The melting temperature of (Mg,Fe)SiO3 perovskite, the dominant mineral phase of the Earth's lower mantle, has been measured to a pressure of 90 (¿10) GPa. Below 60 GPa we find good agreement with the previous measurement of Heinz and Jeanloz [1987a>, and above 60 GPa the melting curve of silicate perovskite has a small positive slope of 19.5(¿5.5) K/GPa. The melting point of (Mg0.9Fe0.1)SiO3 perovskite is 3800 (¿300)K at 96 GPa; by extrapolation to 136 GPa, it is 4500(¿500)K at the core-mantle boundary. These values provide an upper limit to the geotherm through the solid mantle, and they are compatible with recent estimates of the temperature in the core being high (~4500 K at the core-mantle boundary). Our melting curve implies that the volume change on melting increases at 60 GPa from ΔVm=0.0(¿0.2) cm3/mole to ΔVm≂0.16 (¿0.03) cm3/mole. We derive an equation of state for the melt from our data, and find that a highly coordinated structure is required to explain the molar volume of liquid (Mg,Fe)SiO3 at pressures above ~20GPa. ¿ American Geophysical Union 1989