An intensive study of impact craters to "probe" and "gauge" the complex geologic history of Mars and to further understand cratering as a formative process on terrestrial bodies

对撞击坑进行深入研究，以“探测”和“测量”火星复杂的地质历史，并进一步了解撞击坑作为地球物体的形成过程

• 批准号: RGPIN-2020-06418
• 负责人: Tornabene, Livio
• 金额: $ 2.19万
• 依托单位: University of Western Ontario
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=741198
• 关键词: intensive; study; impact; craters; probe

Impact cratering is the most ubiquitous geologic process acting on solid planetary surfaces throughout the solar system; thereby, it played a significant role in the early formation, modification and in some cases the aqueous alteration of planetary crusts. Mounting observational evidence supports that impact cratering has not only physically modified the rocky surfaces of Earth and Mars but may have also played a significant role in the evolution of early life and facilitated the concentration of resources. The study of impact craters may be used to elucidate the complex geologic history of the planetary bodies that host them. Craters are generally consistent morphologically, making them one of the most easily recognized features on planetary surfaces. As such, they are also useful as natural "gauges" sensitive to and recording the effects of the geologic processes that modify them over time. Impact craters are classified by their general morphology and morphometry into simple, transitional, complex, which has been determined to be controlled by the size of the crater, gravity of the body and the strength of the target materials in which it formed. Furthermore, craters effectively excavate, uplift and expose subsurface rocks that may not otherwise be exposed at the surface by other processes (particularly on Mars where plate tectonics is lacking). Thereby, craters that are well-exposed act as natural "probes" of the composition, stratigraphy and structure of shallow to deep interiors of planetary bodies. The proposed research program focuses on the identification and intensive study of the best-preserved and -exposed craters on Mars and an analysis, synthesis and interpretation of orbital visible, spectral, thermophysical and elevation data sets covering them. The best-preserved impact craters provide the clearest observations and insights into various aspects of the cratering process; furthermore, they will continue to provide a baseline for studies of erosion and deposition (i.e., degradation) on Mars. A study of the best-exposed complex craters, focusing on ejecta, crater wall/terraces, central structures, etc., will provide information on the composition, rheology/strength and structure of various levels of the shallow to deep subsurface. The proposed research will continue to expand on our knowledge on the impact processes, and their usefulness as a natural "tool" for elucidating other processes that have and continue to act on planetary bodies. Although the emphasis of this research program is not specifically terrestrial-based, the data and methods employed here are similar to those utilized by exploration geology, geophysics, and environmental remote sensing, and even includes image analysis techniques used for national defense. As such, HQP involved in this research program will learn fundamental skills that are directly applicable to other fields.

撞击坑是作用于整个太阳系固体行星表面的最普遍的地质过程；因此，它在行星结壳的早期形成、改造以及在某些情况下的水蚀变中发挥了重要作用。越来越多的观测证据支持，撞击陨石坑不仅在物理上改变了地球和火星的岩石表面，而且可能在早期生命的进化中发挥了重要作用，并促进了资源的集中。对陨石坑的研究可以用来阐明它们所在的行星体复杂的地质历史。陨石坑在形态上通常是一致的，使它们成为行星表面最容易识别的特征之一。因此，它们也是有用的天然“量规”，敏感于并记录随着时间的推移修改它们的地质过程的影响。根据撞击坑的一般形态和形态计量学，撞击坑可分为简单、过渡和复杂三种类型，它们被确定为由陨石坑的大小、物体的重力和形成它的目标材料的强度所控制。此外，陨石坑有效地挖掘、抬升和暴露了地下岩石，否则这些岩石可能不会被其他过程暴露在地表(特别是在缺乏板块构造的火星上)。因此，暴露得很好的陨石坑就像是对行星体从浅到深内部的组成、地层和结构的天然“探测器”。拟议的研究计划侧重于识别和深入研究火星上保存最完好和暴露的陨石坑，并分析、合成和解释涵盖这些陨石坑的轨道可见光、光谱、热物理和海拔数据集。保存最完好的撞击坑提供了对陨石坑过程各个方面最清晰的观察和洞察；此外，它们将继续为研究火星上的侵蚀和沉积(即退化)提供基线。对暴露最好的复杂陨石坑的研究，重点是喷出物、陨石坑墙/台地、中央结构等，将提供关于浅层至深层地下各级的成分、流变性/强度和结构的信息。拟议的研究将继续扩大我们关于撞击过程的知识，以及它们作为阐明已经并将继续作用于行星体的其他过程的自然“工具”的有用性。虽然这项研究的重点不是专门针对陆地的，但这里使用的数据和方法类似于勘探地质、地球物理和环境遥感所使用的数据和方法，甚至包括用于国防的图像分析技术。因此，参与该研究计划的HQP将学习直接适用于其他领域的基本技能。