Continuous sections of uppermost ocean crust produced at the East Pacific Rise, including the pillow-sheeted dike and dike-gabbro transitions, have been exposed by rifting in the Hess Deep were explored and sampled during 11 dives of ALVIN in 1990. Over 200 rock samples recovered in 9 dredge hauls. The preliminary studies will be extended by obtaining a comprehensive suite of major-oxide, trace-element, and mineral data using the new ICP-MS at Scripps Institution of Oceanography.
