Siderophile Element Evidence Indicates that Apollo 14 High-Al Mare Basalts are Not Impact Melts
Abstract
The high-Al mare basalts from Apollo 14 include most of the oldest individual mare samples known, with Rb-Sr ages in several cases between 4.1 and 4.3 Ga. However, the Nd isotopic systematics for the same samples are generally disturbed, even though under most circumstances Nd isotopes probably tend to be more resistant to disturbance than Sr isotopes. It was suggested by Snyder and Taylor (1996) that the linear arrays on the Rb-Sr diagrams are merely 'errorchrons' caused by mixing of older highland plagioclase with essentially mare-composition impact melt. Besides possibly explaining the isotopic evidence, this model provides a mechanism to engender the unusually high Al content characteristic of this suite of mare basalts.
- Publication:
-
Lunar and Planetary Science Conference
- Pub Date:
- March 1997
- Bibcode:
- 1997LPI....28.1501W
- Keywords:
-
- Lunar Maria;
- Basalt;
- Apollo 17 Flight;
- Hypervelocity Impact;
- Aluminum;
- Magma;
- Melting;
- Neodymium Isotopes;
- Strontium Isotopes;
- Kreep;
- Lunar and Planetary Exploration;
- BASALT: MARE: HIGH-ALUMINUM;
- BASALT: MARE: OLDEST;
- ELEMENTS: SIDEROPHILE;
- ROCKS: LUNAR