Body Wave Speed Structure of Eastern North America
Date of Original Version
The eastern, passive margin of the North American continent is more heterogeneous than originally envisioned. Imaged by teleseismic body wave arrivals, both compressional Vp and shear Vsh, the lithospheric mantle of the stable, eastern North America contains rapid and large wave speed variations from the fast, older interior toward the slower, margin structures along the continental edge. At multiple regions at the continental edge, wave speeds indicate the presence of a small amount of melt, <1%–2%. Melt assessments were computed using a suite of mineralogical/petrological models to convert Vp and Vsh into absolute temperatures and melt fraction. Moreover, along the Atlantic margin, wave speeds are lower than expected for a previously rifted margin. Within the continent interior, wave speeds in the mantle lithosphere vary spatially at wavelengths, suggesting strong compositional and mineralogical influence likely a result of later stage alteration from volatile rich fluids.
Publication Title, e.g., Journal
Geochemistry, Geophysics, Geosystems
Savage, Brian. "Body Wave Speed Structure of Eastern North America." Geochemistry, Geophysics, Geosystems 22, 1 (2021). doi: 10.1029/2020GC009002.