Precambrian fluvial rocks of Arctic Canada, and their analogies to modern unvegetated rivers and extra-terrestrial fluvial landscapes

前寒武纪代表了近87%的已知地质时间，但有关5亿年前陆地景观和表面过程的可用信息取决于分散的岩石记录，通常暴露在偏远地区。河流沉积学是了解前寒武纪景观的物理和环境条件的重要工具，加拿大北极和北方欧洲的广大地区是研究前寒武纪河流岩石记录的理想场所。现有的模型对前植被河流假设，几乎所有的流浅，宽，弱弯曲，并占主导地位的闪光径流。这一假设与地球上现代无植被河流和火星上古代河流景观的各种地貌形成了对比。到目前为止，一些关于前寒武纪河流的基本问题仍然没有解决：前寒武纪河流与现代无植被河流相比，还是与外星河流景观相比？前寒武纪河流的演化是随着地球动力学、环境和生物强迫的变化而变化的吗？在泛大陆聚合和剧烈造山时期，没有植被的河流与现代河流有什么不同？ 要解决这些问题，需要对前寒武纪河流岩石记录进行全球评估，并对陆地和地外地区的无植被河流景观进行广泛的遥感，并证明水文循环。这项研究提案旨在介绍：关于加拿大北极和北方未开发沉积盆地的更高层次的地质知识;关于火星和土卫六上河流通道地貌的创新数据库;现代无植被河流的沉积模型;最后，前寒武纪、现代无植被和地外河流沉积动力学之间的关键比较。该研究提案涉及两个实地项目和两个遥感项目，并将涉及几名本科生和研究生的监督。与联邦、地区和国际地质调查局以及加拿大和欧洲的几所大学的合作正在进行或正在发展中。这项研究的成果将被证明是现代科学的几个新兴方面的基础，特别是行星地质学和河流资源管理。

The Precambrian represents almost 87% of known geological time, yet available information on terrestrial landscapes and surface processes before half a billion year ago depends on a scattered rock record, often exposed in remote locations. Fluvial sedimentology represents a prominent tool to understand the physical and environmental conditions of Precambrian landscapes, and vast regions of Arctic Canada and northern Europe represent the ideal playground to investigate the Precambrian fluvial rock record. Existing models on pre-vegetation rivers assume that virtually all streams were shallow, wide, weakly sinuous, and dominated by flashy runoff. This hypothesis contrasts with the varied geomorphology of modern unvegetated rivers on Earth and ancient fluvial landscapes on Mars. To date, a number of essential questions on Precambrian rivers remain unresolved: were Precambrian rivers comparable to modern unvegetated ones, or to extra-terrestrial fluvial landscapes? Did Precambrian rivers evolve through time in response to changing geodynamic, environmental, and biological forcing? And to what extent did unvegetated rivers differ from modern ones during periods of pan-continental assembly and intense mountain building? Answering these questions requires a worldwide assessment of the Precambrian fluvial rock record, and the extensive remote sensing of unvegetated fluvial landscapes on terrestrial and extra-terrestrial realms with demonstrated hydrologic cycles. This research proposal aims to introduce: a higher level of geological knowledge on under-explored sedimentary basins of Arctic Canada and northern Europe; an innovative database on the geomorphology of fluvial channels on Mars and Titan; a depositional model for modern unvegetated rivers; and finally, a critical comparison between the depositional dynamics of Precambrian, modern-unvegetated, and extra-terrestrial rivers. The research proposal is articulated on 2 field-based projects, and 2 remote-sensing-based projects, and will involve the supervision of several undergraduate and graduate students. Collaboration with federal, territorial, and international geological surveys and several Canadian and European universities is ongoing or in development. The outcomes of this research will prove fundamental for several emerging aspects of modern science, particularly planetary geology and river-resource management.