Impact glasses from the Apollo 14 landing site and implications for regional geology

[1] Lunar impact glasses possess the unmodified refractory element ratios of the original fused target materials at the sites of impacts. These target materials are regolith developed on different terrains and local rock types. Almost 800 glasses from the Apollo 14 landing site have been analyzed by electron microprobe in this study. These glasses show significant variation and hint at the existence of multiple terrains of differing compositions near the landing site. To test this idea, we have used Clementine color image data to construct iron and titanium maps from which a petrologic map in an elemental system analogous to the sample database was made. This map shows the regional provenance of Apollo 14 samples and suggests that the highlands in the Fra Mauro region of the Moon consist of a potassium, rare Earth element, and phosphorus (KREEP)-rich, basaltic debris layer that overlies a more feldspathic terrain in some areas. This mapping effort demonstrates the efficacy of using Clementine image data to place lunar sample information into a regional, and ultimately global, context. Lunar impact glasses and orbital data can provide geochemical constraints on the local and regional geology of the Moon.