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

加拿大北极地区的前寒武纪河流岩石及其与现代无植被河流和地外河流景观的类比

• 批准号: RGPIN-2016-05720
• 负责人: Ielpi, Alessandro
• 金额: $ 1.99万
• 依托单位: Laurentian University of Sudbury
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=654213
• 关键词: Precambrian; fluvial; rocks; Arctic; Canada

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.**

前寒武纪几乎占已知地质时期的 87%，但 5 亿年前的陆地景观和地表过程的可用信息取决于分散的岩石记录，这些记录通常暴露在偏远地区。河流沉积学是了解前寒武纪地貌物理和环境条件的重要工具，加拿大北极地区和北欧的广大地区是研究前寒武纪河流岩石记录的理想场所。现有的关于植被前河流的模型假设几乎所有的溪流都是浅、宽、微弱蜿蜒的，并且以快速径流为主。这一假说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鲜明对比。迄今为止，关于前寒武纪河流的许多基本问题仍未解决：前寒武纪河流是否可与现代未植被的河流或地外河流景观相媲美？前寒武纪河流是否随着时间的推移而演化，以应对不断变化的地球动力学、环境和生物强迫？在泛大陆聚合和剧烈造山时期，未植被的河流与现代河流有何不同？********回答这些问题需要对前寒武纪河流岩石记录进行全球评估，并进行广泛的遥感监测。陆地和地外领域未植被的河流景观，具有已证实的水文循环。该研究计划旨在介绍： 关于加拿大北极地区和北欧尚未勘探的沉积盆地的更高水平的地质知识；关于火星和土卫六河流河道地貌的创新数据库；现代无植被河流的沉积模型；最后，对前寒武纪河流、现代无植被河流和地外河流的沉积动力学进行了批判性比较。该研究计划涉及 2 个实地项目和 2 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机构以及加拿大和欧洲几所大学的合作正在进行或正在发展中。这项研究的成果将对现代科学的几个新兴方面，特别是行星地质学和河流资源管理具有基础性意义。**