Collaborative research: investigating eocene ARC initiation during plate reorganization from geologic observations and analysis from southern alaska

The National Science Foundation Office of Integrative Activities awarded Bucknell University $376,648 on August 1, 2026, for collaborative research investigating Eocene arc initiation during plate reorganization in southern Alaska, under the Geosciences program (CFDA 47.050).

The research team will collect sedimentologic, structural, and geochemical field data from the Aleutian-Meshik Arc and forearc basin on the Alaska Peninsula to determine the spatial-temporal evolution of Paleocene–Eocene subsidence, magmatism, and deformation, and to decipher linkages between upper-plate processes and approximately 50-million-year-old Pacific-wide plate reorganization models associated with initiation of the Alaska-Aleutian subduction zone. Field methods include collection of bedrock and modern river sand samples. Results will be disseminated through academic presentations and papers, and public talks in rural Alaskan villages and Katmai National Park to promote awareness of geohazards and mineral and energy resources in Alaska.

Performance is based at Bucknell University in Lewisburg, Pennsylvania, with a period of performance from August 1, 2026, through July 31, 2029.

Abstract

Subduction zones are the most hazardous and critical mineral-rich locations on earth. This study will provide geological data that will directly enhance the ongoing assessment of geohazards and resources (oil/gas, geothermal energy, and critical minerals) in alaska. In addition, the alaska peninsula, is one of the most earthquake-prone regions in north america. Large earthquakes and volcanic eruptions occur in this region and pose a significant threat to cities and communities in western and south-central alaska. This project aims to understand the role and timing of faulting and magmatism have in the development of the region. Results from this project will be disseminated via presentations and papers, and public talks in rural alaskan villages and katmai national park. These activities will promote public awareness of the importance of scientific research towards societally relevant issues, including geohazards as well as mineral and energy resources. Formation of new subduction zones is infrequent and occurs underwater, making the process challenging to investigate and thus poorly understood. This multidisciplinary study will examine the geological evolution of the ~50- to 25-million-year-old aleutian-meshik ARC and forearc basin on the alaska peninsula to better understand how magmatism and deformation evolve during subduction initiation. The research team will collect detailed sedimentologic and structural field data, and bedrock and modern river sand samples to 1) determine the spatial-temporal evolution of paleocene?eocene subsidence, magmatism, and deformation in the greater forearc region, and 2) decipher linkages between upper-plate processes and CA. 50-million-year old pacific-wide plate reorganization models that incorporate the initiation of the alaska-aleutian subduction zone. Field methods include collection and synthesis of robust outcrop fault kinematic datasets, targeted geologic mapping of igneous, sedimentary, and hydrothermal rocks, construction of cross-sections, and detailed stratigraphic characterization of sedimentary strata. Analyses of collected samples will include major and trace element geochemistry and isotope compositions from igneous bedrock, lavas, tuffs, tuffaceous sandstones, and modern river sediment, and apatite fission-track thermochronology. This multidisciplinary research will provide new constraints on the upper-plate response to subduction initiation across the alaska peninsula, and more broadly, shed light on the structural, geochemical, and sedimentologic processes associated with the early development of a subduction zone and the greater forearc region and its resources. 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.- subawards are planned for this award.