title: Potassium-uranium systematics of apollo 11 and apollo 12 samples: implications for lunar material history.
abstract: Apollo 11 and Apollo 12 lunar rock suites differ in their potassium-uranium abundance systematics. This difference indicates that relatively little exchange of regolith material has occurred between Mare Tranquillitatis and Oceanus Procellarum. The two suites appear to have been derived from materials of identical potassium and uranium content. It appears unlikely that bulk lunar material has the ratio of potassium to uranium found in chondrites. However, systematic differences in the potassium-uranium ratio between Apollo samples and crustal rocks of the earth do not preclude a common potassium-uranium ratio for bulk earth and lunar material.
authors.forename: F P
authors.initials: FP
authors.lastname: Fanale
authors.forename: D B
authors.initials: DB
authors.lastname: Nash