Fig. 6. Weight percentages of major oxides plotted against %SiO₂ for samples nos. 13-16 and 33-44 (black dots), including diorite, transition rocks, and aplite dikes in diorite-gabbro wall rocks in the Kernville pluton. Open circle = sample no. 16 (diorite adjacent to the Isabella pluton). Outlined fields trace position of diorite-gabbro wall rocks (dark-shaded field) and granitic rocks of the Isabella pluton (light-shaded field) shown in Fig. 24 in Collins (1988). Arrows indicate localized loss of K₂O and proportional enrichment in Na₂O; see also Fig. 24 in Collins (1988). The loss of K₂O suggests that some of the K that forms K-feldspar (microcline) in the recrystallized granitic rocks is derived partly from the biotite in the modified diorite wall rock. More K must come in from deeper sources to account for all K-feldspar, and some Si must come in to explain the volumes of quartz.