Figure 8.--Geologic maps of the Sandia Mountains, N.M., to illustrate the process of generalizing data for the Geologic Map of the United States. A, Representation of the area on the primary source, the Geologic Map of New Mexico of 1965; original scale 1:500,000. B, The area when generalized, somewhat revised, and replotted on a scale of 1:1,000,000. C, The area as shown on the Geologic Map of the United States, a further generalization from B; original scale 1:2,500,000. The representation in C appears crude by comparison with A and B, but contains the maximum detail possible for publication scale.