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Shapefiles of ancient and modern passive margins for the world

Published by U.S. Geological Survey | Department of the Interior | Metadata Last Checked: January 27, 2026 | Last Modified: 2025-03-31T00:00:00Z
Two shapefiles mapping the locations of ancient and modern passive margin boundaries are presented. These data are a digital recreation of the work originally published by Bradley (2008). The ancient passive margin data were used as an evidential layer to map prospectivity for sediment-hosted Pb-Zn mineral systems (Lawley and others, 2022). The ancient passive margins dataset includes additional attributes related to the boundary's orogenic setting and history, the length of the boundary, its estimated lifespan, and its modern-day country location. Although only ancient passive margin boundaries were analyzed for the United States, Canada, and Australia for this study, boundaries for the world are included in the shapefile. The modern passive margin dataset includes an identifier for the margin segment, a margin name, the associated ocean, and age ranges of basin initiation, mean age and length of the respective passive margin segment. The modern passive margin data were not used in prospectivity modeling for ancient deposits. The passive margin boundaries in both files are mapped as line segments in geographic coordinates using a WGS84 datum. References Bradley, D.C., 2008, Passive margins through earth history: Earth-Science Reviews, v. 91, no. 1-4, p. 1-26, https://doi.org/10.1016/j.earscirev.2008.08.001. Lawley, C.J.M., McCafferty, A.E., Graham, G.E., Huston, D.L., Kelley, K.D., Czarnota, K., Paradis, S., Peter, J.M., Hayward, N., Barlow, M., Emsbo, P., Coyan, J., San Juan, C.A., and Gadd, M.G., 2022, Data-driven prospectivity modelling of sediment-hosted Zn-Pb mineral systems and their critical raw materials: Ore Geology Reviews, v. 141, no. 104635, https://doi.org/10.1016/j.oregeorev.2021.104635.

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