@article{fdi:010072995, title = {{P}edo-sedimentary constituents as paleoenvironmental proxies in the {S}udano-{S}ahelian belt during the {L}ate {Q}uaternary (southwestern {C}had {B}asin)}, author = {{D}iaz, {N}. and {D}ietrich, {F}. and {S}ebag, {D}avid and {K}ing, {G}.{E}. and {V}alla, {P}.{G}. and {D}urand, {A}. and {G}arcin, {Y}. and {S}aulieu, {G}eoffroy de and {D}eschamps, {P}ierre and {H}erman, {F}. and {V}errechia, {E}.{P}.}, editor = {}, language = {{ENG}}, abstract = {{C}limate and environmental changes since the {L}ast {G}lacial {M}aximum in the tropical zone of {W}est {A}frica are usually inferred from marine and continental records. {I}n this study, the potential of carbonate pedo-sedimentary geosystems, i.e. {V}ertisol relics, to record paleoenvironmental changes in the southwestern part of {C}had {B}asin are investigated. {A} multi-dating approach was applied on different pedogenic organo-mineral constituents. {O}ptically stimulated luminescence ({OSL}) dating was performed on the soil {K}-rich feldspars and was combined with radiocarbon dating on both the inorganic (14{C}inorg) and organic carbon (14{C}org) soil fractions. {T}hree main pedo-sedimentary processes were assessed over the last 20 ka {BP}: 1) the soil parent material deposition, from 18 ka to 12 ka {BP} ({OSL}), 2) the soil organic matter integration, from 11 cal ka to 8 cal ka {BP} (14{C}org), and 3) the pedogenic carbonate nodule precipitation, from 7 cal ka to 5 cal ka {BP} (14{C}inorg). {T}hese processes correlate well with the {C}had {B}asin stratigraphy and {W}est {A}frican records and are shown to be related to significant changes in the soil water balance responding to the evolution of continental hydrology during the {L}ate {Q}uaternary. {T}he last phase affecting the {V}ertisol relics is the increase of erosion, which is hypothesized to be due to a decrease of the vegetation cover triggered by (i) the onset of drier conditions, possibly strengthened by (ii) anthropogenic pressure. {A}rchaeological data from {F}ar {N}orth {C}ameroon and northern {N}igeria, as well as sedimentation times in {L}ake {T}illa (northeastern {N}igeria), were used to test these relationships. {T}he increase of erosion is suggested to possibly occur between c. 3 cal ka and 1 cal ka {BP}. {F}inally, satellite images revealed similar geosystems all along the {S}udano-{S}ahelian belt, and initial 14{C}inorg ages of the samples collected in four sites gave similar ages to those reported in this study. {C}onsequently, the carbonate pedo-sedimentary geosystems are valuable continental paleoenvironmental archives and soil water balance proxies of the semiarid tropics of {W}est {A}frica.}, keywords = {{PALEOENVIRONNEMENT} ; {PALEOCLIMAT} ; {QUATERNAIRE} ; {PEDOGENESE} ; {MOUSSON} ; {VERTISOL} ; {DATATION} ; {CARBONATE} ; {LUMINESCENCE} ; {ISOTOPE} {RADIOACTIF} ; {EAU} {DU} {SOL} ; {CAMEROUN} ; {TCHAD} {LAC} ; {ZONE} {SOUDANOSAHELIENNE} ; {ZONE} {SEMIARIDE}}, booktitle = {}, journal = {{Q}uaternary {S}cience {R}eviews}, volume = {191}, numero = {}, pages = {348--362}, ISSN = {0277-3791}, year = {2018}, DOI = {10.1016/j.quascirev.2018.05.022}, URL = {https://www.documentation.ird.fr/hor/fdi:010072995}, }