Hotspots and edge-driven convection

Not every hotspot may be related to a deep-mantle plume, and there are a number of examples of intraplate volcanism that have never been suggested to be related to a mantle plume. The mechanism of origin for these intraplate volcanic events remains poorly understood; however, small-scale convection triggered at the edge of a continent or craton is one proposed mechanism. Drawing 600 and 1000 km circles around hotspots, a distance based on the scale-length of convective flow, and looking for circles that intersect cratonic roots discriminates between hotspots that are potentially generated by edge-driven convection and those that are not. The group of hotspots unfavorable for edge-driven convection agrees with other groups of proposed mantle plume hotspots.