Basalts recovered from Sites 595 and 596 on Mesozoic crust in the southwest Pacific range from olivine-bearing tholeiites to ferrobasalts. Despite having undergone extensive low-grade alteration, which has raised K and Rb abundances, the basalts have consistent interelement ratios of Ti, Zr, Hf, rare-earth elements, Y, Th, Ik, and Nb. La/Ta (-18), Lan/Ybn (0.6), Ti/Zr (115), Zr/Nb (20), and Th/Hf (0.08) ratios all fall within the range of N-type mid-ocean-ridge basalt. The basalts from Sites 595 and 596 indicate that the Mesozoic Pacific crust was derived from a mantle source by processes similar to those operating at the present-day East Pacific Rise.
Supplement to: Saunders, Andrew D (1987): Geochemistry of basalts from Mesozoic Pacific Ocean crust: Deep Sea Drilling Project Leg 91. In: Menard, HW; Natland, J; Jordan, TH; Orcutt, JA; et al. (eds.), Initial Reports of the Deep Sea Drilling Project, Washington (U.S. Govt. Printing Office), 91, 483-494, doi:10.2973/dsdp.proc.91.115.1987