Lithospheric structure and tectonics based on seismic reflection, refraction and other geophysical studies

基于地震反射、折射和其他地球物理研究的岩石圈结构和构造

• 批准号: 7707-2009
• 负责人: Clowes, Ronald
• 金额: $ 1.06万
• 依托单位: University of British Columbia
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2012
• 资助国家: 加拿大
• 起止时间: 2012-01-01 至 2013-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=496861
• 关键词: Lithospheric; structure; tectonics; based; seismic

The lithosphere (the rigid outer shell of Earth) of North America developed over the past 4 billion years to generate the collage of geological features that we now see. Determination of present lithospheric structure, and how it formed over geological time, represent basic knowledge about "inner space" that is just as important as knowledge of "outer space". Such knowledge also has practical applications: regional information useful for diamond, base metal and petroleum companies; and why and how earthquakes occur. The three proposed projects in this application provide some of this knowledge, primarily based on controlled source seismic methods. Project #1 will derive velocity structure, with higher resolution than currently possible, for the uppermost crust through application of a recently developed method, waveform tomography, to first-arriving waves on vibroseis reflection profiles. Results are interpreted in terms of rock types and may be used to improve computer processing of the full dataset. Project #2 seeks to quantitatively characterize features and develop detailed models of lithospheric boundaries, particularly for the base of the crust, the Moho, to better understand the processes involved in lithospheric development and modification. Representative models of the boundaries are generated, some based on physical models and some through statistical analyses of the properties of observed data. Synthetic data equivalent to the observed data are calculated and comparisons are made. LITHOPROBE is Canada's highly acclaimed national Earth science research project [www.lithoprobe.ca], which is concluding after 22 years. Based on results from across Canada, Project #3A will generate a 6000-km-long lithospheric cross-section from the Pacific to the Atlantic oceans as well as similar cross-sections for NW and NE Canada. These demonstrate the complexity of the processes involved in the evolution of our country. Project #3B will develop a summary of how Canada became the geological collage that it currently represents. A series of illustrations and accompanying text relating to geological domains and tectonic processes will document Canada's evolution from about 4 billion years ago to the present.

北美的岩石圈（地球坚硬的外壳）在过去的40亿年里发展，产生了我们现在看到的地质特征的拼贴画。确定现今岩石圈结构及其在地质时期的形成方式，代表了对“内部空间”的基本认识，这与对“外部空间”的认识同样重要。这些知识也有实际应用：对钻石、贱金属和石油公司有用的区域信息;以及地震为什么和如何发生。本申请中提出的三个项目提供了其中的一些知识，主要基于受控源地震方法。项目1将通过对可控震源反射剖面上的初至波应用最近开发的方法-波形层析成像法，以比目前可能的分辨率更高的分辨率得出最上层地壳的速度结构。根据岩石类型解释结果，并可用于改进完整数据集的计算机处理。项目#2旨在定量描述岩石圈边界的特征并开发详细的模型，特别是对于地壳的底部，莫霍面，以更好地了解岩石圈发展和修改所涉及的过程。生成边界的代表性模型，一些基于物理模型，一些通过对观测数据的属性进行统计分析。计算了与观测数据相当的合成数据，并进行了比较。LITHOPROBE是加拿大备受赞誉的国家地球科学研究项目[www.lithoprobe.ca]，该项目在22年后即将结束。根据加拿大各地的结果，项目#3A将生成从太平洋到大西洋的6000公里长的岩石圈横截面，以及加拿大西北部和东北部的类似横截面。这些都表明了我国演变过程的复杂性。项目#3B将总结加拿大如何成为它目前所代表的地质拼贴画。一系列与地质领域和构造过程有关的插图和文字将记录加拿大从大约40亿年前到现在的演变。