@article{fdi:010087753,
  title = {{T}he {A}frican {H}olocene {H}umid {P}eriod in the {T}ibesti mountains (central {S}ahara, {C}had) : climate reconstruction inferred from fossil diatoms and their oxygen isotope composition},
  author = {{Y}acoub, {A}. {N}. and {S}ylvestre, {F}lorence and {M}oussa, {A}. and {H}oelzmann, {P}. and {A}lexandre, {A}. and {D}inies, {M}. and {C}halie, {F}. and {V}allet-{C}oulomb, {C}. and {P}ailles, {C}. and {D}arius, {F}. and {S}onzogni, {C}. and {C}ouapel, {M}artine and {M}azur, {J}. {C}. and {K}ropelin, {S}.},
  editor = {},
  language = {{ENG}},
  abstract = {{T}he climate of the {A}frican {H}olocene {H}umid {P}eriod ({AHHP}) is reconstructed in the {T}ibesti {V}olcanic {M}assif ({TVM}) in the central {S}ahara from well-preserved diatomaceous deposits in the two crater palaeolakes of {T}rou au {N}atron at {P}ic {T}ousside-;and {E}ra {K}ohor at {E}mi {K}oussi. {T}he two records cover the period from-9500 to 4500 cal yr {BP}. {C}limate and palaeoenvironmental changes during this period were inferred from diatom assemblages, interpretation of variations in their oxygen isotope composition (delta(18){O}diatom), reconstruction of lake water conductivity from diatom-based transfer functions, and estimation of the lake water balance ({E}vaporation/{I}nflow ratio, {E}/{I}). {O}ur findings provide evidence for two distinct lacustrine episodes. {D}uring the early to mid-{H}olocene transition, low delta {O}-18-diatom values, high percentages of planktonic diatoms, low lake water conductivity and a positive water balance ({E}/{I} < 1) suggest wet conditions, which were likely related to the optimum of the {AHHP}. {F}rom the mid-to late {H}olocene transition, an aridification trend is revealed by increasing delta {O}-18-diatom values, high percentages of benthic diatoms and a negative water budget ({E}/{I} > 1), occurring as early as 6500 cal yr {BP} and intensifying after 5300 cal yr {BP}. {M}oreover, our data show on average a decrease in precipitation amounts of-35% between the peak and the end of the {AHHP} in the {T}ibesti region. {T}his timing of the {AHHP} in the mountainous {T}ibesti is consistent with the aridification of the central {S}ahara recorded at lowland sites, which has mainly been related to the southward retreat of the {I}ntertropical {C}onvergence {Z}one ({ITCZ}) and the associated {A}frican monsoonal rainfall belt, following the gradually declining summer insolation that led to the termination of the {AHHP}. {O}ur results prove the existence of {H}olocene lakes in the {TVM} craters that developed contemporaneously with the lakes of the {C}hadian basin and the {L}ibyan {S}ahara. {O}n a broader scale, our data share similar hydroclimatic patterns with studies from the eastern and northern {S}ahara.},
  keywords = {{O}xygen isotopes of diatom silica ; {C}rater palaeolakes ; {L}ake water balance ; {D}iatom-based transfer function ; {H}ydroclimate ; {ITCZ} ; {A}ridification ; {TCHAD} ; {SAHARA}},
  booktitle = {},
  journal = {{Q}uaternary {S}cience {R}eviews},
  volume = {308},
  numero = {},
  pages = {108099 [17 p.]},
  ISSN = {0277-3791},
  year = {2023},
  DOI = {10.1016/j.quascirev.2023.108099},
  URL = {https://www.documentation.ird.fr/hor/fdi:010087753},
}