@article{PAR00025934,
  title = {{C}an {Z}n isotopes in sediments record past eutrophication of freshwater lakes ? {A} pilot study at {L}ake {B}aldegg ({S}witzerland)},
  author = {{J}uillot, {F}arid and {N}oel, {V}. and {L}ouvat, {P}. and {G}elabert, {A}. and {J}ouvin, {D}. and {G}ottlicher, {J}. and {B}elin, {S}. and {M}uller, {B}. and {M}orin, {G}. and {V}oegelin, {A}.},
  editor = {},
  language = {{ENG}},
  abstract = {{I}n this study, the speciation and isotopic composition of {Z}n were traced across the sediments of a freshwater lake that experienced one hundred years of strong eutrophication, in order to assess the potential of sedimentary {Z}n isotopes to record such an environmental disturbance. {T}he results indicate that the sedimentary {Z}n isotope signal varied with the change from pre-eutrophic to eutrophic conditions in the investigated lake. {T}he average delta 66{Z}n{JMC} value of the dominantly allochthonous lithogenic sediments deposited during the pre-eutrophic period was +0.27%o +/- 0.05%o (i.e. similar to the delta 66{Z}n{JMC} value of +0.28%o +/- 0.05%o proposed for {B}ulk {S}ilicate {E}arth), while enhanced autochthonous biochemical sedimentation during the eutrophic period resulted in significantly lower delta 66{Z}n{JMC} values down to +0.04%o +/- 0.06%o. {S}ynchrotron-based {X}-ray absorption spectroscopy data revealed a concomitant change in {Z}n speciation from a dominant fraction of {Z}n in clay minerals during the pre-eutrophic period to a major fraction of {Z}n in {Z}n{S} during the eutrophic period. {A} linear regression relating the sedimen-tary {Z}n isotope signal to the fraction of {Z}n in {Z}n{S} indicated delta 66{Z}n{JMC} values of +0.27%o +/- 0.06%o and 0.00%o +/- 0.08%o for {Z}n in clay minerals and in {Z}n{S}, respectively. {T}he enrichment of light {Z}n in {Z}n{S} in the eutrophic sediments is tentatively attributed to enhanced biological uptake of light {Z}n in the water column, which resulted in an enhanced flux of organic-bound {Z}n towards the sediments and further transformation of organic {Z}n into {Z}n{S} upon biomass mineralization during early diagenesis. {T}his hypothesis is in agreement with the fractionation towards lighter {Z}n reported for both biological uptake of {Z}n and {Z}n{S} precipitation. {T}he results of this study emphasize the potential of sedimentary {Z}n isotopes to register past eutrophic periods in freshwater lakes, and thus to serve as a probe of paleo-environmental conditions and/or past land use at the catchment scale.},
  keywords = {{Z}inc ; {I}sotopes ; {S}peciation ; {S}ediments ; {F}reshwater lake ; {E}utrophication ; {SUISSE}},
  booktitle = {},
  journal = {{C}hemical {G}eology},
  volume = {620},
  numero = {},
  pages = {121321 [12 p.]},
  ISSN = {0009-2541},
  year = {2023},
  DOI = {10.1016/j.chemgeo.2023.121321},
  URL = {https://www.documentation.ird.fr/hor/{PAR}00025934},
}