The majestic slopes of Mount Kilimanjaro. The burning sands of the Ethiopian plateau. The rugged cliffs of the African Rift Valley where Homa sapiens early ancestors thrived millions of years ago. The Comoro Islands where the most ancient of fishes, the coelacanth,is found. All these and many other striking geological features found in north and central Africa are the result of a single giant plume of magma that rose up from Earth's mantle about 45 million years ago and is still present today. That is the conclusion of a geophysical modeling project conducted by Norman H. Sleep, professor of geophysics at Stanford, and Cindy J. Ebinger, lecturer in geophysics at the University of Leeds in the United Kingdom.