Collaborative Research: RUI: An undergraduate cohort thermochronology research and mentorship experience investigating the thermo-tectonic record of the northern Klamath Mountains

合作研究：RUI：本科生群体热年代学研究和指导经验，调查克拉马斯山脉北部的热构造记录

• 批准号: 2242862
• 负责人: Francis Sousa
• 金额: $ 17.26万
• 依托单位: Oregon State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-07-01 至 2026-06-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2242862&HistoricalAwards=false
• 关键词: Collaborative; Research; RUI; undergraduate; cohort; Collaborative; Research; RUI; undergraduate; cohort

The geologic history of mountain building events is chronicled in the rock record, especially along former tectonic plate boundaries. Approximately 56 million years ago, a large basaltic oceanic plateau, the Siletzia-Crescent terrane, erupted off what is now the coast of the Pacific Northwest. A few million years after eruption, it collided with North America, and is proposed to have caused i) tectonic plate rotations, ii) mountain building and major regional-scale faulting, and iii) the subduction zone plate boundary to jump westward, establishing the modern Cascadia subduction zone. Today, the southern edge of Siletzia-Crescent terrane collision is preserved as a sliver of basaltic rock thrust on older sedimentary rocks in southern Oregon. Few syn-collisional sedimentary rocks survive from the time of Siletzia collision, rendering direct investigation of the effect of the collision challenging. To overcome this challenge, the investigators will target specific minerals in older, crystalline rocks from the northern Klamath Mountains, located south of the collision suture. Using this approach, the research team will reconstruct the burial, thickening, uplift, and erosion history of the region in response to collision. Geochemical analysis of these mineral chronometers is an application commonly used to address large scale tectonics questions, however, the advanced technique is typically available only to scientists at large, primarily research-oriented institutions. In this project, the principal investigators will center a group of undergraduate researchers at Cal Poly Humboldt and Oregon State University, locations that straddle the geologic region of interest, to reconstruct the tectonic history of the southern Siletzia-North American collisional zone, by applying multiple mineral chronometers, in a collaborative, academic-year, cohort-based undergraduate research experience. Siletzia formation and subsequent accretion marks a major shift in western U.S. subduction tectonics. The timing of Siletzia collision is coincident with the shut off of Farallon slab subduction and predates the formation of the modern Cascadia subduction zone and arc. The Siletzia terrane comprises the basement rock over a 600 km stretch of western North America from Roseburg, OR to Vancouver Island. However, the spatial and thermal impact of Siletzia accretion on the North American continent is not well understood, largely due to a missing and overprinted geologic and thermal record. The investigators will center undergraduate student research contributions through a novel, year-long, comprehensive cohort experience. The research team will apply multi-method mid- and low-temperature thermochronometry to northern Klamath Mountain samples to assess the continent’s response prior to, during, and following Siletzia accretion. Results will address a major knowledge gap in regional evolution of the Cascadia Subduction Zone, have implications for the thermal and spatial magnitude and rate of exhumation, burial, and deformation driven by accretion tectonics on overriding continental plates, address challenges resolving tectonic and landscape evolution events that are missing from the rock record using multi-method thermochronometry, and engage undergraduate students as primary research contributors guided by three Principal Investigators with overlapping expertise.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.

山地建筑事件的地质历史记录在摇滚记录中，尤其是沿着以前的构造板界。大约5600万年前，一个大型的玄武岩大型高原，西米尔兹式的地层，爆发出了现在太平洋西北的海岸。爆发几百万年，它与北美相撞，并被提议引起i）构造板旋转，ii）山区建筑和主要区域尺度断层，以及iii）俯冲带板块边界向西跳跃，建立了现代的卡斯卡迪亚俯冲区。如今，Siletzia Cresscent Terrane碰撞的南边缘被保存为一块玄武岩岩石，俄勒冈州南部的较老的沉积岩石上推了。很少有合成沉积岩石从Siletzia碰撞时期生存下来，从而直接研究了碰撞挑战的影响。为了克服这一挑战，调查人员将针对来自碰撞成功以南的北克拉马斯山脉的较老的晶体中的特定矿物。使用这种方法，研究小组将根据碰撞重建该地区的埋葬，增厚，隆起和侵蚀历史。对这些矿物天文计时器的地球化学分析是一种通常用于解决大规模构造问题的应用程序，但是，高级技术通常仅适用于大型，主要研究的机构的科学家。 In this project, the principal investigators will center a group of undergraduate researchers at Cal Poly Humboldt and Oregon State University, locations that straddle the geologic region of interest, to reconstruct the tectonic history of the Southern Siletzia-North American Collisional Zone, by applying multiple mineral chronometers, in a collaborative, academic year, cohort-based undergraduate research experience. Siletzia的形成和随后的积聚标志着美国西部俯冲构造的重大转变。 Siletzia碰撞的时机与Farallon平板俯冲的关闭相吻合，并呈现了现代Cascadia俯冲带和ARC的形成。 Siletzia Terrane从罗斯堡（Roseburg）或温哥华岛（Vancouver Island）延伸了600公里的北美西部600公里。然而，对北美大陆的Siletzia积聚的空间和热影响尚不清楚，这在很大程度上是由于缺失和刻有层次的地质和热记录所致。调查人员将通过新颖，一年，全面的队列经验以学生的研究贡献为中心。研究小组将对北部克拉马斯山样本进行多方法中和低温热相关，以评估持续，期间，之中和之后的siletzia积聚的响应。结果将解决卡斯卡迪亚俯冲区区域演变中的主要知识差距，对由覆盖板上的积分构造构成构造所驱动的热量和空间和空间幅度以及灌输，埋葬和变形率具有影响该奖项在三名主要研究人员的指导下。该奖项反映了NSF的法定任务，并通过使用基金会的知识分子优点和更广泛的影响标准来评估，被认为是宝贵的支持。