Thorium and uranium variations in Apollo 17 basalts, and K-U systematicsIt 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.
Document ID
19770051889
Acquisition Source
Legacy CDMS
Document Type
Conference Proceedings
Authors
Laul, J. C. (Battelle Pacific Northwest Labs. Richland, WA, United States)
Fruchter, J. S. (Battelle Pacific Northwest Laboratories Richland, Wash., United States)