U.S. Geological Survey Open File Report # 91-120 February 5, 1991 16th Cruise of the R/V Akademik Boris Petrov (Leg 1) (October 5 - November 15, 1990) Soviet-U.S. Collaborative Geological and Geophysical Survey of the Mid-Atlantic Ridge between 30°N and 34°N Cruise Report Sergei Silantiev (Chief Scientist) Vernadsky Institute of Geochemistry USSR Academy of Sciences Moscow 117975 USSR Kirn D. Klitgord (Co-Chief Scientist) U.S. Geological Survey Woods Hole MA 02543 USA John F. Casey Department of Geosciences University of Houston Houston TX 77204-5503 USA Susan M. Agar Department of Geological Sciences Northwestern University Evanston IL 60208-2150 USA William B. Bryan Woods Hole Oceanographic Institution Woods Hole MA 02543 USA This report is preliminary and has not been reviewed for conformity with U.S. Geological Survey editorial standards and nomenclature. Use of trade names is for the purposes of identification only and does not constitute endorsement by the U.S. Geological Survey.