| Abstract: | Several Apollo 16 breccias, including one containing goethite, are strikingly enriched in volatile elements such as bromine, cadmium, germanium, antimony, thallium, and zinc. Similar but smaller enrichments are found in all highland soils. It appears that volcanic processes took place in the lunar highlands, involving the release of volatiles including water. The lunar thallium/uranium ratio is 2 x 10-(4) of the cosmic ratio, which suggests that the moon's original water content could not have exceeded the equivalent of a layer 22 meters deep. The cataclastic anorthosites at the Apollo 16 site may represent deep ejecta from the Nectaris basin. |
