| Title | The stability of metal profiles in freshwater and marine sediments |
| Author | Outridge, P M; Wang, F |
| Source | Environmental contaminants: Using natural archives to track sources and long-term trends of pollution; by Blais, J M (ed.); Rosen, M R (ed.); Smol, J P (ed.); . |
| Alt Series | Earth Sciences Sector, Contribution Series 20130196 |
| Publisher | Springer |
| Document | book |
| Lang. | English |
| Media | paper |
| Subjects | environmental geology; geochemistry; marine geology; metallic minerals; sedimentology; sedimentation; sediments; metals; bioturbation; oxidation; oxidation reactions; groundwater pollution; pollution;
pollutants; heavy metals geochemistry; heavy metals contamination; diagenesis; mercury; lead; arsenic; cadmium; copper; molybdenum; nickel; uranium; zinc; sea water geochemistry; water geochemistry; water quality; rhenium |
| Illustrations | geochemical plots; schematic diagrams; equations |
| |
| Program | environmental impacts and adaptation in the northern environment, Environmental Geoscience |
| Abstract | Stability of metal profiles, or the ability to reconstruct the original profiles following their diagenetic redistribution, is a key requirement for robust interpretations of metals in sediments.
Diagenesis is a common problem in the study of metals in freshwater and marine sediments, but its effects are difficult to generalize because they are metal- and site-specific. There are two basic types of diagenesis; both may strongly influenced by
biological activities in sediments: physical, which involves the mixing of surface sediments by bioturbation or wind and wave action, and which may affect all metals in upper sediment layers; and geochemical, which involves chemical reactions between
certain metals in solid-phases and in porewater, and the transport in porewater of dissolved metals. A few metals of environmental or paleo-limnological interest, such as Hg and to a lesser extent Pb, are thought to be geochemically stable in most
settings. Others such as As, Cd, Cu, Mo, Ni, Re, U and Zn are known to be relatively sensitive to oxic-anoxic (redox) changes down-core and over time. This literature review fulfills several aims: describe the patterns and mechanisms of the two main
categories of diagenesis, physical and geochemical; describe three tests of metal profile stability; review environmental and geochemical factors that influence the occurrence and severity of diagenesis, some of which differ significantly between the
two types of diagenesis; present case studies that illustrate working approaches for correcting diagenetically-altered profiles so that part or all of the original history of accumulation can be reconstructed; and finally, present practical
recommendations concerning study site selection, and approaches to detecting diagenesis, which may assist in minimizing or at least identifying the severity of metal redistribution. |
| Summary | (Plain Language Summary, not published)
Diagenesis is a common problem in the study of metals in freshwater and marine sediments, but its effects are difficult to generalize because they are
metal- and site-specific. A few metals of environmental or paleo-limnological interest, such as Hg and to a lesser extent Pb, are thought to be geochemically stable in most settings. Others such as As, Cd, Cu, Mo, Ni, Re, U and Zn are known to be
relatively sensitive to oxic-anoxic (redox) changes down-core and over time. This literature review fulfills several aims: describe the patterns and mechanisms of the two main categories of diagenesis; describe three tests of metal profile stability;
review environmental and geochemical factors that influence the occurrence and severity of diagenesis; present case studies that illustrate working approaches for correcting diagenetically-altered profiles so that part or all of the original history
of accumulation can be reconstructed; and finally, present practical recommendations concerning study site selection, and approaches to detecting diagenesis. |
| GEOSCAN ID | 292932 |
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