@article{fdi:010091982,
  title = {{F}rom paleolake to peatland : paleo environmental changes over glacial and interglacial cycles ({M}id-{P}leistocene) in the {C}olonia {B}asin, {B}razil},
  author = {{M}arquardt, {G}. {C}. and {B}icudo, {D}. {C}. and {Z}anon, {J}. {E}. and {B}icudo, {C}. {E}. {M}. and {H}orák-{T}erra, {I}. and {L}edru, {M}arie-{P}ierre},
  editor = {},
  language = {{ENG}},
  abstract = {{D}iatom and geochemical elements were used to analyze the transition from lake to peatland in the {C}olonia basin, {S}ao {P}aulo, {B}razil; local versus regional driving factors were examined. {S}ediment core {COL}17-1, section 1470-800 cm depth shows five distinct diatom intervals offering insights into environmental changes and ecological characteristics based on sediment sources, diatom productivity, and bog wetness. {C}olonia basin evolution exhibited a progressive transition from mineral elements, associated with catchment instability during the lake stage, to higher levels of organic-rich sediments towards the uppermost section of the core. {T}his shift was accompanied by the increasing presence of elements reflecting redox/productivity dynamics under changing conditions. {S}imultaneously, {B}r concentrations increased during peat formation indicating alterations in organic matter were influenced by atmospheric circulation and precipitation. {D}uring the transition from lake to peatland, the paleolake shallowing process showed successive colonization by benthic acidophilus diatom taxa, indicating a broader littoral zone and subsequent disappearance of diatoms under dry conditions. {A}fter a benthic stage, the diatom content shifted to one of planktonic dominance characterized by {A}ulacoseira sp., marking the return to cold-wet conditions and a moderately deep, flooded environment. {S}ubsequently, the basin evolved into a completely flooded, turbulent peatland dominated by the {A}ulacoseira granulata complex. {A}n uppermost layer sterile in diatom was associated with warmer and drier conditions and decrease in the concentration of mineral elements. {P}resent results compared with core {CO}14 and {L}ake {T}iticaca showed benthic-rich levels during the penultimate glacial period and low benthic abundances. {T}his differed the glacial-interglacial transition from those of {COL}17-1, which was dominated by planktonic-rich levels, suggesting the need for either a reassessment of our age model or the influence of local factors on diatom content. {T}hese findings highlight the sensitivity of diatoms to climate shifts, particularly in tropical regions, across different glacial-interglacial cycles.},
  keywords = {{D}iatoms ; {P}aleoclimate ; {S}ediment cores ; {S}outhern hemisphere ; {T}race elements ; {T}ropics ; {BRESIL}},
  booktitle = {},
  journal = {{P}alaeogeography {P}alaeoclimatology {P}alaeoecology},
  volume = {655},
  numero = {},
  pages = {112528 [11 p.]},
  ISSN = {0031-0182},
  year = {2024},
  DOI = {10.1016/j.palaeo.2024.112528},
  URL = {https://www.documentation.ird.fr/hor/fdi:010091982},
}