Figure F4. Total alkalies vs. silica diagram (after Le Bas, 1986) for basement rocks recovered at DSDP Site 289 and ODP Sites 803 and 807 on the Ontong Java Plateau. Data are from Stoeser (1975) and Mahoney et al. (1993). The broken line separates Hawaiian alkalic and tholeiitic basalts (Macdonald and Katsura, 1964).