Lower Paleozoic stratigraphic architecture of the Cornwallis District and associated areas, Canadian high Arctic

加拿大高北极地区康沃利斯地区及相关地区的下古生界地层结构

• 批准号: RGPIN-2016-06596
• 负责人: Turner, Elizabeth
• 金额: $ 3.06万
• 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: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=616405
• 关键词: Lower; Paleozoic; stratigraphic; architecture; Cornwallis

The proposed research, to be undertaken by four graduate students and four undergraduates, will decipher the fundamental architecture of Canada’s lower Paleozoic (~540 to ~445 million years ago) sedimentary succession in the Arctic islands, a 3000 km-long and 2.5 km-thick paleo-continental margin that has never been studied in a detailed, regionally coherent paleoenvironmental-sedimentological-chronological context. Using standard field methods such as measuring and describing layered rock successions, and detailing the passage of time using the comparatively new method of stable isotope correlation together with fossil evidence of the passage of time, we will carefully tease apart the succession of Earth-surface environments preserved in this succession, in one particularly well exposed and representative nearshore to deep-marine transect, so that we can tell the story of what the northern 1/3 of Canada was like half a billion years ago. The work will consist of a thematically coherent, interlocking mosaic of studies that will produce, for the first time, a holistic chronology of northern Canada’s evolution through early development of its passive margin, evolution of a rimmed continental shelf and evaporite basin, and events associated with the mysterious M’Clintock orogeny, all of which play into the changing Earth-surface environments preserved in the rock succession. One of the most compelling aspects of the area to be studied is that it exposes a rare transect through the paleo-continental shelf-edge at a time when little is known about the nature of organisms living there; this study will, therefore, also shed light on important but poorly preserved paleoecosystems dating from early in the evolutionary history of animals. Furthermore, the composition and stratigraphic packaging of these strata, together with the structures that affected them, controlled later migration of metalliferous fluids associated with base-metal mineralisation in the Cornwallis zinc district (central high Arctic; includes past-producing Polaris mine), and extending all the way to the northern tip of Ellesmere Island. In spite of the Polaris mine’s successful 20-year mine-life, the detailed sedimentology and stratigraphy of the host rocks in the Franklinian basin, which have immense regional extent and consistency, and significant economic potential, have never been addressed in detail.

这项拟议的研究将由四名研究生和四名本科生进行，将破译加拿大下古生界(~5.4亿至~4.45亿年前)北极岛屿沉积序列的基本结构，北极岛屿是一个长3,000公里，厚2.5公里的古大陆边缘，从未在详细的、区域连贯的paleoenvironmental-sedimentological-chronological背景下进行研究。使用标准的野外方法，如测量和描述层状岩石序列，并使用相对较新的稳定同位素对比方法来详细描述时间的推移，以及时间推移的化石证据，我们将仔细梳理在这个序列中保存的地球表面环境的序列，在一个暴露得特别好和具有代表性的近岸到深海横断面上，这样我们就可以讲述5亿年前加拿大北部三分之一是什么样子的故事。这项工作将包括一个主题连贯、相互关联的研究马赛克拼接，这将首次产生加拿大北部通过其被动边缘的早期发展而产生的完整的年代学，边缘大陆架和蒸发岩盆地的演化，以及与神秘的M‘Clintock造山有关的事件，所有这些都将在岩石序列中保存的不断变化的地球表面环境中发挥作用。要研究的区域最引人注目的方面之一是，它暴露了一条罕见的横断面，穿过古大陆架边缘，当时人们对生活在那里的生物的性质知之甚少；因此，这项研究也将揭示从动物进化史早期开始的重要但保存不佳的古生态系统。此外，这些地层的组成和地层包装，以及影响它们的构造，控制了康沃利斯锌区(北极中部；包括过去生产的北极星矿)与贱金属矿化有关的金属流体后来的迁移，并一直延伸到埃尔斯米尔岛北端。尽管北极星矿成功地进行了长达20年的开采，但富兰克林盆地容矿岩石的详细沉积学和地层学从未被详细讨论过，这些沉积学和地层学具有巨大的区域范围和一致性，以及巨大的经济潜力。