Provenance of KREEP and the exotic component - Elemental and isotopic studies of grain size fractions in lunar soilsSieve fraction analyses of lunar soils reveal the presence of a fine-grained exotic component enriched in K, Rb, Sr, Ba, and in radiogenic Sr in all soils. The probable source of this exotic component is the areas of high-surficial radioactivity observed by orbital gamma ray spectrometry, such as those at Fra Mauro and Archimedes. If the exotic component is fine-grained KREEP, the origin and distribution of KREEP fragments in the soils are identified. It is suggested that the exotic component represents trace element enriched material located at some depth in the Imbrium area which was surficially deposited during Imbrium excavation.
Document ID
19750055559
Acquisition Source
Legacy CDMS
Document Type
Conference Proceedings
Authors
Evensen, N. M.
Murthy, V. R.
Coscio, M. R., Jr. (Minnesota, University Minneapolis, Minn., United States)