Imaging and characterization of rifted continental margin structures using geophysical methods: seeking deeper constraints and their tectonic implications

使用地球物理方法对裂谷大陆边缘结构进行成像和表征：寻求更深层次的约束及其构造意义

• 批准号: RGPIN-2017-04258
• 负责人: Welford, JKim
• 金额: $ 1.68万
• 依托单位: Memorial University of Newfoundland
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=751192
• 关键词: Imaging; characterization; rifted; continental; margin

Canada's submarine limits on the East Coast and in the Arctic are characterized by rifted continental margins, the products of the opening of modern oceans. Despite their territorial and economic importance due to hosting significant energy reserves, these margins remain largely underexplored and the processes that created them are not fully understood. Rifted continental margins are generally classified as magma-rich/volcanic margins or magma-poor/non-volcanic margins. Canada's East Coast hosts both types of margins as well as the transitions between them, providing a natural laboratory for studying rifting processes and how they vary along a rifted continental margin. Great insight can also be obtained by stitching the oceans back together to study how well the conjugate margins match, how asymmetries develop, and whether those asymmetries existed long before the oceans opened. These rifting processes have a profound impact on subsequent sediment deposition and basin evolution, such that developing a better understanding of the crustal variability beneath them can reduce exploration risk and cost. My research program involves studying rifted continental margins and their conjugates in order to contribute to global knowledge on how these margins develop while providing insights on how these rifting processes impact petroleum systems. The short-term goals are to better constrain our current crustal models of rifted continental and transitional crust by taking advantage of new geophysical datasets being acquired on the eastern Canadian margin, as well as on the conjugate margins. These efforts will involve (1) seismic processing work to provide improved images of the crustal variations both along and across conjugate pairs; (2) detailed seismic interpretation work to relate geological boundaries with their geophysical character both within and across conjugate pairs; and (3) gravity inversion work to extend newfound seismic constraints to greater depth and over a broader region. The longer-term goals are to continue to undertake original scientific crustal-scale seismic experiments, in conjunction with industry, government, and international collaborators, over key regions where data gaps remain and where the current state of knowledge does not adequately explain the observations.The proposed research is important to the energy exploration industry and all levels of government due to the territorial and economic impact of enhanced exploration. The gravity inversion methods developed will be of particular strategic importance to Canada as they will provide a low-cost approach to characterizing the deep structure of the Arctic where the federal government has identified responsible development as a research priority. Lastly, 10 highly qualified geoscientists will be trained for work in academia, government, and industry in Canada and internationally.

加拿大东海岸和北极的潜艇界限的特点是大陆边缘裂开，这是现代海洋开放的产物。尽管由于拥有大量能源储备而具有领土和经济重要性，但这些利润空间在很大程度上仍未得到充分开发，并且创造它们的过程也尚未完全了解。裂谷大陆边缘通常分为富岩浆/火山边缘或贫岩浆/非火山边缘。加拿大东海岸拥有两种类型的边缘以及它们之间的过渡，为研究裂谷过程及其沿裂谷大陆边缘的变化提供了一个天然实验室。通过将海洋重新缝合在一起，研究共轭边缘的匹配程度、不对称性如何发展以及这些不对称性是否早在海洋开放之前就存在，也可以获得深刻的见解。这些裂谷过程对随后的沉积物沉积和盆地演化产生深远影响，因此更好地了解其下方的地壳变化可以降低勘探风险和成本。我的研究项目包括研究裂谷大陆边缘及其结合物，以便为全球了解这些边缘如何发展做出贡献，同时提供有关这些裂谷过程如何影响石油系统的见解。短期目标是通过利用在加拿大东部边缘以及共轭边缘获取的新地球物理数据集，更好地约束我们当前的裂谷大陆和过渡地壳的地壳模型。这些工作将涉及（1）地震处理工作，以提供沿共轭对和跨共轭对的地壳变化的改进图像； (2) 详细的地震解释工作，将共轭对内部和共轭对之间的地质边界与其地球物理特征联系起来； (3)重力反演工作将新发现的地震约束扩展到更大的深度和更广泛的区域。长期目标是继续与工业界、政府和国际合作者合作，在数据仍然存在差距以及当前知识状况无法充分解释观测结果的关键区域进行原创的科学地壳规模地震实验。由于加强勘探对领土和经济的影响，拟议的研究对能源勘探行业和各级政府都很重要。开发的重力反演方法对加拿大具有特别的战略意义，因为它们将提供一种低成本的方法来表征北极的深层结构，联邦政府已将负责任的开发确定为研究重点。最后，10 名高素质的地球科学家将接受培训，以便在加拿大和国际学术界、政府和工业界工作。