68815 contains a variety of small (~1 mm) anorthositic clasts welded in a heterogeneous, glassy groundmass. The brown to yellow basaltic glasses are banded on a fine scale in complex swirl and lobate patterns. The unmelted fragments include gabbroic, noritic and troctolitic variants, but all are rich in plagioclase feldspar. Our thin section contains dark basaltic glass and a large light-coloured clast containing small, anhedral orthopyroxene and olivine grains dispersed throughout a feldspar groundmass.
The sample weighed 1789 grams before analysis. Glass and clasts have been dated at 3.811 to 4.073 billion years (Ar/Ar).
Further details of this and other Apollo samples are here: http://curator.jsc.nasa.gov/lunar/
The Apollo 16 landing site was in the hilly region around Descartes crater in the lunar highlands. The landing spot was chosen to allow the astronauts to gather geologically older lunar material (Descartes Formation and the Cayley Formation) than the samples obtained in the first four landings, which were in or near lunar maria.
The mission lasted 11.1 days, with a stay on the lunar surface of 71 hours. The crew were on the lunar surface for 20.2 hours during which they traversed approximately 27 kilometers and collected approximately 96 kilograms of samples.
Apollo 16 was launched on 16 April 1972.