Composition and origin of sediments at DSDP Site 54-424

Fuente: PANGAEA
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Auteurs principaux: Dymond, Jack R, Corliss, John B, Cobler, Richard, Muratli, Charlotte Meredith, Chou, Christin, Conard, Roberta
Format: Dataset Open Access
Langue:en
Publié: PANGAEA 1980
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author Dymond, Jack R
Corliss, John B
Cobler, Richard
Muratli, Charlotte Meredith
Chou, Christin
Conard, Roberta
author_facet Dymond, Jack R
Corliss, John B
Cobler, Richard
Muratli, Charlotte Meredith
Chou, Christin
Conard, Roberta
collection Datos científicos de ciencias marinas y ambientales
contents The sediments recovered on Deep Sea Drilling Project Leg 54 appear to be mixtures of the normal pelagic sediments of the area and hydrothermally produced manganese and iron phases. The latter are mineralogically and chemically very similar to phases recovered from surficial sampling of the mounds. The hydrothermal nontronite which is approximately 15 meters thick in the three holes is essentially free of carbonate or detrital contaminants. The basal sediments are similar to the carbonate oozes presently being deposited in the region, but are enriched in Mn and Fe. This enrichment appears to be the result of hydrothermal deposition that took place at or near the spreading center and may not be associated with the mounds formation. Three different hypotheses for the formation of the nontronite layer and the mounds deposits are considered. An initial deposition of a widespread nontronite layer and subsequent diapiric-like movement of the layer into carbonates could account for the observed stratigraphy; however, if this be correct, analogous deposits should be present in other DSDP sites. The second hypothesis - replacement of the normal sediments by nontronite - may be feasible, but the high purity of the nontronite requires dissolution and removal of refractory elements. The third hypothesis, metal deposition in an advancing oxidation gradient, is compatible with submersible observations of the mounds; however, it can account only for the high purity of the nontronite by very rapid deposition of the hydrothermal phases.
format Dataset Open Access
id pangaea_https___doi_org_10_1594_PANGAEA_823496
institution PANGAEA
language en
publishDate 1980
publisher PANGAEA
record_format pangaea
spellingShingle Composition and origin of sediments at DSDP Site 54-424
Dymond, Jack R
Corliss, John B
Cobler, Richard
Muratli, Charlotte Meredith
Chou, Christin
Conard, Roberta
54-424; 54-424A; 54-424B; Deep Sea Drilling Project; DRILL; Drilling/drill rig; DSDP; Glomar Challenger; Leg54; North Pacific/MOUND
The sediments recovered on Deep Sea Drilling Project Leg 54 appear to be mixtures of the normal pelagic sediments of the area and hydrothermally produced manganese and iron phases. The latter are mineralogically and chemically very similar to phases recovered from surficial sampling of the mounds. The hydrothermal nontronite which is approximately 15 meters thick in the three holes is essentially free of carbonate or detrital contaminants. The basal sediments are similar to the carbonate oozes presently being deposited in the region, but are enriched in Mn and Fe. This enrichment appears to be the result of hydrothermal deposition that took place at or near the spreading center and may not be associated with the mounds formation. Three different hypotheses for the formation of the nontronite layer and the mounds deposits are considered. An initial deposition of a widespread nontronite layer and subsequent diapiric-like movement of the layer into carbonates could account for the observed stratigraphy; however, if this be correct, analogous deposits should be present in other DSDP sites. The second hypothesis - replacement of the normal sediments by nontronite - may be feasible, but the high purity of the nontronite requires dissolution and removal of refractory elements. The third hypothesis, metal deposition in an advancing oxidation gradient, is compatible with submersible observations of the mounds; however, it can account only for the high purity of the nontronite by very rapid deposition of the hydrothermal phases.
title Composition and origin of sediments at DSDP Site 54-424
topic 54-424; 54-424A; 54-424B; Deep Sea Drilling Project; DRILL; Drilling/drill rig; DSDP; Glomar Challenger; Leg54; North Pacific/MOUND
url https://doi.org/10.1594/PANGAEA.823496