NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
U-Pb geochronology of zircons form lunar Breccia 73217 using a sensitive high mass-resolution ion microprobeU-Pb age determinations on four lunar zircons from existing thin-sections of one highland breccia, 73217, using the recently constructed ion microprobe SHRIMP, are reported. The analytical reproducibility of SHRIMP is demonstrated, and procedures for measuring Pb/U, Th/U, and corecting for initial Pb are explained. Electron microprobe analyses for the zircons are alsoar reported. The results show that the four zircons survived the lunar cataclysm without any identifiable effects on their U-Pb systematics. All four indicate a single age of 4356 +23 or -14 m.y. The zircons have experienced small variable amounts of Pb loss since crystallization, from almost zero up to about 10 percent. If this occurred during one later event, then age of the latter is between 1100 and 2300 m.y.
Document ID
19840043302
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Compston, W.
(Australian National Univ. Canberra, Australia)
Williams, I. S.
(Australian National University Canberra, Australia)
Meyer, C.
(NASA Johnson Space Center Houston, TX, United States)
Date Acquired
August 12, 2013
Publication Date
February 15, 1984
Publication Information
Publication: Journal of Geophysical Research, Supplement
Volume: 89
ISSN: 0148-0227
Subject Category
Lunar And Planetary Exploration
Accession Number
84A26089
Distribution Limits
Public
Copyright
Other

Available Downloads

There are no available downloads for this record.
No Preview Available