Mantle plumes are blobs of relatively hot, low-density mantle that because of their buoyancy, rise through the surrounding mantle. The existence of mantle plumes in the Earth was first suggested in 1963 by J. Tuzo Wilson at the University of Toronto as an explanation of oceanic island chains, such as the Hawaiian and Emperor volcanic chains, which change progressively in age along the chain. Wilson proposed that as lithospheric plates move over fixed hot spots (the mantle plumes), volcanism is recorded as a linear array of volcanic seamounts and islands parallel to the direction the plate is moving.
In 1971, W. Jason Morgan at Princeton University suggested that flood basalts were formed by the melting of plume heads, whereas hot spot volcanic chains were derived from partial melting of plume tails. He also showed that closely spaced hot spots on the same plate had not moved significantly relative to each other, and he suggested this was evidence that the plumes had come from the core-mantle boundary.