@article{fdi:010075171,
  title = {{D}iatom-oxygen isotope record from high-altitude {L}ake {P}etit (2200 m a.s.l.) in the {M}editerranean {A}lps : shedding light on a climatic pulse at 4.2 ka},
  author = {{C}artier, {R}. and {S}ylvestre, {F}lorence and {P}ailles, {C}. and {S}onzogni, {C}. and {C}ouapel, {M}artine and {A}lexandre, {A}. and {M}azur, {J}. {C}. and {B}risset, {E}. and {M}iramont, {C}. and {G}uiter, {F}.},
  editor = {},
  language = {{ENG}},
  abstract = {{I}n the {M}editerranean area, the 4.2 ka {BP} event is recorded with contrasting expressions between regions. {I}n the southern {A}lps, the high-altitude {L}ake {P}etit ({M}ercantour {M}assif, {F}rance; 2200 a.s.l.) offers pollen and diatom-rich sediments covering the last 4800 years. {A} multi-proxy analysis recently revealed a detrital pulse around 4200 cal {BP} due to increasing erosion in the lake catchment. {T}he involvement of a rapid climate change leading to increasing runoff and soil erosion was proposed. {H}ere, in order to clarify this hypothesis, we measured the oxygen isotope composition of diatom silica frustules (delta {O}-18(diatom)) from the same sedimentary core. {D}iatoms were analysed by laser fluorination isotope ratio mass spectrometry after an inert gas flow dehydration. {W}e additionally enhanced the accuracy of the age-depth model using the {B}acon {R} package. {T}he delta {O}-18(diatom) record allows us to identify a 500-year time lapse, from 4400 to 3900 cal {BP}, where delta {O}-18(diatom) reached its highest values (> 31 parts per thousand). delta {O}-18(diatom) was about 3 parts per thousand higher than the modern values and the shifts at 4400 and 3900 cal {BP} were of similar amplitude as the seasonal delta {O}-18(diatom) shifts occurring today. {T}his period of high delta {O}-18(diatom) values can be explained by the intensification of {O}-18-enriched {M}editerranean precipitation events feeding the lake during the ice-free season. {T}his agrees with other records from the southern {A}lps suggesting runoff intensification around 4200 cal {BP}. {P}ossible changes in other climatic parameters may have played a concomitant role, including a decrease in the contribution of {O}-18-depleted {A}tlantic winter precipitation to the lake water due to snow deficit. {D}ata recording the 4.2 ka {BP} event in the northwestern {M}editerranean area are still sparse. {I}n the {L}ake {P}etit watershed, the 4.2 ka {BP} event translated into a change in precipitation regime from 4400 to 3900 cal {BP}. {T}his record contributes to the recent efforts to characterize and investigate the geographical extent of the 4.2 ka {BP} event in the {M}editerranean area.},
  keywords = {{FRANCE} ; {ALPES} ; {ZONE} {MEDITERRANEENNE}},
  booktitle = {},
  journal = {{C}limate of the {P}ast},
  volume = {15},
  numero = {1},
  pages = {253--263},
  ISSN = {1814-9324},
  year = {2019},
  DOI = {10.5194/cp-15-253-2019},
  URL = {https://www.documentation.ird.fr/hor/fdi:010075171},
}