It is found that Apollo 11 low-K and in particular Apollo 17 mare basalts show a wide range of Th/U ratios unlike other rocks; such variations cannot be explained by near surface crystal fractionation. A two-stage fractional crystallization-partial melting model involving a clinopyroxene cumulate as the major phase can explain the variations in Th/U ratios. Due to the Sm-Nd systematics constraint, several source cumulates are invoked to explain the observed Th/U continuum.


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    Title :

    Thorium and uranium variations in Apollo 17 basalts, and K-U systematics


    Contributors:

    Conference:

    Lunar Science Conference ; 1976 ; Houston, TX


    Publication date :

    1976-01-01


    Type of media :

    Miscellaneous


    Type of material :

    No indication


    Language :

    English






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