是“陨石撞击--过程、产品和影响”。这项研究计划的长期目标是检验陨石撞击坑可以(A)对现有生命产生负面影响；(B)产生适合于生命前化学的底物；(C)产生新的、独特的生命栖息地；以及(D)产生矿物和碳氢化合物矿床的假设。要解决这些假设，就需要了解撞击事件的基本过程和产物。因此，本文提出的研究将集中于促进我们对陨石撞击结构形成的四个关键隆起过程的理解：1)冲击熔融和变质作用；2)撞击抛射物就位；3)撞击坑坍塌；4)撞击产生的热液蚀变。本文主要对不同类型、不同保存状态的靶岩中的陨石坑进行了对比研究。这将使特定陨石坑的局部效应和特征与撞击陨石坑的更一般特征区分开来。现场工作构成了这项研究的基础，同时还使用了一系列尖端分析技术对样品进行调查，包括我的新的CFI/ORF资助的场发射电子微探头-加拿大第一个此类探头。

Impact cratering is a fundamental and ubiquitous geological process in the Solar System. It is considered the most important surface process on the Moon, Mercury, asteroids, and over large parts of the more geologically active planets of Mars and Venus. We now know that meteorite impact events have also played an important role throughout Earth's history, shaping the geological landscape, affecting the evolution of life, and producing mineral and hydrocarbon deposits of major economic significance. This research program will further our understanding of meteorite impact events and their beneficial scientific and economic effects. This is particularly important for Canada, which draws such a huge amount of wealth from the mining within the Sudbury impact structure - the richest mining district in North America. The central guiding theme of the proposed research is "Meteorite Impacts - Processes, Products, and Effects". The long-term objectives of this research program are to test the hypotheses that meteorite impact craters can (A) negatively affecting pre-existing life; (B) produce substrates suitable for prebiotic chemistry; (C) generate new, unique habitats for life; and (D) generate mineral and hydrocarbon deposits. Addressing these hypotheses requires an understanding of the fundamental processes and products of impact events. Thus, the research proposed here will focus on advancing our understanding of four key overarching processes important for the formation of meteorite impact structures: 1) shock melting and metamorphism; 2) impact ejecta emplacement; 3) impact crater collapse; and 4) impact-generated hydrothermal alteration. This work focuses on comparative study of impact craters within different types of target rocks and in different states of preservation. This will enable the differentiation of local effects and features of specific craters from more general features of impact craters. Fieldwork forms the foundation for this research coupled with the investigation of samples with a series of cutting-edge analytical techniques, including my new CFI/ORF-funded Field-Emission Electron Microprobe - the first of its kind in Canada.