Birch predicted in 1952 that major phase changes happen at certain critical depths in the upper mantle.

Bundy and Al realised in 1955 the first synthesis of diamond at very high pressure.

Weir and Al invented in 1959 the diamond anvil cell which will be used for very higher pressure and temperature studies at laboratory.

Ringwood and Major realised in 1966 an experimental demonstration of the olivine-spinel transformation which they could correlate with the seismic discontinuity observed in the mantle at the depth of 400km.

Akimoto and Fujisawa performed in 1966 the experimental demonstration of the olivine-spinel transformation for iron rich mineral compositions.

Meyer and Boyd realised in 1969 the first analyses of inclusions in diamonds.