CAREER: Deciphering the mechanisms of forearc basin formation by engaging undergraduate and middle school students in field and analytical geoscience research

包含火山链的山脉地带被称为岩浆弧，形成于构造汇聚的边缘，在那里大洋板块正俯冲到大陆或岛弧之下。弧前盆地沿着会聚边缘的岩浆弧向海洋发展，并将沉积物圈闭在深槽中。这些盆地可以存在数千万年到数亿年，作为过去地球环境、过程、气候制度和生命的长期记录。它们还拥有石油和天然气等自然资源。这项研究的目的是通过调查弧前盆地下面的岩石类型与盆地内保存的沉积岩之间的关系来确定弧前盆地的起源。该项目的研究和教育部分侧重于通过持续接触蒙大拿州农村社区中代表性不足的本科生和中学女孩，增加地球科学的多样性和可及性。学生将参与研究设计、实地和实验室工作，以及国家会议。学生们还将帮助领导一个针对中学女生的STEM研讨会，重点是来自美国西部和西藏的岩石和矿物。该项目将解决地球演化中的关键问题，并为传统上对地球科学的参与有限的学生提供机会。由于岩石记录保存不佳或后续变形导致原始构造和地层关系重叠，弧前盆地的形成机制尚未得到很好的了解。这项研究将检验这样一种假设，即弧前地区的下伏基底的伸展提供了一种捕获沉积物和启动盆地沉降的机制，作为弧前盆地形成的先兆。这一假说将通过应用年代学和地球化学方法来验证，以描述基底形成的构造环境、基底-弧前发育的时间和速率以及随后的地质历史。该研究将把野外测绘和沉积学与砂岩岩石学、生物地层学、地质年代学、古地磁学和低温热年代学相结合。野外区域包括加利福尼亚州的大峡谷前弧和西藏的日喀则前弧。每个油田区域在相似但不相同的构造环境中保存了基底和盆地地层学之间的基本关系。该教育计划与研究活动相结合，建立了蒙大拿州立大学沉积本科生研究计划(MSU-SUR)，旨在通过与美洲原住民和第一代大学生的持续接触来扩大地球科学界。密歇根州立大学SUR项目的学生将通过参与文献回顾和实地规划，以及收集和评估数据并传播结果，直接为研究做出贡献。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Mountain belts that incorporate chains of volcanoes, called magmatic arcs, develop at tectonic convergent margins where an oceanic plate is subducting beneath a continent or island arc. Forearc basins develop oceanward of the magmatic arc of a convergent margin and trap sediment in deep troughs. These basins can exist for tens to hundreds of millions of years, serving as a long-term record of past Earth environments, processes, climate regimes, and life. They also host natural resources such as oil and gas. The goal of this research is to determine the origin of forearc basins by investigating the relationship between the types of rocks that underlie the basin and the sedimentary rocks preserved within the basin. The research and education components of this project focus on increasing diversity in, and accessibility to, the geosciences through sustained engagement with underrepresented undergraduate students and middle school girls from rural communities in Montana. Students will participate in research design, field and laboratory work, and national conferences. Students also will help lead a STEM workshop for middle school girls focused on rocks and minerals from the western U.S. and Tibet. The project will resolve critical questions in the evolution of Earth and offer opportunities to students who traditionally have limited participation in the geosciences.The mechanisms of forearc basin formation are not well understood because of poor preservation in the rock record or overprinting of primary tectonic and stratigraphic relationships by subsequent deformation. This research will test the hypothesis that extension of the underlying basement in a forearc region provides a mechanism to trap sediment and initiate basin subsidence as a precursor to forearc basin formation. The hypothesis will be tested by applying chronologic and geochemical methods to describe the tectonic setting of basement formation, timing and rates of basement-forearc development, and subsequent geologic history. The research will combine field mapping and sedimentology with sandstone petrography, biostratigraphy, geochronology, paleomagnetism, and low-temperature thermochronology. Field areas include the Great Valley forearc, California and the Xigaze forearc, Tibet. Each field area preserves primary relationships between basement and basin stratigraphy in similar, but not identical tectonic settings. The education plan integrates with the research activities by establishing the Montana State University Sedimentary Undergraduate Research program (MSU-SUR), which seeks to broaden the Earth Science community through sustained engagement with Native American and first-generation college students. Students in the MSU-SUR program will contribute directly to the research by participating in literature review and field planning, along with collecting and evaluating data and disseminating results.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.