Figure F26. Analyses for all Leg 187 glasses in relation to the 0- to 7-Ma data fields from Figure F25. Values plotted are averages of all shipboard replicates for each individual sample. A. Zr/Ba vs. Ba. Data are color coded according to the field in which they plot. Yellow triangles lie outside the 0- to 7-Ma fields and are referred to as Transitional Pacific (TP) because they appear to extend the Pacific field in the direction of Zone A propagating rift tip (PRT) lava compositions. The red triangle is a glass from Hole 1164A that plots at the boundary between the Pacific and Indian fields. B. Na₂O/TiO₂ vs. MgO. Color coding is defined by the Ba-Zr systematics in A. Note that no Leg 187 sample plots in the 0- to 7-Ma Indian field, but, with the exception of four Pacific samples, there is a clear division between Pacific and Indian samples. These four samples plot to the left of the Segment B5 tie line in A, a region where small analytical errors in Ba result in large shifts in plotting position. Note also that TP samples plot in both fields. Dashed line = approximate geochemical boundary between Indian- and Pacific-type zero-age Southeast Indian Ridge basalt glass.