Fig. 1. Geologic map of the Tuolumne Intrusive Suite, Sierra Nevada, California (after Bateman and Chappell, 1979). The outer quartz diorite intrusions were emplaced first, and subsequently the equigranular and porphyritic facies of the Half Dome granodiorite were intruded into the partly solidified interior of the pluton. The north-south linear-aligned Cathedral Peak granodiorite was intruded next, followed finally by the Johnson granite porphyry. In this sequence, an overall progression from mafic to felsic compositions occurs. Outline area is shown in Figure 2.