Observation of manganese nodules and crusts recovered during the CHAIN 115 cruise from Nov 1973 until June 1974 in the Atlantic Ocean ...

• Main Authors: Johnson, David A, Ledbetter, Michael T, Burckle, Lloyd H
• Format: Dataset
• Language: English
• Published: PANGAEA 1977
• Subjects: Event label; Date/Time of event; Latitude of event; Longitude of event; Elevation of event; Method/Device of event; Sample ID; DEPTH, sediment/rock; Depth, top/min; Depth, bottom/max; Position; Deposit type; Quantity of deposit; Size; Substrate type; Sediment type; Comment; Description; Uniform resource locator/link to image; Piston corer; Trigger corer; Dredge; Gravity corer; Chain115; Chain; NOAA and MMS Marine Minerals Geochemical Database NOAA-MMS; Antarc*; Antarctic
• Online Access: https://dx.doi.org/10.1594/pangaea.857913; https://doi.pangaea.de/10.1594/PANGAEA.857913

Investigations of piston cores from the Vema Channel and lower flanks of the Rio Grande Rise suggest the presence of episodic flow of deep and bottom water during the Late Pleistocene. Cores from below the present-day foraminiferal lysocline (at ~4000 m) contain an incomplete depositional record consisting of Mn nodules and encrustations, hemipelagic clay, displaced high-latitude diatoms, and poorly preserved heterogeneous microfossil assemblages. Cores from the depth range between 2900 m and 4000 m contain an essentially complete Late Pleistocene record, and consist of well-defined carbonate dissolution cycles with periodicities of ~100,000 years. Low carbonate content and increased dissolution correspond to glacial episodes, as interpreted by oxygen isotopic analysis of bulk foraminiferal assemblages. The absence of diagnostic high-latitude indicators (Antarctic diatoms) within the dissolution cyclss, however, suggests that AABW may not have extended to significantly shallower elevations on the lower ... : The CHAIN 115 dredges are described in: hdl:10013/epic.46769.d011.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1989 NOAA-NCEI compiled the NOAA-MMS Marine Minerals Geochemical Database from journal articles, technical reports and unpublished sources from other institutions.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. ...