Pristine moon rocks - Apollo 17 anorthositesNew chemical analyses and petrographic descriptions for 10 previously unanalyzed Apollo 17 rock samples are provided. Attention is focused on several that appear to be pristine. All samples were analyzed in INAA using a procedure based on that of Kallemeyn et al. (1989). One sample was found to be unambiguously pristine, and is the first pristine ferroan-anorthositic suite (FAS) sample from Apollo 17. It exhibits extremely low-mg(asterisk) mafic silicates, coupled with relatively sodic plagioclase. It has an unusually high augite/low-Ca pyroxene ratio and contains incompatible trace elements at levels unprecedentedly high compared to FAS anorthosites from the Apollo 14, 15, 16 sites. It is inferred that 74114.5, and Apollo 17 anorthosites in general, formed at a relatively late stage in the evolution of the primordial magmasphere.
Document ID
19910057713
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Warren, P. H. (California Univ. Los Angeles, CA, United States)
Jerde, E. A. (California Univ. Los Angeles, CA, United States)
Kallemeyn, G. W. (California, University Los Angeles, United States)