IMPINGEMENT OF MANTLE PLUMES ON THE LITHOSPHERE - CONTRAST BETWEEN EARTH AND VENUS

The penetration, ascent, melt production, cooling and solidification of a mantle plume as it impinges on the base of the lithosphere are modelled as functions of the lithospheric temperature and thickness. The models indicate that, if mantle and plume temperatures and plume dimensions of Venus are similar to those of Earth, the higher lithospheric temperature of Venus causes higher ascent of plumes into the lithosphere and a greater amount of lithospheric melting. However, the rates of intraplate volcanism on Venus and Earth appear to be similar, indicating that mantle or plume temperatures may be less or plumes may be smaller in Venus than in Earth.