Postdoctoral Fellowship: EAR-PF: Petrochronometers as provenance proxies: implications for the spatio-temporal evolution of continental collision to escape

Megan Mueller博士被授予NSF EAR博士后奖学金，与导师Dr. Mauricio Ibañez-Mejia一起在亚利桑那大学进行研究和教育活动。沉积物源分析在地球科学中被广泛应用于重建古代沉积物扩散网络、源-汇沉积物收支、沉积盆地演化，以及辨别构造、古地理、气候和生物之间的联系。然而，仅研究沉积环境中锆石（ZrSiO4）矿物的年龄分布和化学性质的物源方法在追踪基性岩和变质岩碎屑方面受到限制。这种限制在大陆碰撞环境中尤其明显，在那里，海洋地壳的倒转碎片和挖掘出的变质地块是沉积物的常见来源，但其神秘的物源特征限制了进行精确的地球动力学和古地理重建的能力。本研究探讨了传统与非传统沉积物源方法相结合在土耳其中南部乌鲁基斯拉盆地大陆碰撞向构造逃逸过渡时期沉积物源重建中的适用性。本研究开发了新的、新兴的沉积物源技术的工作流程，这些技术可以应用于世界各地的构造环境，并有助于解决地球科学中的悬而未决的问题。该项目为美国和土耳其的本科生提供实地和实验室培训和研究经验。准确地重建现代和深时间背景下大陆碰撞的时间和动力学仍然是构造界面临的一个关键挑战。然而，越来越多的研究表明，沉积盆地可能保存着最完整的俯冲、增生、碰撞和逃逸记录。利用保存在碎屑矿物中的变形、岩浆和变质信息，从而提供了一种将代理记录统一为碰撞演化整体模型的方法。该项目利用碎屑锆石、金红石和钛矿的U-Pb、Hf、Nd和微量元素组成，追踪火成岩和变质岩源的沉积物源。这项研究将为碎屑岩石年代学应用于沉积盆地分析创造一个概念验证工作流程。此外，这些数据集还建立了岩浆活动、变质作用、变形、地壳厚度和挖掘的时间、速度和空间范围之间的定量关系。利用这种多代理方法，本项目旨在记录大陆碰撞和构造逃逸的时空演变。结果将为今后的沉积物源分析和现代和古代造山带的大陆碰撞背景提供信息。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Dr. Megan Mueller has been awarded an NSF EAR Postdoctoral Fellowship to conduct research and educational activities at the University of Arizona alongside mentor Dr. Mauricio Ibañez-Mejia. Sedimentary provenance analysis is widely used across the Earth sciences to reconstruct ancient sediment dispersal networks, source-to-sink sediment budgets, sedimentary basin evolution, and to discern links between tectonics, paleogeography, climate, and biology. However, provenance methods that exclusively focus on studying the age distributions and chemistry of the mineral zircon (ZrSiO4) in sedimentary environments are limited in tracking detritus sourced from mafic and metamorphic rocks. This limitation is especially pronounced in continental collision settings, where obducted fragments of oceanic crust and exhumed metamorphic massifs are common sources of sediment but whose cryptic provenance signatures impose limits on the ability to perform accurate geodynamic and paleogeographic reconstructions. This research investigates the applicability of combined traditional and non-traditional sedimentary provenance methods to reconstruct sedimentary provenance during the transition from continental collision to tectonic escape in the Ulukisla Basin in south-central Turkiye. This study develops workflows for novel, emerging sedimentary provenance techniques that can be applied to tectonic settings worldwide and aid in addressing outstanding questions in the Earth sciences. The project supports field- and laboratory-based training and research experience for undergraduate students in the United States and Turkiye.Accurately reconstructing the timing and dynamics of continental collisions in modern and deep-time settings remains a key challenge for the tectonics community. However, a growing body of work suggests that sedimentary basins may hold the most complete record of subduction, accretion, collision, and escape. Utilizing the deformational, magmatic, and metamorphic information preserved in detrital minerals thereby provides a way to unite proxy records into a holistic model of collisional evolution. This project leverages the U-Pb, Hf, Nd, and trace element composition of detrital zircon, rutile, and titanite, to track sedimentary provenance from igneous and metamorphic sources. This study will create a proof-of-concept workflow for detrital petrochronology applied to sedimentary basin analysis. Furthermore, these datasets establish quantitative relationships between the timing, tempo, and spatial extent of magmatism, metamorphism, deformation, crustal thickness, and exhumation. Using this multi-proxy approach, this project aims to document the spatial and temporal evolution of continental collision and tectonic escape. The results will inform future work in sedimentary provenance analysis and continental collision settings from modern and ancient orogens.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.