The investigators propose to evaluate models for the origin of volcanic lines without age progression by examining the seismic structure of the crust and upper mantle beneath the Cameroon Volcanic Line (CVL). Volcanic lines without age progression cannot be explained by the conventional plume model. One family of models proposes that hot lines can be explained by added complexities within the plume framework, although alternatively lithospheric tensional cracks or small scale convection may explain volcanic lines without age progression. The CVL provides an excellent opportunity to investigate the crust and upper mantle seismic structure of a hot line and provide constraints on the underlying processes generating this feature. To image the seismic structure of the crust and upper mantle beneath the CVL, the PIs will carry out a 21-month passive broadband seismic experiment in Cameroon, using first 8 and then 30 stations. The seismic data will be analyzed by the techniques of body and surface waves tomography, receiver functions, and shear-wave splitting.
