Abstract
One of the basic questions when studying cores for historical reconstructions of environmental changes is whether the profiles of {sup 210}Pb heavy metals and temporal distributions represent actual or have been affected by diagenetic processes. The term refers to processes occurring in the sediment during and after its formation. Such processes can be physical (such as water loss by compaction in clay sludge), biogeochemical (as the decomposition of organic matter) or biological (eg the ingestion of sediments by infauna.) In this chapter we will refer specifically to diagenetic processes caused by the establishment of a vertical zonation of redox conditions and their effects on concentrations of Fe, Mn and other redox-sensitive metals associated. The redox conditions (defined redox potential Eh) of sediments are primarily controlled by the bacterial decomposition of sedimentary organic matter, and are limited by the rate of supply of organic matter (primary production or other sources) and the rate at that accumulates (rate of accumulation of organic matter). During the bacterial decomposition occurs a sequence of reactions involving a succession of oxidants (or electron acceptors) between which the primary oxidant is O{sub 2}. However, when the dissolved O{sub 2} is consumed and the redox potential has decreased
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Ruiz-Fernandez, Ana Carolina;
[1]
Sanchez-Cabeza, Joan-Albert
[2]
- Universidad Nacional Autonoma de Mexico, Instituto de Ciencias del Mar y Limnologia (Mexico)
- Organismo Internacional de la Energia Atomica, Laboratorios del Medio Marino (Monaco)
Citation Formats
Ruiz-Fernandez, Ana Carolina, and Sanchez-Cabeza, Joan-Albert.
Diagenesis and {sup 210}Pb; Diagenesis y {sup 210}Pb.
IAEA: N. p.,
2012.
Web.
Ruiz-Fernandez, Ana Carolina, & Sanchez-Cabeza, Joan-Albert.
Diagenesis and {sup 210}Pb; Diagenesis y {sup 210}Pb.
IAEA.
Ruiz-Fernandez, Ana Carolina, and Sanchez-Cabeza, Joan-Albert.
2012.
"Diagenesis and {sup 210}Pb; Diagenesis y {sup 210}Pb."
IAEA.
@misc{etde_22030295,
title = {Diagenesis and {sup 210}Pb; Diagenesis y {sup 210}Pb}
author = {Ruiz-Fernandez, Ana Carolina, and Sanchez-Cabeza, Joan-Albert}
abstractNote = {One of the basic questions when studying cores for historical reconstructions of environmental changes is whether the profiles of {sup 210}Pb heavy metals and temporal distributions represent actual or have been affected by diagenetic processes. The term refers to processes occurring in the sediment during and after its formation. Such processes can be physical (such as water loss by compaction in clay sludge), biogeochemical (as the decomposition of organic matter) or biological (eg the ingestion of sediments by infauna.) In this chapter we will refer specifically to diagenetic processes caused by the establishment of a vertical zonation of redox conditions and their effects on concentrations of Fe, Mn and other redox-sensitive metals associated. The redox conditions (defined redox potential Eh) of sediments are primarily controlled by the bacterial decomposition of sedimentary organic matter, and are limited by the rate of supply of organic matter (primary production or other sources) and the rate at that accumulates (rate of accumulation of organic matter). During the bacterial decomposition occurs a sequence of reactions involving a succession of oxidants (or electron acceptors) between which the primary oxidant is O{sub 2}. However, when the dissolved O{sub 2} is consumed and the redox potential has decreased enough to favor the most efficient oxidizing the organic matter decomposition can continue through secondary sources of oxidants (suboxic diagenesis). [Spanish] Una de las preguntas basicas cuando estudiamos cores para realizar reconstrucciones historicas de cambios ambientales es si los perfiles de {sup 210}Pb y metales pesados representan las distribuciones temporales reales o si han sido afectados por procesos diageneticos. El termino diagenesis sedimentaria se refiere a los procesos que ocurren en el sedimento durante y despues de su formacion. Estos procesos pueden ser fisicos (como la perdida de agua en lodos arcillosos por compactacion), biogeoquimicos (como la descomposicion de la materia organica) o biologica (por ejemplo, la ingestion de sedimentos por la infauna). En este capitulo nos referiremos especificamente a los procesos diageneticos provocados por el establecimiento de una zonacion vertical de condiciones redox y sus efectos sobre las concentraciones de Fe, Mn y otros metales redox-sensibles asociados. Las condiciones redox (definidas por el potencial redox Eh) de los sedimentos estan controladas principalmente por la descomposicion bacteriana de la materia organica sedimentaria, y estan limitadas por la tasa de suministro de la materia organica (produccion primaria u otras fuentes) y la tasa a la que esta se acumula (tasa de acumulacion de materia organica). Durante la descomposicion bacteriana se produce una secuencia de reacciones que involucra una serie sucesiva de oxidantes (o aceptores de electrones) entre los cuales el O{sub 2} es el oxidante primario. Sin embargo, cuando el O{sub 2} disuelto se ha consumido y el potencial redox ha disminuido lo suficiente para favorecer al oxidante mas eficiente, la descomposicion de la materia organica puede continuar por medio de fuentes de oxidantes secundarias (diagenesis suboxica). Estos oxidantes son utilizados en el orden siguiente.}
place = {IAEA}
year = {2012}
month = {Jul}
}
title = {Diagenesis and {sup 210}Pb; Diagenesis y {sup 210}Pb}
author = {Ruiz-Fernandez, Ana Carolina, and Sanchez-Cabeza, Joan-Albert}
abstractNote = {One of the basic questions when studying cores for historical reconstructions of environmental changes is whether the profiles of {sup 210}Pb heavy metals and temporal distributions represent actual or have been affected by diagenetic processes. The term refers to processes occurring in the sediment during and after its formation. Such processes can be physical (such as water loss by compaction in clay sludge), biogeochemical (as the decomposition of organic matter) or biological (eg the ingestion of sediments by infauna.) In this chapter we will refer specifically to diagenetic processes caused by the establishment of a vertical zonation of redox conditions and their effects on concentrations of Fe, Mn and other redox-sensitive metals associated. The redox conditions (defined redox potential Eh) of sediments are primarily controlled by the bacterial decomposition of sedimentary organic matter, and are limited by the rate of supply of organic matter (primary production or other sources) and the rate at that accumulates (rate of accumulation of organic matter). During the bacterial decomposition occurs a sequence of reactions involving a succession of oxidants (or electron acceptors) between which the primary oxidant is O{sub 2}. However, when the dissolved O{sub 2} is consumed and the redox potential has decreased enough to favor the most efficient oxidizing the organic matter decomposition can continue through secondary sources of oxidants (suboxic diagenesis). [Spanish] Una de las preguntas basicas cuando estudiamos cores para realizar reconstrucciones historicas de cambios ambientales es si los perfiles de {sup 210}Pb y metales pesados representan las distribuciones temporales reales o si han sido afectados por procesos diageneticos. El termino diagenesis sedimentaria se refiere a los procesos que ocurren en el sedimento durante y despues de su formacion. Estos procesos pueden ser fisicos (como la perdida de agua en lodos arcillosos por compactacion), biogeoquimicos (como la descomposicion de la materia organica) o biologica (por ejemplo, la ingestion de sedimentos por la infauna). En este capitulo nos referiremos especificamente a los procesos diageneticos provocados por el establecimiento de una zonacion vertical de condiciones redox y sus efectos sobre las concentraciones de Fe, Mn y otros metales redox-sensibles asociados. Las condiciones redox (definidas por el potencial redox Eh) de los sedimentos estan controladas principalmente por la descomposicion bacteriana de la materia organica sedimentaria, y estan limitadas por la tasa de suministro de la materia organica (produccion primaria u otras fuentes) y la tasa a la que esta se acumula (tasa de acumulacion de materia organica). Durante la descomposicion bacteriana se produce una secuencia de reacciones que involucra una serie sucesiva de oxidantes (o aceptores de electrones) entre los cuales el O{sub 2} es el oxidante primario. Sin embargo, cuando el O{sub 2} disuelto se ha consumido y el potencial redox ha disminuido lo suficiente para favorecer al oxidante mas eficiente, la descomposicion de la materia organica puede continuar por medio de fuentes de oxidantes secundarias (diagenesis suboxica). Estos oxidantes son utilizados en el orden siguiente.}
place = {IAEA}
year = {2012}
month = {Jul}
}