AS16-0976(M)  & AS16-0974(M)

Figure 46

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 Click here for lunar chart showing location

In contrast to figure 45, which is an oblique view looking southward, this is a vertical view arranged for stereoscopic viewing. North is at the top and the crater Descartes (D) is partly visible at the lower edge. The craters North Ray (N) and South Ray (S) are prominent landmarks used during the planning and conduct of the mission. The LM landed between the two. The age of South Ray is discussed in more detail in figure 105. The smooth materials filling most topographically low areas are mapped as the Cayley Formation. Samples of the Cayley excavated from the craters were collected by the astronauts. Most of the samples consisted of feldspar rich breccia. This is consistent with an early interpretation (Eggleton and Marshall, 1962) that the Cayley accumulated as ejecta from large multiringed basins, probably Imbrium (1400 km to the northwest) and Orientale (2800 km to the west). The more rugged material immediately east of the landing site is designated as the Descartes Formation. Originally interpreted as volcanic deposits, it is now thought to consist mostly of breccia, although the samples collected may not be representative of the entire formation. From the evidence presently available, its origin as basin ejecta, possibly from the Nectaris basin 450 km to the east, seems to be the most likely explanation.   -G.G.S.