CAREER: Exhumation of a High-Grade Metamorphic Terrane, and Late-Stage Orogenic Collapse in the Southeastern New England Appalachians

职业生涯：新英格兰东南部阿巴拉契亚山脉高级变质地体的剥露和晚期造山崩塌

• 批准号: 1052458
• 负责人: Yvette Kuiper
• 金额: $ 49.61万
• 依托单位: Boston College
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-06-01 至 2012-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1052458&HistoricalAwards=false
• 关键词: CAREER; Exhumation; Grade; Metamorphic; Terrane

The Appalachians are a composite mountain belt consisting of various microcontinents, oceanic and continental volcanic arcs and (meta)sedimentary domains that collided during the Appalachian mountain building events. Geological investigations in the Appalachian commonly emphasize the amalgamation history of the various terranes. This proposal focuses on the syn- to post-collisional exhumation history of the deeper domains, as well as late-stage collapse of the mountain belt, to gain fundamental insights into late- to post-mountain formation processes in the northern Appalachians and beyond. Research is carried out in the southeastern New England section of the Appalachians through a strongly integrated research and educational plan.The southeastern New England Appalachians generally consist of three terranes. From west to east they are the Merrimack, Nashoba and Avalon terranes. The Nashoba terrane is bounded by moderately NW-dipping faults. Preliminary field data suggest that deeper domains within the Nashoba terrane may have extruded towards the east, based on fold geometries, metamorphic characteristics and the apparent relationship between approximately 395 million year melts in the Nashoba terrane and approximately 395 million year intrusions in the structurally overlying Merrimack terrane. Furthermore, preliminary field observations indicate that most inter- and intra-terrane shear zones show evidence for late low-grade normal movement, presumably related to late-stage mountain collapse. The purpose of this research is to investigate both the high-temperature and low-temperature exhumation and collapse mechanisms through a combination of field mapping, detailed structural analysis and cutting-edge radiometric dating techniques.Integration of research and field work into the undergraduate student experience is central to this project. Students from various geoscience departments in the Boston area are encouraged to participate and collaborate through a Geological Field Research course, giving them an excellent opportunity to discuss research with their peers and creating a stronger community. Subsequent thesis research by undergraduate and MS students involves analytical work at Boston College, MIT and UMass Amherst, strengthening the relationship between the three labs and between students and faculty. Students, especially women and minority students, are encouraged to participate through existing courses, departmental advising activities and other geoscience departments. Students from underrepresented groups are reached through the Boston College AHANA (African-American, Hispanic, Asian and Native American) student office and the McNair program for undergraduates who are low-income and first-generation college participants, and/or part of underrepresented groups. Funding for this project is provided by the NSF EAR Tectonics Program, with support from the NSF EAR EarthScope and Education and Human Resources Program.

阿巴拉契亚山脉是一个复合山脉带，由各种微大陆、海洋和大陆火山弧以及阿巴拉契亚造山事件期间碰撞的（变）沉积域组成。阿巴拉契亚山脉的地质调查通常强调各种地体的合并历史。该提案重点关注更深区域的同碰撞后折返历史，以及造山带的后期塌陷，以获得对阿巴拉契亚山脉北部及其他地区的晚期至后山形成过程的基本见解。研究是通过一个强有力的综合研究和教育计划在阿巴拉契亚山脉新英格兰东南部进行的。新英格兰东南部阿巴拉契亚山脉通常由三个地体组成。从西到东分别是梅里马克地体、纳肖巴地体和阿瓦隆地体。 Nashoba 地体以中度向西北倾斜的断层为界。初步现场数据表明，根据褶皱几何形状、变质特征以及纳肖巴地体中大约 3.95 亿年的融化与上覆梅里马克构造中大约 3.95 亿年的侵入之间的明显关系，纳肖巴地体内的更深区域可能已向东挤压。地体。此外，初步实地观察表明，大多数地体间和地体内剪切带显示出晚期低级正常运动的证据，可能与晚期山体崩塌有关。本研究的目的是通过结合现场测绘、详细结构分析和尖端辐射测年技术来研究高温和低温折返和塌陷机制。将研究和现场工作融入本科生的体验中是这个项目的核心。鼓励来自波士顿地区各个地球科学系的学生通过地质实地研究课程参与和合作，为他们提供了与同行讨论研究并创建更强大社区的绝佳机会。本科生和硕士生的后续论文研究涉及波士顿学院、麻省理工学院和麻省大学阿默斯特分校的分析工作，加强了三个实验室之间以及学生和教师之间的关系。鼓励学生，特别是女性和少数民族学生参与现有课程、部门咨询活动和其他地球科学部门的活动。通过波士顿学院 AHANA（非裔美国人、西班牙裔、亚洲人和美洲原住民）学生办公室和针对低收入和第一代大学参与者和/或属于代表性不足群体的本科生的 McNair 计划，接触来自代表性不足群体的学生。该项目的资金由 NSF EAR 构造计划提供，并得到 NSF EAR EarthScope 以及教育和人力资源计划的支持。