Meteorite impact craters as natural "probes" and "gauges" on planetary surfaces

陨石撞击坑是行星表面的天然“探针”和“测量仪”

• 批准号: RGPIN-2014-04215
• 负责人: Tornabene, Livio
• 金额: $ 2.11万
• 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: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=587673
• 关键词: Meteorite; impact; craters; natural; probes

Impact cratering is the most ubiquitous geologic process acting on solid planetary surfaces throughout the solar system and, thereby, played a significant role in the early formation, modification and in some cases the aqueous alteration of planetary crusts. Mounting 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 the concentration of mineral resources via the hydrothermal activity (i.e., heat-driven circulation of fluids). Impact craters are relatively consistent in morphology making them one of the most easily recognized features on planetary surfaces. Thereby, they are also useful as “probes” and “gauges” of the target properties, and geologic processes that modify planetary surfaces, respectively. Craters excavate, uplift and expose subsurface rocks that may not otherwise be exposed by other processes, and in some cases provide the only bedrock samples of the deep subsurface. Spectral remote sensing of theses features is often employed to identify these subsurface rocks on planetary bodies. However, there are various crater-related effects within these features that need to be better understood, in order to fully understand their effects on the rocks. Pristine crater morphology and morphometry (e.g., crater depth) can be used as a standard to understand target material properties and the effects and rates of subsequent modifying geologic processes. In addition, pristine craters offer us a glimpse of the relatively unmodified primary crater deposits, providing insights into the impact cratering process itself, and potentially paleo-environments on planetary bodies with atmospheres and target volatiles (e.g., water). The long-term goals of my research program are to, 1) improve our understanding of the impact cratering process as a geologic process, and 2) learn about the geological history of upper crust and surface of Mars through remote sensing studies of its most ubiquitous landform – impact craters. This program aims to achieve these goals via three testable hypotheses, each of which are divided into four objectives involving the analysis and interpretation of orbital spectral, visible, thermophysical and elevation data sets of the Martian surface. Although the emphasis is not specifically terrestrial-based, the processing, visualization, analysis and interpretation of these data sets are similar to those utilized by exploration geology, geophysics, environmental remote sensing, and even employed for the purposes of national defense. As such, Highly Qualified Personnel (HQP) involved in this research program will learn techniques that are directly applicable to these fields.

撞击陨石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。越来越多的证据表明，撞击陨石坑不仅在物理上改变了地球和火星的岩石表面，而且可能还通过热液活动(即热驱动的流体循环)在早期生命的演化和矿物资源的集中中发挥了重要作用。撞击坑在形态上相对一致，使它们成为行星表面最容易识别的特征之一。因此，它们还分别用作目标属性的“探测器”和“量规”，以及修改行星表面的地质过程。陨石坑挖掘、抬升和暴露地下岩石，否则这些岩石可能不会被其他过程暴露，在某些情况下，它们提供了深地下唯一的基岩样本。对这些特征的光谱遥感通常被用来识别行星体内的这些地下岩石。然而，在这些特征中有各种与陨石坑相关的效应，需要更好地了解，以便充分了解它们对岩石的影响。原始的陨石坑形态和形态测量(例如，陨石坑深度)可以作为标准，以了解目标材料的属性以及随后的地质修改过程的影响和速率。此外，原始陨石坑为我们提供了相对未经修改的原始陨石坑沉积物的一瞥，提供了对撞击陨石坑过程本身的洞察，以及对具有大气和目标挥发物(例如水)的行星体内潜在的古环境的洞察。 我的研究计划的长期目标是，1)提高我们对撞击陨石坑过程作为地质过程的理解，2)通过对火星最普遍的地貌-撞击陨石坑的遥感研究，了解火星上地壳和地表的地质历史。该计划旨在通过三个可测试的假设来实现这些目标，每个假设分为四个目标，涉及分析和解释火星表面的轨道光谱、可见光、热物理和海拔数据集。 虽然重点不是专门基于陆地的，但这些数据集的处理、可视化、分析和解释类似于勘探地质、地球物理、环境遥感，甚至用于国防目的。因此，参与该研究计划的高素质人员(HQP)将学习直接适用于这些领域的技术。