Figure F58. A. Diagram of total alkalis vs. silica with Le Maitre et al.'s (1989) classification of volcanic rock types. Heavy dashed line = division of data for tholeiitic and alkalic lavas of Hawaii (Macdonald and Katsura, 1964; Macdonald, 1968). Values are normalized to 100 wt% totals. Data for the highly vesicular, carbonate-rich split of Sample 324-U1349A-11R-5 (Piece 1A, 12–15 cm) are off the graph and thus not shown; nor are data for two carbonate-rich veins from Site U1346 (see "Geochemistry" in the "Site U1346" chapter). Also not shown are data for the melt segregation and altered glass of Site U1347. OJP = Ontong Java Plateau (data of Tejada et al., 1996, 2002; Fitton and Godard, 2004), EPR = East Pacific Rise (data of Sinton et al., 1991; Bach et al., 1994; Mahoney et al., 1994), Nazca-ESC = Nazca Ridge and Easter Seamount Chain (Ray et al., unpubl. data). B. K2O vs. loss on ignition (LOI).
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