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
<p><u>Part I</u> 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 t...