@article{fdi:010074325,
  title = {{T}he {L}ake {CHA}d {D}eep {DRILL}ing project ({CHADRILL}) - targeting similar to 10 million years of environmental and climate change in {A}frica},
  author = {{S}ylvestre, {F}lorence and {S}chuster, {M}. and {V}ogel, {H}. and {A}bdheramane, {M}. and {A}riztegui, {D}. and {S}alzmann, {U}. and {S}chwalb, {A}. and {W}aldmann, {N}. and {I}cdp {C}hadrill {C}onsortium},
  editor = {},
  language = {{ENG}},
  abstract = {{A}t present, {L}ake {C}had (similar to 13 degrees'{N}, similar to 14 degrees {E}) is a shallow freshwater lake located in the {S}ahel/{S}ahara region of central northern {A}frica. {T}he lake is primarily fed by the {C}hari-{L}ogone river system draining a similar to 600 000 km(2) watershed in tropical {A}frica. {D}ischarge is strongly controlled by the annual passage of the intertropical convergence zone ({ITCZ}) and monsoon circulation leading to a peak in rainfall during boreal summer. {D}uring recent decades, a large number of studies have been carried out in the {L}ake {C}had {B}asin ({LCB}). {T}hey have mostly focused on a patchwork of exposed lake sediments and outcrops once inhabited by early hominids. {A} dataset generated from a 673m long geotechnical borehole drilled in 1973, along with outcrop and seismic reflection studies, reveal several hundred metres of {M}iocene-{P}leistocene lacustrine deposits. {CHADRILL} aims to recover a sedimentary core spanning the {M}iocene-{P}leistocene sediment succession of {L}ake {C}had through deep drilling. {T}his record will provide significant insights into the modulation of orbitally forced changes in northern {A}frican hydroclimate under different climate boundary conditions such as high {CO}2 and absence of {N}orthern {H}emisphere ice sheets. {T}hese investigations will also help unravel both the age and the origin of the lake and its current desert surrounding. {T}he {LCB} is very rich in early hominid fossils ({A}ustralopithecus bahrelghazali; {S}ahelanthropus tchadensis) of {L}ate {M}iocene age. {T}hus, retrieving a sediment core from this basin will provide the most continuous climatic and environmental record with which to compare hominid migrations across northern {A}frica and has major implications for understanding human evolution. {F}urthermore, due to its dramatic and episodically changing water levels and associated depositional modes, {L}ake {C}had's sediments resemble maybe an analogue for lake systems that were once present on {M}ars. {C}onsequently, the study of the subsurface biosphere contained in these sediments has the potential to shed light on microbial biodiversity present in this type of depositional environment. {W}e propose to drill a total of similar to 1800m of poorly to semi-consolidated lacustrine, fluvial, and eolian sediments down to bedrock at a single on-shore site close to the shoreline of present-day {L}ake {C}had. {W}e propose to locate our drilling operations on-shore close to the site where the geotechnical {B}ol borehole (13 degrees 28'{N}, 14 degrees 44'{E}) was drilled in 1973. {T}his is for two main reasons: (1) nowhere else in the {C}had {B}asin do we have such detailed information about the lithologies to be drilled; and (2) the {B}ol site is close to the depocentre of the {C}had {B}asin and therefore likely to provide the stratigraphically most continuous sequence.},
  keywords = {{TCHAD} ; {NIGER} ; {NIGERIA} ; {CAMEROUN} ; {TCHAD} {LAC} {BASSIN}},
  booktitle = {},
  journal = {{S}cientific {D}rilling},
  volume = {24},
  numero = {},
  pages = {71--78},
  ISSN = {1816-8957},
  year = {2018},
  DOI = {10.5194/sd-24-71-2018},
  URL = {https://www.documentation.ird.fr/hor/fdi:010074325},
}