Seismic imaging of a basaltic Lesser Antilles slab from ancient tectonics.

ABSTRACT: At subduction zones, lithospheric material descends through the upper mantle to the mantle transition zone (MTZ), where it may continue to sink into the lower mantle or stagnate^1,2. Several factors may be important in influencing this flow, including chemical heterogeneity^3-5. However, tight constraints on these mantle flows and the exact factors that affect them have proved challenging. We use P-to-S receiver functions to image the subducting slab and the MTZ beneath the Lesser Antilles subduction zone. We image a singular, superdeep (>700 km) 660-km discontinuity over a 200-km-wide zone within the slab, accompanied by nearby double 660 discontinuity phases (normal and superdeep). Combined geodynamic and waveform modelling shows that this observation cannot be explai

SUBMITTER: Yang X 

PROVIDER: S-EPMC12003162 | biostudies-literature | 2025 Apr

REPOSITORIES: biostudies-literature