(Table T1) Geochemical composition of gabbroic rocks from ODP Hole 176-735B

Elemental data for 89 whole-rock samples from Hole 735B, 500-1500 meters below seafloor (Ocean Drilling Program Leg 176), are presented. The samples represent the rock types recovered. The data set is compared to shipboard analyses. The index Na/(Na + Al) is used to monitor magmatic evolution. Oxide-rich rocks are enriched in the albite component and are thus derived from relatively evolved melts. Not all evolved magmas precipitated Fe-Ti oxide. The geochemistry of most rocks is largely controlled by the proportion of cumulus clinopyroxene and plagioclase. The primitive magmas had Zr/Nb < 60, Sr = 0.100 ppm, and Sc = 0.35 ppm. All oxide-rich rocks are found to be mixtures of primitive and evolved mineral parageneses, and this supports the concept that Fe-Ti oxide-rich magmas percolated through olivine gabbros.