I. ANCIENT ARCTIC ICE DOES NOT CONTAIN LARGE EXCESSES OF NATURAL LEAD. II. CHRONOLOGICAL VARIATIONS IN LEAD AND BARIUM CONCENTRATIONS AND LEAD ISOTOPIC COMPOSITIONS IN SEDIMENTS OF FOUR SOUTHERN CALIFORNIA OFF-SHORE BASINS.

摘要

Part I. This study settled the dispute and proved beyond doubt that excess lead today is 300-fold instead of the 5-fold, as proposed by other investigators, greater than prehistoric time. And, virtually all of the present-day excess of lead above natural levels was shown to be caused by indust