Glomar Challenger cruises, Leg 4 (Rio de Janeiro to San Cristobal, Panama), shipboard site reports, shore laboratory studies (sedimentary petrology, mineralogy, geochemistry, paleomagnetism, micropaleontology), cruise leg synthesis (structure, sedimentation), appended stratigraphic tables, sample locality list, report of laboratory procedures (for reference to earlier volumes, see this Bibliography Vol. 34, No. 6, 10 E70-17485-87)