CAREER: Integrating research and education to evaluate Neoproterozoic-Cambrian tectonism and sedimentary basins in western Laurentia

Johns Hopkins University, Baltimore MD

Investigators

Abstract

This project aims to improve understanding of the timing and nature of the breakup of the Neoproterozoic supercontinent of Rodina, a contentious topic that has important implications for coeval changes in ocean chemistry and life. The results of this project will include integrated stratigraphic, geochronological, and geochemical datasets from several regions in western North America. These original datasets will, in turn, be used to generate new subsidence curves for each of these areas. Combined, these products can be used to discriminate between different models that have been proposed for Neoproterozoic–Cambrian rifting on the western margin of the paleocontinent of Laurentia. The synergistic educational plan will focus on improving access to Outdoor Field Work in research and coursework through a tiered mentoring system, development of inclusive field-based courses, and a field forum. The Broader Impacts of this project will focus on empowering underserved populations and broadening participation in the geosciences within Baltimore City through collaboration with the Baltimore Ingenuity Project, a local non-profit which recruits and cultivates middle and high school students with high potential and interest in STEM and from historically underserved populations. The timing and nature of the breakup of the Neoproterozoic supercontinent of Rodinia has remained contentious, with major inconsistencies existing between paleogeographic reconstructions and the geologic records preserved along the western margin of Laurentia, the paleocontinent at the core of Rodinia. Evaluating these divergent interpretations for the tectonic histories of Laurentia’s margins requires significant improvements to the tectonostratigraphic context and age models for Neoproterozoic–Cambrian basin subsidence, rift-related tectonism, and volcanism in western Laurentia, which demand new geochronological constraints and better calibration of unconformities within these sedimentary basins. The research goal of this proposal is to discriminate between different proposed tectonic models for western Laurentia by strategically focusing on the geologic histories of specific Neoproterozoic–Cambrian sedimentary basins located in the western USA, northern Mexico, and British Columbia. These regions are chosen because of their key geographic locations along the margin and because of identified and described bimodal volcanic rocks in these successions. The goals of this project will be achieved by integrating geologic mapping, regional stratigraphy, shale geochemistry, U–Pb geochronology, and subsidence modeling to resolve some of the long-standing debates about rift dynamics in western Laurentia and to improve temporal and geographic models for late Neoproterozoic supercontinent breakup. The proposed scientific research agenda is synergistic with the proposed educational and mentorship plans, which focus on improving access to Outdoor Field Work through: 1) a tiered mentoring system, 2) development and teaching of inclusive field-based courses, 3) a Death Valley Field Forum, and 4) integrated research, mentoring, and Broader Impacts. The project will support cementing a foundation for a career of integrated research and field-based education on studying tectonism, sedimentary basin development, and Earth-life changes in western North America. 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.