NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Ar40-Ar39 systematics in rocks and separated minerals from Apollo 14.The Ar40-Ar39 dating technique has been applied to separated minerals (plagioclase, pyroxene, quintessence and an 'ilmenite' concentrate), and whole rock samples of Apollo 14 rocks 14310 and 14073. Plagioclase shows the best gas retention characteristics, with no evidence of anomalous behavior and only a small amount of gas loss in the initial release. Ages determined from the plagioclase of 14310 and 14073 are (3.87 plus or minus 0.05) and (3.88 plus or minus 0.05) AE respectively. Low apparent ages at low release temperatures, which are frequently observed in whole rock Ar40-Ar39 experiments on lunar basalts, are shown to be principally due to gas loss in the high-K interstitial glass (quintessence) phase, confirming earlier suggestions. The decrease in apparent ages in the high-temperature release previously observed in several total rock samples of Apollo 14 basalts has been identified with the pyroxene. Plagioclase is also found to be the most suitable mineral for the determination of cosmic ray exposure ages, and exposure ages of 280 and 113 m.y. are found for 14310 and 14073, respectively, indicating that these rocks, which are very similar in many respects, have different exposure histories.
Document ID
19730034980
Acquisition Source
Legacy CDMS
Document Type
Conference Proceedings
Authors
Turner, G.
(Sheffield, University Sheffield, United Kingdom)
Huneke, J. C.
Podosek, F. A.
Wasserburg, G. J.
(California Institute of Technology Pasadena, Calif., United States)
Date Acquired
August 7, 2013
Publication Date
January 1, 1972
Subject Category
Space Sciences
Meeting Information
Meeting: Lunar Science Conference
Location: Houston, TX
Start Date: January 10, 1972
End Date: January 13, 1972
Accession Number
73A19782
Funding Number(s)
CONTRACT_GRANT: NGL-05-002-188
Distribution Limits
Public
Copyright
Other

Available Downloads

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