Lunar Volcanism: Age of the Glass in the Apollo 17 Orange Soil

Science  29 Jun 1973:
Vol. 180, Issue 4093, pp. 1358-1360
DOI: 10.1126/science.180.4093.1358


The formation age of the glass in the orange soil brought back by the Apollo 17 astronauts from the Taurus-Littrow valley has been measured by the 40Ar-39Ar stepwise heating technique to be 3710 ± 60 x 106 years. The orange glass is thus much older than expected. Four fragments, presumably from the subfloor basalt, were also analyzed and have crystallization ages of 3710 ± 70, 3720 ± 50, 3770 ± 50, and 3790 ± 70 x 106 years. These ages do not provide evidence for recent extensive lunar volcanism. The magmatic activity in the Sea of Serenity and the Sea of Tranquillity occurred very close in time, if not contemporaneously. The volcanic activity in the Sea of Tranquillity and the Sea of Serenity may have been triggered by the impact event forming the Sea of Rains basin.