Figure F257. Incompatible trace element ratios, Zr/Y vs. Ti/Y and V/Y, plotted for Hole 1256D rocks and rocks from the northern East Pacific Rise (EPR; 5°–10°N) and the Costa Rica Rift (Site 504). Larger arrow shows normal variation of ratios during either partial melting or fractional crystallization; smaller arrow shows variability explicable by source heterogeneity. LP = lava pond, SF = basalt sheet flow, MF = basalt massive flow, BD = basaltic dike, G = gabbro, QOD = quartz-oxide diorite, TD = trondhjemite dike, GC = ghost core, N EPR = northern EPR, 504B = Hole 504B near the Costa Rica Rift. See “Geochemistry” in “Expedition 309” for the samples labeled 309 and “Geochemistry” in “Expedition 312” for Expedition 312 analyses. Northern EPR data from C.H. Langmuir (unpubl. data, www.petdb.org, 1999). Site 504 data from Autio et al. (1983), Natland et al. (1983), Emmermann (1985), and Tual et al. (1985).
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