Coleman, Max L; Fleet, Andy; Donson, Paul (1982): Geochemistry and isotopes at DSDP Site 68-503 [dataset publication series]. PANGAEA, https://doi.org/10.1594/PANGAEA.817113, Supplement to: Coleman, ML et al. (1982): Preliminary studies of manganese-rich carbonate nodules from Leg 68, Site 503, eastern Equatorial Pacific. In: Prell, WL; Gardner, JV; et al. (eds.), Initial Reports of the Deep Sea Drilling Project (U.S. Govt. Printing Office), 68, 481-489, https://doi.org/10.2973/dsdp.proc.68.123.1982
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Abstract:
Nodules occur in the siliceous calcareous ooze and siliceous marl at Site 503 in the eastern equatorial Pacific. They are present below a depth of about 11 meters throughout the green-colored reduced part of the section down to 228 meters, although they are most abundant between 30 and 85 meters. They are cylindrical or barrel-shaped, up to 70 mm long, and usually have an axial channel through them or are hollow. They appear to have formed around and/or within burrows. XRD studies and microprobe analyses show that they are homogeneous and consist of calcian rhododrosite and minor calcite; Mn is present to the extent of about 30%. Isotopic analyses of the carbonate give carbon values which range from -1.2 per mil to -3.8 per mil, and oxygen isotope compositions vary from +4.0 per mil to +6.0 per mil. These values are different from those for marine-derived carbonates as exemplified by the soft sediment filling of a burrow: d13C, -0.26 per mil; d18O, +1.05 per mil. The carbon isotope data indicate that carbonate derived (possibly indirectly) from seawater was mixed with some produced by organic diagenesis to form the nodules. The d18O values suggest that although they formed near the sediment surface, some modification or the introduction of additional diagenetic carbonate occurred during burial.
Further details:
Project(s):
Deep Sea Drilling Project (DSDP)
Coverage:
Median Latitude: 4.058800 * Median Longitude: -95.637750 * South-bound Latitude: 4.050300 * West-bound Longitude: -95.638700 * North-bound Latitude: 4.067300 * East-bound Longitude: -95.636800
Date/Time Start: 1979-09-06T00:00:00 * Date/Time End: 1979-09-06T00:00:00
Event(s):
68-503A * Latitude: 4.067300 * Longitude: -95.636800 * Date/Time: 1979-09-06T00:00:00 * Elevation: -3672.0 m * Penetration: 235 m * Recovery: 138.2 m * Location: North Pacific/FLANK * Campaign: Leg68 * Basis: Glomar Challenger * Method/Device: Drilling/drill rig (DRILL) * Comment: 54 cores; 235 m cored; 0 m drilled; 58.8 % recovery
68-503B * Latitude: 4.050300 * Longitude: -95.638700 * Date/Time: 1979-09-06T00:00:00 * Elevation: -3672.0 m * Penetration: 112.8 m * Recovery: 94.3 m * Location: North Pacific/FLANK * Campaign: Leg68 * Basis: Glomar Challenger * Method/Device: Drilling/drill rig (DRILL) * Comment: 26 cores; 112.8 m cored; 0 m drilled; 83.6 % 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.
License:
Creative Commons Attribution 3.0 Unported (CC-BY-3.0)
Size:
2 datasets
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Datasets listed in this publication series
- Coleman, ML; Fleet, A; Donson, P (1982): (Table 1) Geochemistry at DSDP Site 68-503. https://doi.org/10.1594/PANGAEA.817110
- Coleman, ML; Fleet, A; Donson, P (1982): (Table 2) Isotopes at DSDP Site 68-503. https://doi.org/10.1594/PANGAEA.817112