The double drive tube core 64001/2 collected on Stone mountain, station 4, Apollo 16 was expected to contain the best samples of material representative of the Descartes formation. Based on the concentrations of 24 elements in one sample from each of the 68 half-centimeter dissection intervals of the lower section of the core tube (64001, 26.4--60.5 cm depth), no layer of soil enriched in materials thought to be representative Descartes material was found. However, all samples between 26 and 48 cm contain material of mare origin. Concentrations of mare material extending over 2--3 half-centimeter dissection intervals occur near 31, 42, and 47 cm depth. Samples from these three zones contain up to 7%, 12%, and 5%, respectively, mare-derived material. Cr/Sc ratios indicate that each zone is composed of a different type of mare basalt. Based on FeO and Fe¿ concentrations and the surface maturity index Is/FeO measured on samples from all 122 dissection intervals of 64001/2 a layer of material slightly more felsic and less mature than typical core material occurs between 14 and 19 cm. The composition of the remaining core material is nearly constant and generally similar to that of other soils from the south and central part of the landing site. All of the soil in the 64001/2 core is mature with respect to surface exposure except the Fe-poor layer (14--19 cm) and an Fe-rich layer (42--43 cm), which is submature. Major changes in the stratigraphy of the core as observed in either the maturity or geochemical data occur near 12, 20, and 48 cm. The 64001/2 soils are a complex mixture of Cayley, Descartes, and other materials, including mare basalt.