Contents

07 May 2004
Vol 304, Issue 5672

About The Cover

Cover image expansion

COVER Crystal structure of Earth's deep mantle. Coordination polyhedra of oxygen atoms (white) around silicon atoms are shown as octahedra; magnesium ions are in yellow. Experiments simulating the high pressure and temperature of the deep Earth yield a new view of the lowest 200 to 300 kilometers of mantle, as described on page 855. [Image: M. Murakami]