Skip to Main Content
Book Chapter

Rare Earth Element Fractionation in Hydrogenetic Fe-Mn Crusts: The Influence of Carbonate Complexation and Phosphatization on SM/YB Ratios

By
E. Heinen De Carlo
E. Heinen De Carlo
Department of Oceanography, School of Ocean and Earth Science and Technology, University of Hawaii, Honolulu, HI 96822-2285
Search for other works by this author on:
X. Y. Wen
X. Y. Wen
Department of Oceanography, School of Ocean and Earth Science and Technology, University of Hawaii, Honolulu, HI 96822-2285
Search for other works by this author on:
J. P. Cowen
J. P. Cowen
Department of Oceanography, School of Ocean and Earth Science and Technology, University of Hawaii, Honolulu, HI 96822-2285
Search for other works by this author on:
Published:
January 01, 2000

Abstract:

Hydrogenetic Fe-Mn crust layers accrete sequentially over millions of years and incorporate many trace elements by particle scavenging processes. By regulating the chemical environment at the aqueous/particle interface, conditions in the oceanic water column can thus influence the composition of Fe-Mn crusts. Because crusts are subject to much less diagenesis and post-depositional reworking than most other sedimentary deposits, they represent condensed stratigraphic sequences that reflect oceanic conditions through geologic time. Unfortunately many past efforts to reconstruct growth histories of crusts suffered from limitations inherent in dating techniques. Recently it has been demonstrated that Fe-Mn o ust laminae can be dated reliably using nannofossil biostratigraphy; and a combined approach using biostratigraphy and other dating methods now provides better chronological control on crust stratigraphy than previously available.

In this paper we present high-resolution (<3 mm) rare earth element (REE) profiles in hydrogenetic Fe-Mn crusts from two Pacific seamounts. We evaluate the concentrations of these trace elements in light of results of laboratory scavenging experiments and attempt to resolve the influence of solid-phase mineralogy and seawater chemistry on the extent of REE fractionation in growth layers of crusts. Because the chemistry of the REE in seawater is dominated by complexation with dissolved carbonate we hypothesize that temporal variations in REE fractionation in Fe-Mn crusts reflect primarily changes in the dissolved carbonate content of seawater. The use of the Sm/Yb ratio is proposed as a convenient measure of REE fractionation in Fe-Mn crusts and variations thereof are examined with respect to changes in oceanic carbonate content during the Cenozoic. Shale- normalized Sm/Yb ratios in nonphosphatized sections of crusts from the Pacific are believed to represent unaltered signals of conditions in the oceans at the time of accumulation and correlate inversely with the CCD throughout the Cenozoic.

You do not currently have access to this article.

Figures & Tables

Contents

SEPM Special Publication

Marine Authigenesis: From Global to Microbial

Craig R. Glenn
Craig R. Glenn
Department of Geology and Geophysics, University of Hawaii
Search for other works by this author on:
Liliane Prévôt-Lucas
Liliane Prévôt-Lucas
Centre de Géochimie de la Surface, Strasbourg
Search for other works by this author on:
Jacques Lucas
Jacques Lucas
Université Louis Pasteur, Institut des Sciences de la Teree, Strasbourg
Search for other works by this author on:
SEPM Society for Sedimentary Geology
Volume
66
ISBN electronic:
9781565761889
Publication date:
January 01, 2000

GeoRef

References

Related

Citing Books via

Close Modal
This Feature Is Available To Subscribers Only

Sign In or Create an Account

Close Modal
Close Modal