Natural Remanent Magnetization Studies of a Layered Breccia Boulder from the Lunar Highland Region
Abstract
The average directions of natural remanent magnetization (NRM) of three texturally distinct layers (72215, 72255, and 72275) of a 2 m-sized breccia boulder were found to be the same, while the directions of their stable components of NRM were found to be widely divergent. One clast from 72275 yielded a stable NRM direction which was different from that of the matrix. Approximate paleointensity measurements showed that 72255 and 72275 could have obtained their stable remanence from an ancient magnetic field of the same magnitude. However, 72215 probably was magnetized by a magnetic field of a different intensity. We concluded that the coincident NRM directions owe their origin to a secondary imprint of less stable magnetization imparted during the assembly of the boulder at moderate temperatures (∼ 450°C) on the South Massif. The stable directions, on the other hand, date from the last, higher-temperature (∼ 770°C) magnetizing event experienced by the mineral and lithic components while they were part of the immature pre-Serenitatis regolith.
- Publication:
-
Moon
- Pub Date:
- December 1975
- DOI:
- Bibcode:
- 1975Moon...14..473B
- Keywords:
-
- Breccia;
- Lunar Rocks;
- Magnetization;
- Remanence;
- Apollo 17 Flight;
- Flux Density;
- Lunar Composition;
- Lunar Landing Sites;
- Lunar Magnetic Fields;
- Magnetic Flux;
- Surface Layers;
- Lunar and Planetary Exploration