U.S. MOHOLE PROJECT

Press, Volume C, Issue 29504, 4 May 1961, Page 20

U.S. MOHOLE PROJECT

Two Striking Achievements

WASHINGTON The outstanding scientific achievement of the United States deep sea drilling project was the discovery that the earth's second layer is composed of basaltic rock. Basalt was previously believed to be the earth's third layer. The outstanding technological achievement of the Project Mohole programme was securing samples from below the ocean floor at depths seven to 10 times deeper than ever before in history. Mr Willard Bascom, Project Mohole director, said that the "programme in the year beginning July 1 will cost about a million dollars, the funds being used to determine the feasibility of going deeper into the earth's crust with improved drilling equipment.” He said that the eventual aim of the programme to drill several miles down to the earth's mantle would take "about another five years and cost 15 million dollars.” The deep ocean drilling was carried out from March 12 to April 12 at a site off Lajolla, California, and near Guadalupe Island off western Mexico in the Pacific Ocean. At Lajolla, five holes were drilled in water 3,140 feet deep. One hole penetrated to 1143 feet, far exceeding world’s records for sub-ocean sampling or coring. At the Guadalupe site, operating in 11.700 feet of water, the drilling vessel sent down a drill 601 feet penetrating 44 feet into the basaltic second layer of the earth. 20m Years Ago The scientists found the soft sediment of the earth below the Guadalupe site to be 560 feet thick and predominantly a grey-green ooze made of 80 per cent, of the microscopic shells of plants and animals. This ooze. Mr Bascom said, was deposited 12m to 20m years ago when sea life in the area was far more prolific than at present. The remaining 20 per cent, of the material is similar to that now being deposited on the ocean floor, he said. The sediment accumulates at the rate of about two centimetres every 1000 years. The second layer encountered for the first time was a hard igneous rock. The composition of this layer had been the subject of years of debate among geologists. Mr Bascom said determining that it is basalt is a "major scientific discovery.” He said the upper few feet are "fragmented and laid with veins of minerals whose age is now being determined.” Immediately above the basalt, he noted, was a layer of white rock, tentatively identified as dolomite. Mr Bascom said another important scientific finding was confirming temperatures deep in the earth’s crust. Temperatures actually taken were close to temperatures theorised by scientists.