The interface between the earth's crust and mantle. Mohorovičić concluded that the earth consists of surface layers above an internal core.

He was the first scientist to establish, based on the evidence of seismic wave behavior, the discontinuity that separates the crust of the planet earth from the mantle.

According to Mohorovičić, a layered structure would explain the observation of depths where seismic waves change speed and the difference in chemical composition between rocks from the crust and those from the mantle.

Andrija Mohorovičić was a Yugoslav geophysicist for whom the Mohorovicic discontinuity was named (1857-1936).