Dynamics of Extensional Convergent Margins and the Origin of Supra-Subduction Zone Ophiolites: Hypothesis Testing in the Tonga Forearc

9521023布卢默该项目由俄勒冈州立大学的谢尔曼·布卢默博士主持，旨在支持一次旨在了解西南太平洋汤加俯冲系统发展的研究巡航和随后的数据分析。这种会聚边缘被假设为代表这种俯冲系统的一个简单的末端成员，其中快速的会聚和简单的板块边缘几何形状允许测试关于“弧前”系统的地质演化的一系列假设。该计划将包括研究断层分布的详细海底成像，检查地下建筑的地球物理研究(地震反射、重力和磁学)，以及从地球化学角度检查弧系发展的广泛岩石取样。特别令人感兴趣的将是蛇纹岩底辟的分布和弧系中热液流体迁移的证据。这个项目是与同样在俄勒冈州立大学的道恩·赖特博士合作获得的9521039奖的支持，该博士的支持来自于美国国家科学基金会教师早期职业发展(职业)计划。该奖项支持赖特博士在四年时间里开发海洋和地质科学的跨学科新课程，向本科生和高中生推广科学事业，并在海洋地球物理的不同方面开展双管齐下的研究计划。拟议研究的第一部分侧重于汤加弧前地球物理发展的研究，赖特博士将参加实地方案，她将主要负责对项目期间收集的地球物理数据进行巡航后分析。***

9521023 Bloomer This project by Dr. Sherman Bloomer of Oregon State University supports a research cruise and subsequent data analysis aimed at understanding the development of the Tonga subduction system in the southwestern Pacific. This convergent margin is hypothesized to represent a simple end-member of such subduction systems, where rapid convergence and a simple plate margin geometry allow testing of a series of hypotheses regarding geologic evolution of the "forearc" system. The program will include detailed seafloor imaging to study fault distribution, geophysical studies (seismic reflection, gravity and magnetics) to examine subsurface architecture, and extensive rock sampling to examine the development of the arc system geochemically. Of particular interest will be the distribution of serpentinite diapirs and evidence of hydrothermal fluid migration in the arc system. This project is supported in collaboration with award 9521039 to Dr. Dawn Wright, also at Oregon State University, whose support comes under the NSF Faculty Early Career Development (CAREER) Program. That award provides support for Dr. Wright over four years to develop new, interdisciplinary courses in the marine and geological sciences, to promote scientific careers to undergraduate and high school students, and to carry out a two-pronged research program in different aspects of marine geophysics. The first part of the proposed research focusses on the study of the geophysical development of the Tonga forearc, and Dr. Wright will participate in the field program, and she will have principal responsibility for post-cruise analysis of the geophysical data collected during the project. ***