Apollo 11 drive-tube core samples: an initial physical analysis of lunar surface sediment

Two drive-tube core samples were obtained at Tranquillity Base. Fines include much glass, are unweathered, medium gray, loose, nonstructured, very weakly coherent, and demonstrate both accumulation and mixing in a waterless vacuum environment. In contrast to chemical weathering characteristic on the earth, lunar alteration processes are primarily mechanical. We infer that environmental processes of the lunar surface may be expressed as follows: R (regolith) = f(cl, p, r, t, b, a, . . .), in which climate (cl) is constant and the time (t)-de-pendent processes of bombardment (b) and accumulation (a) assume significance unparalleled on the earth because of their effects on parent material (p) and relief (r).