Analysis of sediments at Domes Site A, Pacific Ocean

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Hauptverfasser: Piper, David Z, Rude, P D, Monteith, S
Format: Dataset Open Access
Sprache:en
Veröffentlicht: PANGAEA 1987
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_version_ 1867170472105345024
author Piper, David Z
Rude, P D
Monteith, S
author_facet Piper, David Z
Rude, P D
Monteith, S
collection Datos científicos de ciencias marinas y ambientales
contents The chemical and mineralogical composition of burrowed sediment, recovered in 66 box cores at latitude 9°25'N and longitude 151°15'W in the equatorial Pacific, demonstrates the important role of infauna in determining the geochemistry of pelagic sediment. Haloed burrows, approximately 3 cm across, were present in many of the cores. Within early Tertiary sediment that was covered by less than 5 cm of surface Quaternary sediment in several cores, the burrows in cross-section consist of three units: (1) a dark yellowish-brown central zone of Quaternary sediment surrounded, by (2) a pale yellowish-orange zone (the halo) of Tertiary sediment, which is surrounded by (3) a metal-oxide precipitate; the enclosing Tertiary sediment is dusky brown. Several elements - Mn, Ni, Cu, Co, Zn, Sb and Ce - have been leached from the light-colored halo, whereas Cr, Cs, Hf, Rb, Sc, Ta, Th, U, the rare earth elements exclusive of Ce, and the major oxides have not been leached. The metal-oxide zone, 1-5 mm thick, contains as much as 16% MnO2, as the mineral todorokite. The composition of the todorokite, exclusive of the admixed Tertiary sediment, resembles the composition of the metal deficit of the halo and also the composition of surface ferromanganese nodules that have been interpreted as having a predominantly diagenetic origin. Thus bioturbation contributes not only to the redistribution of metals within pelagic sediment, but also to the accretion of ferromanganese nodules on the sea floor.
format Dataset Open Access
id pangaea_https___doi_org_10_1594_PANGAEA_881020
institution PANGAEA
language en
publishDate 1987
publisher PANGAEA
record_format pangaea
spellingShingle Analysis of sediments at Domes Site A, Pacific Ocean
Piper, David Z
Rude, P D
Monteith, S
NOAA and MMS Marine Minerals Geochemical Database; NOAA-MMS
The chemical and mineralogical composition of burrowed sediment, recovered in 66 box cores at latitude 9°25'N and longitude 151°15'W in the equatorial Pacific, demonstrates the important role of infauna in determining the geochemistry of pelagic sediment. Haloed burrows, approximately 3 cm across, were present in many of the cores. Within early Tertiary sediment that was covered by less than 5 cm of surface Quaternary sediment in several cores, the burrows in cross-section consist of three units: (1) a dark yellowish-brown central zone of Quaternary sediment surrounded, by (2) a pale yellowish-orange zone (the halo) of Tertiary sediment, which is surrounded by (3) a metal-oxide precipitate; the enclosing Tertiary sediment is dusky brown. Several elements - Mn, Ni, Cu, Co, Zn, Sb and Ce - have been leached from the light-colored halo, whereas Cr, Cs, Hf, Rb, Sc, Ta, Th, U, the rare earth elements exclusive of Ce, and the major oxides have not been leached. The metal-oxide zone, 1-5 mm thick, contains as much as 16% MnO2, as the mineral todorokite. The composition of the todorokite, exclusive of the admixed Tertiary sediment, resembles the composition of the metal deficit of the halo and also the composition of surface ferromanganese nodules that have been interpreted as having a predominantly diagenetic origin. Thus bioturbation contributes not only to the redistribution of metals within pelagic sediment, but also to the accretion of ferromanganese nodules on the sea floor.
title Analysis of sediments at Domes Site A, Pacific Ocean
topic NOAA and MMS Marine Minerals Geochemical Database; NOAA-MMS
url https://doi.org/10.1594/PANGAEA.881020