Major (Fe, Mn, Al) and minor (Cr, Mo, Pb, Zn, Cd) element
analyses of metalliferous sediments in cores from the East Pacific
Rise and Bauer Deep indicate that the Bauer Deep sediments are
similar in chemistry and origin to metalliferous sediments of the
East Pacific Rises.
Fe, Pb, and Zn are strongly associated in both cores and are
probably related to the hydrothermal processes which are postulated
to occur on the East Pacific Rise. Incomplete Cd data suggest that
Cd may also be released during hydrothermal leaching of basalt
Mn may originate by precipitation from hydrothermal solutions or by
normal authigenic precipitation from sea water. The similar
accumulation rates of Mo in both cores, and poor correlation of Mo
with Fe imply that Mo is being extracted from sea water. The low
abundances of Cr and Al in metalliferous sediments suggest that
detritus is a minor component of the sediments.
Poorly crystalline smectites constitute a major mineralogical
phase of metalliferous sediments. Chemical and mineralogical
studies indicate that the smectite is an iron-rich montmorillonite,
similar in composition to the bulk sediment.
Information on sedimentation rates in the two cores indicate
that most elements are accumulating faster on the East Pacific Rise
than in the Bauer Deep. Accumulation rates of metals in the Bauer
Deep have decreased up to the present and are currently similar to
those for normal pelagic sediments. It is inferred that the sedimentation
rates in the Bauer Deep are influenced by the proximity of the
East Pacific Rise, It appears that sediments in the Bauer Deep are
largely the product of hydrothermal processes on the East Pacific
Rise, and that the precipitates are transported in suspension to the
Bauer Deep. Authigenic precipitation of elements from sea water
also occurs, having a stronger influence on the sediments as the
precipitation of rise-crest material decreases away from the ridge. / Graduation date: 1974
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/29284 |
| Date | 02 October 1973 |
| Creators | Kendrick, John William |
| Contributors | Heath, G. Ross |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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