Preliminary results of a 14-day cruise of the USC&GS ship Oceanographer to the area near the junction of Juan de Fuca Ridge and the Blanco Fracture Zone are reported. About 10 full days of bathymetry (using a narrow beam transducer), magnetic, and gravity were completed. Fifteen dredges were attempted, 13 were successful. A striking bathymetric symmetry up to 15 miles on each side of the axis was found on five crossings of the Juan de Fuca Ridge. This symmetry extends at least 17 and possibly 30 nautical miles along the Ridge axis. Relief features, ranging from 100 to 20 fathoms, were found to correlate with similar features across the axis. This bathymetric symmetry is more striking than the magnetic symmetry and is an independent line of evidence in support of sea-floor spreading. A small, median perched graben along portions of the Juan de Fuca Ridge axis is floored by a very recent basaltic flows which have unusual surface structures.

From 1983 until 1989 NOAA-NCEI compiled the NOAA-MMS Marine Minerals Geochemical Database from journal articles, technical reports and unpublished sources from other institutions. At the time it was the most extended data compilation on ferromanganese deposits world wide. Initially published in a proprietary format incompatible with present day standards it was jointly decided by AWI and NOAA to transcribe this legacy data into PANGAEA. This transfer is augmented by a careful checking of the original sources when available and the encoding of ancillary information (sample description, method of analysis...) not present in the NOAA-MMS database.

Supplement to: Melson, William G (1968): Preliminary results of a geophysical study of portions of the Juan de Fuca Ridge and Blanco Fracture zone: a study performed aboard the USC & GS ship Oceanographer, October 15-26, 1968. ESSA technical memorandum C & GSTM; U.S. Dept. of Commerce, Environmental Science Services Administration, Coast and Geodetic Survey, Rockville, Md, 6