Hotspot tracks in the South Atlantic located above bands of fast flowing asthenosphere driven by waning pulsations from the African LLSVP

The location and crustal structure of hotspot tracks in the South Atlantic reflect
where melts related to sluggishly flowing plume material can reach the plate surface. This
raises the paradox of how long-lived, age progressive hotspot tracks can arise in the
absence of closely spaced, narrow mantle plumes. Here we show that young hotspot trails in
the southern South Atlantic are located above bands of seismically slow material in the
asthenosphere, which we interpret as channels of fast-flowing asthenosphere fed by a large
scale plume upwelling from the African LLSVP. A broad region of seismically slow
asthenosphere in the vicinity of Paraná continental flood basalts may be indicative of a long-
lived, large scale plume under the South American plate. We propose that hotspot tracks
developed above fast flow channels in the asthenosphere that evolved between these …