Leg 68: Introduction, Explanatory Notes, and Conventions

The sixty-eighth cruise of Glomar Challenger was devoted to using the newly developed Hydraulic Piston Corer (HPC) to recover undisturbed, continuous sequences of unlithified sediment. We returned to the vicinities of two rotary-drilled sites (83 and 154). The stratigraphy of these sites indicated that uninterrupted sections of late Neogene and Quaternary sediment should exist at these locations. The ship left Curacao, Dutch Antilles, on 13 August 1979, cored for 11 days at Site 502, and transited from the Caribbean through the Panama Canal. Site 503, in the eastern equatorial Pacific, was cored for seven days, and we then finally transited to Salinas, Ecuador. The results of this cruise (reported in this volume) include preliminary descriptions, based primarily on shipboard observations and analyses, of the material recovered (site chapters) and additional studies performed ashore after the cruise, either by scientists who participated in the cruise or by other invited investigators. The main purpose of this volume is to present not an exhaustive study of the sediment recovered but rather a description, as detailed as possible, of the material recovered on Leg 68 accompanied by interpretations and conclusions that remain preliminary