Stock Photo - Apr. 04, 1968 - These basaltic glass samples have revealed new evidence that the ocean floor is expanding, gradually moving North and South America farther away from Europe and Africa. The samples were dredged up from te Mid-Atlantic Ridge, an underwater formation (actually two ridges separated by a valley) running down the center of the Atlantic Ocean, by an oceanographic expedition sponsored by the Department of Energy, Mines, and Resources, Government of Canada. By determining the ages of these rock samples, scientists at the General Electric Research and Development Center showed that rock ages increase with distance from the valley. The sample at right, recovered from the center of the valley, turned out to be about 13,000 years old. The sample at left, taken more than four miles from the center of the valley, was about 290,000 years old. Other rock samples, recovered from points 10 miles and 36 miles from the center of the valley, were determined by Geological Survey of Canada scientists to be 740,000 and 8,000,000 years old, respectively. This new evidence supports the widely-discussed theory that all the continents were oce joined into a single land mass that gradually split up and drifted apart. (Credit Image: © Keystone Press Agency/Keystone USA via ZUMAPRESS.com)