Following the procedure outlined by Magnitsky <1971>, thermal profiles of the upper mantle are computed by deriving the thermal gradient from the seismic data given as dvs/d&rgr; used along with the values of (dvs/dT9p and (dvs/dP)T of selected minerals, measured at high temperature. The resulting values of dT/dZ are integrated from 380 km upward toward the surface, where the integrating constant is taken from Akagi and Akimoto's work, T=1400¿C at 380 km. The resulting geotherms for minerals are used to derive geotherms for an eclogite mantle and a lherzolite mantle, with and without partial melting in the low-velocity zone. The geotherms are all subadiabatic, and some are virtually isothermal in the upper mantle. Some are characterized by a large thermal hump at the lithosphere boundary. |