Engineering topics
Publications and source records attributed to Heiken, Grant H..
The present status of lunar knowledge based on U.S. and USSR lunar missions and the continuing analysis of lunar samples and data is reviewed. Particular attention given to exploration, samples, and recent concepts of the moon; the lunar environment; lunar surface processes; the lunar minerals, rocks, and regolith; chemical elements in the moon; physical properties of the lunar surface; and global and regional data about the moon.
This workshop on lunar mare volcanism was the first since 1975 to deal with the major scientific advances that have occurred in this general subject, and the first ever to deal specifically with volcanic glasses. Lunar volcanic glasses are increasingly being recognized as the best geochemical and petrologic probes into the lunar mantle. Lunar volcanic glasses, of which 25 compositional varieties are presently known, appear to represent primary magmas that were produced by partial melting of differentiated mantle source regions at depths of perhaps 400 to 500 km. These high-magnesian picritic magmas were erupted onto the lunar surface in fire fountains associated with the release of indigenous lunar volatiles. The cosmic significance of this volatile component, in an otherwise depleted Moon, remains a lingering puzzle. The resource potential, if any, of the surface-correlated volatile sublimates on the volcanic glass spherules had not been systematically addressed prior to this workshop.
Compositional (by INAA) and petrographic studies were performed among the smaller rocks (not analyzed previously) from the Apollo 14, 16, and 17 sites as part of a search for regolith samples exotic to the small traverse areas associated with these missions. Of the 40 samples studied, 31 were regolith breccias. Among these, three of the Apollo 14 samples proved to be compositionally unique, particularly the 14315 sample, which is radically different from all other Apollo 14 regolith materials (lower Mg and Fe, far higher Al and far lower REE abundances), and is probably exotic to the Apollo 14 traverse area. Among 10 samples from Apollo 17, all but one proved to be typical Apollo 17 regolith breccia. However, the 72504,10 sample is more than 99 percent pure pyroclastic glass, compositionally identical to the Apollo 17 orange glass obtained at a location 4 km away, attesting to the widespread distribution of orange glass deposits.