Grain size distribution, carbon content and wet bulk density of sediment cores in the equatorial Atlantic and the Norwegian Sea ...

Near-surface sediments from the equatorial east Atlantic and the Norwegian Sea exhibit pronounced shear strength maxima in profiles from the peak Holocene and Pleistocene. These semi-indurated layers start to occur at 8-102 cm below the sediment surface and can be explained neither by the modal comp...

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Bibliographic Details
Main Authors: Kassens, Heidemarie, Sarnthein, Michael
Format: Article in Journal/Newspaper
Language:English
Published: PANGAEA 1989
Subjects:
M65
Online Access:https://dx.doi.org/10.1594/pangaea.696097
https://doi.pangaea.de/10.1594/PANGAEA.696097
Description
Summary:Near-surface sediments from the equatorial east Atlantic and the Norwegian Sea exhibit pronounced shear strength maxima in profiles from the peak Holocene and Pleistocene. These semi-indurated layers start to occur at 8-102 cm below the sediment surface and can be explained neither by the modal composition nor by the effective overburden pressure of the sediments. However, scanning electron microscope and microprobe data exhibit micritic crusts and crystal carpets, which are clearly restricted to (undisturbed) samples from indurated layers and form a manifest explanation for their origin. The minerals precipitated comprise calcite, aragonite, and in samples more proximal to the African continent SiO2 needles, and needles of as yet unidentified K-Mg-Fe-Al silicates, crusts of which dominate the indurated layers in the Norwegian Sea. By their stratigraphic position in deep-sea sediments the carbonate-based shear strength maxima are tentatively ascribed to dissolved adjacent pteropod layers from the early ... : Supplement to: Kassens, Heidemarie; Sarnthein, Michael (1989): A link between paleoceanography, early diagenetic cementation, and shear strength maxima in Late Quaternary deep-sea sediments? Paleoceanography, 4(3), 253-269 ...