Contents

16 January 1987
Vol 235, Issue 4786

About The Cover

Triassic sandstone and shale in valley northeast of Ulugh Muztagh, the peak on the horizon and behind the glacier in the middle ground. Note rounded topography near the glacier where Triassic sandstone, siltstone, and shale crop out and the steep topography of the mountain where metamorphic equivalents of these Triassic rocks are more resistant to erosion. See page 299. [Peter Molnar, Massachusetts Institute of Technology, Cambridge, MA 02139]