Lead isotopes in volcanic rocks and possible ocean-floor thrusting beneath island arcs

Earth and Planetary Science Letters
By:

Links

Abstract

The isotopic composition of lead in the Japanese primary basalts gradually decreases in radiogenic character in a transverse from the Pacific Ocean side to the Japan Sea side, whereas the observed 238U204Pb and 232Th204Pb ratios in the basalts increase in the same direction. The isotopic composition of lead suggests that tholeiite (Pacific side) is generated at a shallower depth than alkali basalt (Japan Sea side) as postulated by Kuno. The inverse correlation of the 238U204Pb with the 206Pb204Pb ratios could be due to preferential Pb extraction with respect to uranium at shallow depths. Alternatively, these geochemical results can be interpreted in terms of the Pacific oceanic rigid plate being underthurst beneath the island arc. The isotopic variation in basalts across the Japanese island arc would result from different proportions of the plate material and the upper mantle of continental side in the partial melt.

    Publication type Article
    Publication Subtype Journal Article
    Title Lead isotopes in volcanic rocks and possible ocean-floor thrusting beneath island arcs
    Series title Earth and Planetary Science Letters
    DOI 10.1016/0012-821X(69)90187-3
    Volume 6
    Issue 5
    Year Published 1969
    Language English
    Publisher Elsevier
    Description 8 p.
    First page 369
    Last page 376
    Google Analytic Metrics Metrics page
    Additional publication details