Not logged in
PANGAEA.
Data Publisher for Earth & Environmental Science

Borella, Peter E; Adelseck, C (1980): Analysis of Mn-nodules from Leg 51 [dataset publication series]. PANGAEA, https://doi.org/10.1594/PANGAEA.872489, Supplement to: Borella, PE; Adelseck, C (1980): Manganese Micronodules in Sediments: A Subsurface In-Situ Origin, Leg 51, Deep Sea Drilling Project. In: Donnelly, T.; Francheteau, J.; Bryan, W.; Robinson, P.; Flower, M.; Salisbury, M.; et al., Initial Reports of the Deep Sea Drilling Project, U.S. Government Printing Office, LI, LII, LIII, 771-787, https://doi.org/10.2973/dsdp.proc.515253.113.1980

Always quote citation above when using data! You can download the citation in several formats below.

RIS CitationBibTeX CitationShow MapGoogle Earth

Abstract:
Rhodochrosite crystals and manganese oxide micronodules which have formed in situ are found in abundance at depth (76.5 to 106.5 m) in Hole 417A. A gradual transformation of the rhodochrosite to manganese oxide micronodules is observed in many grains throughout the interval. The transformation process initially attacks the edge of the rhodochrosite crystal and proceeds inward, first forming a pseudomorph of the crystal. Some grains exhibit varying degrees of departure from the crystal shape of a true pseudomorph, suggesting either an overgrowth of manganese oxide or late-stage destruction of the pseudomorph. No significant differences were observed in the relative per cent of minor and trace metals when comparing the pure rhodochrosite with the manganese oxide pseudomorphs. This suggests that the manganese and other trace elements were not transported into the system but were incorporated directly from the rhodochrosite as the manganese oxide formed. Grains which did not exhibit pseudomorphic form showed enrichment in some trace elements. We postulate that the diagenetic environment changed from reducing to oxidizing. How and when this change occurred in the sedimentary column remains an enigma.
Source:
Grant, John Bruce; Moore, Carla J; Alameddin, George; Chen, Kuiying; Barton, Mark (1992): The NOAA and MMS Marine Minerals Geochemical Database. National Geophysical Data Center, NOAA, https://doi.org/10.7289/V52Z13FT
Further details:
Warnken, Robin R; Virden, William T; Moore, Carla J (1992): The NOAA and MMS Marine Minerals Bibliography. National Geophysical Data Center, NOAA, https://doi.org/10.7289/V53X84KN
Coverage:
Latitude: 25.110500 * Longitude: -68.041300
Date/Time Start: 1976-12-02T00:00:00 * Date/Time End: 1976-12-02T00:00:00
Event(s):
51-417A * Latitude: 25.110500 * Longitude: -68.041300 * Date/Time: 1976-12-02T00:00:00 * Elevation: -5468.0 m * Penetration: 417 m * Recovery: 250.4 m * Location: North Atlantic/CONT RISE * Campaign: Leg51 * Basis: Glomar Challenger * Method/Device: Drilling/drill rig (DRILL) * Comment: 43 cores; 389.1 m cored; 27.8 m drilled; 64.4 % recovery
Comment:
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.
Size:
2 datasets

Download Data

Download ZIP file containing all datasets as tab-delimited text — use the following character encoding: