CONCLUSIONS

New major and trace element results from ODP Hole 735B reflect the magmatic trends seen in the larger overall sampling conducted shipboard. Multiple magmatic mega-units a few hundred meters across show consistent magmatic trends and are crosscut by primitive microgabbros as well as highly evolved oxide-rich and silicic units. The "crystallization wall" at 180 ppm Ni suggests that primitive gabbros could not be wetted by the highly evolved liquids. Either they were too completely crystallized (retaining no residual melt porosity) or when in a crystalline state they were too mechanically competent to become conduits for melt migration (fracture porosity). The distinct fingerprint of several high-V samples is the first direct geochemical evidence of multiple magmas with multiple liquid lines of descent and reconfirms a major interpretation of the geochemical results to date.

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