@article{fdi:010080427,
  title = {{N}eoproterozoic magmatic evolution of the southern {O}uaddai {M}assif ({C}had)},
  author = {{D}jerossem, {F}. and {B}erger, {J}. and {V}anderhaeghe, {O}. and {I}sseini, {M}. and {G}anne, {J}{\'e}r{\^o}me and {Z}eh, {A}.},
  editor = {},
  language = {{ENG}},
  abstract = {{T}his paper presents new petrological, geochemical, isotopic ({N}d) and geochronological data on magmatic rocks from the poorly known southern {O}uaddai massif, located at the southern edge of the so-called {S}aharan metacraton. {T}his area is made of greenschist to amphibolite facies metasediments intruded by large pre- to syn-tectonic batholiths of leucogranites and an association of monzonite, granodiorite and biotite granite forming a late tectonic high-{K} calc-alkaline suite. {U}-{P}b zircon dating yields ages of 635 +/- 3 {M}a and 613 +/- 8 {M}a on a peraluminous biotite-leucogranite (containing numerous inherited {A}rchean and {P}aleoproterozoic zircon cores) and a muscovite-leucogranite, respectively. {G}eochemical fingerprints are very similar to some evolved {H}imalayan leucogranites suggesting their parental magmas were formed after muscovite and biotite dehydration melting of metasedimentary rocks. {A} biotite-granite sample belonging to the late tectonic high-{K} to shoshonitic suite contains zircon rims that yield an age of 540 +/- 5 {M}a with concordant inherited cores crystallized around 1050 {M}a. {G}iven the high-{M}g# (59) andesitic composition of the intermediate pyroxene-monzonite, the very similar trace-element signature between the different rock types and the unradiogenic isotopic signature for {N}d, the late-kinematic high-{K} to shoshonitic rocks formed after melting of the enriched mantle and further differentiation in the crust. {T}hese data indicate that the southern {O}uaddai was part of the {P}an-{A}frican belt. {I}t is proposed that it represents a continental back-arc basin characterized by a high-geothermal gradient during {E}arly {E}diacaran leading to anatexis of middle to lower crustal levels. {A}fter tectonic inversion during the main {P}an-{A}frican phase, late kinematic high-{K} to shoshonitic plutons emplaced during the final post-collisional stage.},
  keywords = {{C}entral {A}frica {O}rogenic {B}elt ; {P}an-{A}frican ; {S}aharan {M}etacraton ; peraluminous granites ; shoshonitic magmatism ; {TCHAD} ; {SAHARA} ; {OUADDAI} {MASSIF}},
  booktitle = {},
  journal = {{BSGF}-{E}arth {S}ciences {B}ulletin},
  volume = {191},
  numero = {},
  pages = {34 [22 ]},
  ISSN = {0037-9409},
  year = {2020},
  URL = {https://www.documentation.ird.fr/hor/fdi:010080427},
}