The metal oxide fraction of pelagic sediment in the equatorial North Pacific Ocean: A source of metals in ferromanganese nodules

Journal Article · Mon Aug 01 04:00:00 EDT 1988 · Geochimica et Cosmochimica Acta; (USA)

DOI:https://doi.org/10.1016/0016-7037(88)90193-7· OSTI ID:7164132

Piper, D Z ^[1]

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1. Geological Survey, Menlo Park, CA (USA)

Pelagic sediment recovered at DOMES Site A in the equatorial North Pacific (151{degree}W, 9{degree}15{prime}N) consists of a surface homogeneous layer, approximately 10 cm thick, overlying a strongly mottled layer that is lighter in color. The radiolarian composition of both units is Quaternary. In areas where this sediment was only a few centimeters thick, the underlying sediment was early Tertiary. Clay mineralogy and major oxide composition of the two Quaternary sediments are uniform. Their similarity to continental shale suggests that the sediment has a terrigenous source. Distribution of elements in these sediments is closely related to their concentration in associated surface ferromanganese nodules. The nodules are of two distinct types: those from the area where the Quaternary sediment is relatively thick have {delta}-MnO{sub 2} as the dominant manganese mineral. The ratios of Ni:Mn, Cu:Mn, and Fe:Mn in these nodules approximate the corresponding ratios of the soluble fraction of surface sediment. Todorokite is the dominant mineral of nodules recovered from areas where the Quaternary sediment is thin. Relatively high Cu/Mn, Ni/Mn, and low Fe/Mn ratios of these nodules mirror differences between the soluble fraction of surface and subsurface Quaternary sediment. These composition trends of sediment and nodules at DOME Site A reflect a diagenetic origin for the todorokite nodules and a predominantly hydrogenous origin for the {delta}-MnO{sub 2} nodules.

• OSTI ID: 7164132
• Journal Information: Geochimica et Cosmochimica Acta; (USA), Journal Name: Geochimica et Cosmochimica Acta; (USA) Vol. 52:8; ISSN GCACA; ISSN 0016-7037
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580000* -- Geosciences
CENOZOIC ERA
CHEMICAL COMPOSITION
CHEMISTRY
COBALT
COPPER
DEPOSITION
DIAGENESIS
ELEMENTS
GEOCHEMISTRY
GEOLOGIC AGES
GEOLOGY
IRON COMPOUNDS
MANGANESE COMPOUNDS
MANGANESE ORES
METALS
MINERALIZATION
MINERALOGY
NICKEL
ORES
ORIGIN
PACIFIC OCEAN
PETROLOGY
QUATERNARY PERIOD
RARE EARTHS
SEAS
SEDIMENTS
SURFACE WATERS
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS