Figure F55. Total alkalies vs. silica diagram (after Le Bas et al., 1986) illustrating the tholeiitic and (apparently) alkalic compositions of samples of fine-grained lithic and vitric tuff from Site 1184. The high-alkali samples are from above Core 192-1184A-39R, whereas the low-alkali samples are from below this interval, where unaltered glass is generally present. The dashed line separates Hawaiian tholeiitic and alkalic lavas (Macdonald and Katsura, 1964).

Figure F55. Total alkalies vs. silica diagram (after Le Bas et al., 1986) illustrating the tholeiitic and (apparently) alkalic compositions of samples of fine-grained lithic and vitric tuff from Site 1184. The high-alkali samples are from above Core 192-1184A-39R, whereas the low-alkali samples are from below this interval, where unaltered glass is generally present. The dashed line separates Hawaiian tholeiitic and alkalic lavas (Macdonald and Katsura, 1964).