Geochemistry on Manganese nodules from the Indian Ocean, supplement to: Glasby, Geoffrey P (1970): The geochemistry of manganese nodules and associated pelagic sediments from the Indian Ocean. Ph. D. Dissertation, Imperial College of Science, Technology and Medicine (University of London), London, United Kingdom

DOI

Manganese nodules from a wide range of marine environments have been analysed for a series of elements by optical spectrography, atomic absorption spectrophotometry and mass spectrometry to assess the influence of the environment of deposition on the trace element assemblage of nodules and a more detailed assessment has been made of the trace element geochemistry of nodules from area 4C on the flanks of the Carlsberg Ridge in the Indian Ocean. The mineralogical characteristics of the nodules are described and a detailed petrographic and Mass spectrometry (A.E.I. MS7) analysis of three selected specimens presented. Finally, a method is developed for the oxygen isotope analysis of manganese nodules and the application to the problems of paleoclimatology discussed. To investigate the correlation of trace element geochemistry of nodules with depth as suggested by Cronan (1967) and Barnes (1967), a detailed comparison of the trace element geochemistry of nodules from shallow water and deep sea environments was undertaken. The results show a fundamental difference in the trace element assemblage of nodules from continental margin environments compared with those from deep sea and seamount environments. The marked enrichment of Mn and consequent depletion of Fe and trade elements in nodules from continental margin environments indicates the influence of diagenetic remobilisation of manganese in reducing environments on the trace element assemblage of manganese nodules. Variations in the mineralogical characteristics of nodules are attributed to variations in the redox conditions at the sediment-water interface and a correlation between nodule mineralogy and trace element geochemistry becomes apparent. The application of these concepts to the assessment of the paleoenvironmental characteristics of deposition of sedimentary manganese ore bodies is discussed. On the Carlsberg Ridge, the distribution of manganese crusts away from the belt of maximum seismicity along the axis of the mid-Ocean Ridge argues strongly against the influence of submarine vulcanism on nodule formation. A consideration of the ocean floor spreading rate indicate5that the thickness of the manganese crusts on the flanks of the Carlsberg Ridge is related to the length of time the nodule has been in contact with seawater. This suggests that, although submarine vulcanicity may have contributed to the overall mass balance of the oceans, manganese nodules form by the direct precipitation of trace elements from sea water. A consideration of the trace element distribution in a series of sediment cores from the flanks of the Carlsberg Ridge indicates that sediment diagenesis plays only a minor role in influencing the trace element distribution in nodules from this environment. Finally, a discussion of the thermodynamics of nodule precipitation is given and the need for a more detailed assessment of the kinetics of uptake of trace elements in nodules stressed.

Identifier
DOI https://doi.org/10.1594/PANGAEA.876376
Related Identifier https://www.worldcat.org/title/geochemistry-of-manganese-nodules-and-associated-pelagic-sediments-from-the-indian-ocean/oclc/930651202&referer=brief_results
Related Identifier https://doi.org/10.7289/V52Z13FT
Related Identifier https://doi.org/10.7289/V53X84KN
Metadata Access https://ws.pangaea.de/oai/provider?verb=GetRecord&metadataPrefix=datacite4&identifier=oai:pangaea.de:doi:10.1594/PANGAEA.876376
Provenance
Creator Glasby, Geoffrey P
Publisher PANGAEA - Data Publisher for Earth & Environmental Science
Publication Year 1970
Rights Creative Commons Attribution 3.0 Unported
OpenAccess true
Representation
Language English
Resource Type Supplementary Collection of Datasets
Format application/zip
Size 10 datasets
Discipline Earth System Research
Spatial Coverage (-123.793W, -49.400S, 177.983E, 55.843N); Atlantic Ocean; Indian Ocean; Gulf of Aden; Carlsberg Ridge; Indian Ocean, Carlsberg Ridge; South Pacific Ocean; Graveglia Valley, Liguria, Italy; Jervis Inlet, Canada; Loch Fyne, Scotland; Southwest Pacific Ocean
Temporal Coverage Begin 1878-09-21T00:00:00Z
Temporal Coverage End 1967-08-21T00:00:00Z