Lead isotopic ratios and concentrations have been measured in lavas from the Aleutian volcanic centers of Adak (12) and Atka (12). Whereas lavas from Atka have very small Pb-isotopic ranges (206Pb204Pb = 18.78−18.86; 207Pb204Pb = 15.55−15.62; 208Pb204Pb = 38.31−38.52) those from Adak have ranges nearly twice as large (206Pb204Pb = 18.34−18.86; 207Pb204Pb = 15.47−15.63; 208Pb204Pb = 37.81−38.56). On lead-lead isotopic diagrams, Atka data form tight clusters whereas those from Adaak define a well-developed linear trend extending from the Atka field toward less radiogenic values. At a given 206Pb204Pb, the lavas from both islands plot in the MORB trend for 208Pb204Pb but Atka lavas plot above the MORB 207Pb204Pb-206Pb/204Pb trend and those from Adak fall both within and above the trend.
Geochimica Et Cosmochimica Acta
Myers, James and Marsh, B. D. (1987). "Aleutian Lead Isotopic Data : Additional Evidence for the Evolution of Lithospheric Plumbing Systems." Geochimica Et Cosmochimica Acta 51.7, 1833-1842.