05 December 1986
Vol 234, Issue 4781

About The Cover

Remnants of uplifted marine terraces are common in the Southern Alps of New Zealand (bottom). Individual (upper left picture) is collecting widely scattered beach pebbles from an exhumed 320,000-year-old shore platform (altitude 1620 meters) at the base of a degraded sea cliff. Highly rounded quartz pebbles (11 to 12 millimeters in diameter) from notched ridge crest have frosted surfaces and impact marks made in a high-energy sedimentary environment. See page 1225. [W. B. Bull, University of Arizona, Tucson, AZ 85721, and A. F. Cooper, University of Otago, Dunedin, New Zealand]