We predict the insulator-metal-insulator transitions for the temperature and pressure of the lower mantle with the metal layer thickness km at the depth of 1400-1800 km. The insulator-metal transition has the Mott-Hubbard origin, while the second transition from metal to insulator results from spin crossover of the Fe2+ ions from high spin S=2 to low spin S=0 state. The conductivity in the metal layer may attain 250 S/m. The depth profile of the conductivity is also suggested
