02 May 1986
Vol 232, Issue 4750

About The Cover

The open ocean is a potential source of cobalt, a strategic metal. Cobalt-rich ferromanganese crusts on the floor of the huge, new United States Exclusive Economic Zone are attracting interest as a potential mineral resource. See page 600. [Photograph courtesy of Dann S. Blackwood, U.S. Geological Survey, Woods Hole, Massachusetts 02543]