Collaborative Research: Suturing the Heart of Asia: Tectonics of the Mongol-Okhotsk Ocean Closure

合作研究：缝合亚洲心脏：蒙古-鄂霍次克洋闭合的构造

• 批准号: 1917645
• 负责人: Cari Johnson
• 金额: $ 67.21万
• 依托单位: University of Utah
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-08-01 至 2024-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1917645&HistoricalAwards=false
• 关键词: Collaborative; Research; Suturing; Heart; Asia

The closure of ocean basins and formation of supercontinents throughout geologic history have directly influenced the distribution of natural hazards and natural resources. Changes in the distribution of ocean basins and land masses have also impacted the history of Earth's climate and the evolution of life. The modern-day continent of Asia consists of remnants of old continents, relict ocean basins, and fragments of island chains assembled over hundreds of millions of years. The ancient Mongol-Okhotsk Ocean was one of the largest oceans that previously separated fragments of the present core of the Asian continent, and yet remarkably little is known about it. This study examines the timing and mechanisms of the closure of the Mongol-Okhotsk Ocean through a multidisciplinary approach that includes field mapping and dating of key rock types. The project supports collaborations between diverse scientists from universities in the US and Mongolia, and training and mentoring of US and Mongolian students. Outreach efforts associated with this project include new educational resources for US and international students, along with new educational modules on plate tectonics, supercontinents, and geologic time for secondary school students.This project integrates stratigraphic, paleomagnetic, structural, and geochronologic datasets for the Mongol-Okhotsk suture that are assessed in the context of competing end-member hypotheses regarding modes of ocean basin closure and continental collision, such as major oroclinal bending as compared with scissor-like suturing. The project also investigates the role of strike-slip faulting during ocean closure and its relationship to subsequent orogenic collapse. Research outcomes are multidisciplinary and include: 1) stratigraphic analyses to document marine-nonmarine facies transitions and better delineate subtypes of remnant ocean basins; 2) structural datasets that document deformation in the nominal western hinge zone near the Hangay Dome; 3) verification of existing low-volume paleomagnetic data sets and new reference poles to improve APWP comparisons; and 4) development of an overarching geochronologic framework for key rock types. The project includes collaboration with international teams focused on regional magmatism and metallogeny.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

整个地质历史中洋盆的闭合和超级大陆的形成直接影响了自然灾害和自然资源的分布。海洋盆地和陆地分布的变化也影响了地球气候的历史和生命的进化。现代亚洲大陆由旧大陆的残余物、残留的洋盆以及数亿年来聚集的岛链碎片组成。古代蒙古鄂霍次克洋是最大的海洋之一，以前将亚洲大陆核心的碎片分开，但人们对它知之甚少。这项研究通过多学科方法研究了蒙古-鄂霍次克洋闭合的时间和机制，包括对关键岩石类型进行现场测绘和测年。该项目支持来自美国和蒙古大学的不同科学家之间的合作，以及对美国和蒙古学生的培训和指导。与该项目相关的外展工作包括为美国和国际学生提供新的教育资源，以及为中学生提供有关板块构造、超大陆和地质时间的新教育模块。该项目集成了蒙古的地层、古地磁、结构和地质年代数据集-在有关洋盆闭合和大陆碰撞模式的竞争端元假设的背景下评估鄂霍次克缝合线，例如与剪刀状缝合线相比的主要口斜弯曲缝合。该项目还研究了走滑断层在海洋闭合过程中的作用及其与随后的造山崩塌的关系。研究成果是多学科的，包括：1）地层分析，记录海洋-非海洋相的转变，并更好地描绘残余洋盆的亚型； 2) 记录杭爱圆顶附近名义西部铰链区变形的结构数据集； 3）验证现有的低容量古地磁数据集和新的参考极，以改进APWP比较； 4) 开发关键岩石类型的总体地质年代学框架。该项目包括与专注于区域岩浆作用和成矿作用的国际团队的合作。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。