New Insights Into Lithospheric Structure and Melting Beneath the Colorado Plateau

The Colorado Plateau and its surroundings serve as an archetypal case to investigate the interaction of mantle melting processes lithospheric structure. It has been hypothesized that widespread Cenozoic volcanism indicates encroachment convective upwelling asthenosphere toward center. In this study, we generate a Common Conversion Point (CCP) stack S-to-p (Sp) receiver functions image locations discontinuities in southwestern United States. Our results are broadly similar prior work, showing strong continuous Negative Velocity Gradient (NVG) consistent with Lithosphere-Asthenosphere Boundary (LAB) over much study area. However, several methodological improvements, able obtain more reliable NVG depth picks below where LAB becomes weaker, deeper, broader. We compare inferred topography NVGs volcanoes, find majority recent volcanoes co-located lithosphere is ∼80 km thick. This appears be critical at which partial melt from pooling base (or within) may percolate surface. our CCP profiles magma equilibration conditions determined petrologic analysis good agreement between equilibration. provides insight into progression magmatism loss center Plateau, demonstrates how small-scale like influence lithosphere-asthenosphere interactions persist large temporal spatial scales.