Arctic Basin Analysis and Earth Systems Change

北极盆地分析与地球系统变化

• 批准号: RGPIN-2014-06639
• 负责人: Beauchamp, Benoit
• 金额: $ 2.19万
• 依托单位: University of Calgary
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2014
• 资助国家: 加拿大
• 起止时间: 2014-01-01 至 2015-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=567944
• 关键词: Arctic; Basin; Analysis; Earth; Systems

Our work in past years has shown that the Earth history was marked by a series of irreversible setbacks in the environments and in the biosphere during the 70 million year interval (a time known as the Permian) that preceded the largest mass extinction ever recorded. The extinction happened just before the Permian-Triassic (P-T) boundary some 252 million years ago. The latest Permian extinction (LPE) was far more devastating than the end-Cretaceous extinction that wiped out the dinosaurs, which occurred some 187 million years later. There were no dinosaurs prior to the latest Permian extinction, but there was a rich environment populated by highly evolved plants and animals on land and in the sea, very much like today’s environments. The final blow to life came as the result of a massive volcanic eruption in Siberia, which also ignited coal deposits, fouling the air and the ocean, and sending the world’s ecosystems into a tailspin. The Siberian volcanic eruption was the last in a series of unfortunate events that tipped the world into an alternate state. It took our planet five million years to recover from the devastation. The LPE is increasingly viewed as the worst case scenario that could result from the unattended anthropogenic burning of fossil fuel. Scientists and popular writers see the extinction as an ominous example of what could happen to our planet should we continue to pump CO2 in the atmosphere—runaway greenhouse, rapid temperature rise, ocean acidification, migration of climate belts, mass extinction. The LPE was a major “state shift” in the Earth’s biosphere, and many fear that humanity may be facing a similar shift if we continue to force biological systems towards their tipping point. Of course man was not around 252 million years ago and cannot be blamed for the extinction; so we have to look for other explanations. This research is about finding out what the causes of such a devastating environmental upheaval might have been. In our search for answers, we will be studying the Sverdrup Basin of Arctic Canada (NWT and Nunavut), which contains a thick sedimentary succession rich in geological information about the events that preceded and postdated the latest Permian extinction. We are determined to demonstrate that the Sverdrup Basin has recorded stratigraphic and environmental changes that can only be explained by tectonic processes originating in the rigid crust of the earth or in the more viscous mantle beneath the crust. Teams of graduate students will collect vast amount of data in the Arctic, mostly in the mountainous regions of Ellesmere and Axel Heiberg islands in Nunavut. Our scientific approach is called "basin analysis" and it integrates classic disciplines such as stratigraphy and sedimentology with other disciplines such as geochemistry, geophysics and paleoclimatology, to name a few. One positive outcome of this research will be to generate a productive dialogue between stratigraphers and geophysicists, who both have strong interests in the origin of sedimentary basins and their sediment fills, but who have not engaged one another in any meaningful way in the past. Another outcome of this research will be to shed light on the modern debate about the fate of our planet as viewed through the rich historical record of an old sedimentary succession. Also the Sverdrup Basin is Canada’s most promising frontier basin, with known oil and gas fields discovered nearly 40 years ago. Our research will contribute to understanding the origin of the rocks that contain these hydrocarbons. Finally, this project will train a new generation of scientists in the art of conducting research in a challenging Arctic setting, at a time when an older cohort of Arctic scientists in governments and universities is retiring.

我们在过去几年的工作表明，地球历史的特点是在有史以来最大的大规模灭绝之前的7000万年间隔（即二叠纪）期间，环境和生物圈发生了一系列不可逆转的挫折。灭绝发生在大约2.52亿年前的二叠纪-三叠纪（P-T）边界之前。最新的二叠纪灭绝（LPE）比白垩纪末灭绝恐龙的破坏性要大得多，后者发生在大约1.87亿年后。在最近的二叠纪灭绝之前没有恐龙，但在陆地和海洋中有一个由高度进化的植物和动物居住的丰富环境，非常像今天的环境。对生命的最后一击来自西伯利亚的一次大规模火山爆发，火山爆发也点燃了煤炭矿床，污染了空气和海洋，并使世界生态系统陷入混乱。西伯利亚火山爆发是一系列不幸事件中的最后一次，这些事件使世界陷入了另一种状态。我们的星球花了500万年才从毁灭中恢复过来。LPE越来越被视为无人看管的人类化石燃料燃烧可能导致的最坏情况。科学家和流行作家认为，如果我们继续向大气中排放二氧化碳，地球可能会发生什么，灭绝是一个不祥的例子失控的温室效应，温度迅速上升，海洋酸化，气候带迁移，大规模灭绝。LPE是地球生物圈的一次重大“状态转变”，许多人担心，如果我们继续迫使生物系统走向临界点，人类可能会面临类似的转变。当然，人类在2.52亿年前并不存在，不能将灭绝归咎于人类;所以我们必须寻找其他解释。这项研究是为了找出造成这种破坏性环境剧变的原因。在我们寻找答案的过程中，我们将研究加拿大北极地区的斯维尔德鲁普盆地（西北地区和努纳武特），该盆地包含丰富的沉积序列，其中包含有关最近一次二叠纪灭绝之前和之后事件的地质信息。我们决心证明，斯维尔德鲁普盆地记录的地层和环境变化，只能用起源于坚硬的地壳或地壳下更粘稠的地幔的构造过程来解释。研究生团队将在北极地区收集大量数据，主要是在努纳武特的埃尔斯米尔和阿克塞尔海伯格群岛的山区。我们的科学方法被称为“盆地分析”，它将地层学和沉积学等经典学科与地球化学、地球物理学和古气候学等其他学科相结合。这项研究的一个积极成果将是在地层学家和沉积学家之间产生富有成效的对话，他们都对沉积盆地的起源及其沉积物填充物有浓厚的兴趣，但过去没有以任何有意义的方式相互接触。这项研究的另一个成果将是通过古老沉积序列的丰富历史记录来阐明关于我们星球命运的现代辩论。此外，斯维尔德鲁普盆地是加拿大最有前途的前沿盆地，近40年前就发现了已知的油气田。我们的研究将有助于了解含有这些碳氢化合物的岩石的起源。最后，该项目将培训新一代科学家在具有挑战性的北极环境中开展研究的艺术，而此时政府和大学的老一代北极科学家正在退休。