The Japan Trench area was identified a favorable place for studying convergent margins during the initial deliberations of the IPOD Active Margins Panel. The Leg 56-57 DSDP drill sampling along the Japan Trench transect has indicated that material tectonically accreted during the present convergent episode is limited to a surprisingly small zone. The limits seem well established by the seaward extent of crust with continental thickness and lithologies and by the age and thickness of a terrigenous slope apron covering the presumed but probably unsampled accreted oceanic material.

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1989 NOAA-NCEI compiled the NOAA-MMS Marine Minerals Geochemical Database from journal articles, technical reports and unpublished sources from other institutions.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: Wories, Henk; Whelan, Jean K; Thompson, Peter R; Sakai, Toyusaburo; Robinson, Paul T; Pisciotto, Kenneth A; Murdmaa, Ivar O; Müller, German; Kurnosov, Victor B; Harper, Howard E; Bruns, T; Adelseck, C; Langseth, Marcus G; Okada, Hakuyu (1980): Initial Reports of the Deep Sea Drilling Project. U. S. Government Printing Office, LVI, 436 pp