 By 1964 this was Madagascar's second-most valuable export.In 1963, the original Ambindandrakemba mine was exhausted, and the centre was moved north to Betioky, near the Belafa ore body which was thought to have between 2,000 and 5,000 tons of uranothorianite.Mining ended in 1968, due to the degradation of equipment and the discovery of larger deposits in Gabon and Niger.