@article{fdi:010054195,
  title = {{J}uvenile paleoproterozoic crust evolution during the {E}burnean orogeny (similar to 2.2-2.0 {G}a), western {B}urkina {F}aso},
  author = {{B}aratoux, {L}enka and {M}etelka, {V}. and {N}aba, {S}. and {J}essell, {M}ark and {G}regoire, {M}. and {G}anne, {J}{\'e}r{\^o}me},
  editor = {},
  language = {{ENG}},
  abstract = {{W}e have investigated three greenstone belts ({B}oromo, {H}ounde, and {B}anfora) and associated granitoid terrains, which form part of the {E}burnean orogen, situated in western {B}urkina {F}aso. {T}hese belts expose tholeiitic basalts (basal unit) followed by calc-alkaline intermediate predominantly effusive volcanic and sedimentary suites geochemically reminiscent of present-day volcanic island arc environments. {T}he basal mafic unit probably corresponds to a juvenile arc crust or oceanic plateau. {I}t contains unusual megacrystic tholeiitic basalts, allowing us to correlate the western margin of the {B}oromo belt with the eastern margin of the {H}ounde belt. {T}hese two {N}-{S} trending belt-parallel tholeiitic units are interpreted as limbs of a crustal scale anticline, intruded and partially obliterated by tonalite-trondhjemite-granodiorite ({TTG}) and granite intrusions. {T}hree deformation events ({D}1-{D}3) can be distinguished in western {B}urkina {F}aso. {T}he first deformation phase ({D}1) operated under an {E}-{W} to {WNW}-oriented compression. {R}egional greenschist to lower amphibolite facies metamorphism and intense folding characterize early-{E}burnean deformation phases, during which time the crust was thickened by lateral shortening of volcanic island arcs and concomitant magma input. {T}he crustal-scale antiform between the {B}oromo and {H}ounde belts is attributed to the {D}1 event. {S}hallow water detrital {T}arkwaian-type sediments were deposited during the late {D}1 event within the {H}ounde belt, in a belt-parallel basin extending for 400 km. {T}he subsequent {D}2 phase overprints the structural grain of the study area, and is best visible in airborne magnetic data. {I}t is characterized by {N} to {NE}-trending transcurrent shear zones, which are considered preferred host structures for gold mineralization. {W}e suggest that the newly formed and thickened crust reached the maximum thickness supportable by a weak and hot mantle during the {D}1 phase, and the pure shear dominated compressional regime switched to simple shear dominated transgression during the subsequent {D}2 phase. {G}ranitoid diapirism played an important role at all stages of the {E}burnean crustal growth processes in particular through early volume addition to the newly formed orogen and through later accommodating part of the lateral shortening. {P}luton emplacement contributed to the greenstone belt structuration at local scales; however, the regional scale system geometry was controlled by coaxial shortening of the viscous volcanic units (basalts, gabbros, and andesites) of the greenstone belts, supported by coeval magma input. {T}he last {D}3 deformation, which is either late-{E}burnean or perhaps even {P}an-{A}frican in age, is characterized by shallow {N} or {S} dipping minor thrust faults or an {E}-{W} trending steeply dipping spaced crenulation cleavage and kink folds, occurring mainly in highly anisotropic lithologies across the study region.},
  keywords = {{W}est {A}frica ; {B}urkina {F}aso ; {P}aleoproterozoic ; {S}tructural analysis ; {M}agmatic and tectonic accretion ; {G}eodynamic model},
  booktitle = {},
  journal = {{P}recambrian {R}esearch},
  volume = {191},
  numero = {1-2},
  pages = {18--45},
  ISSN = {0301-9268},
  year = {2011},
  DOI = {10.1016/j.precamres.2011.08.010},
  URL = {https://www.documentation.ird.fr/hor/fdi:010054195},
}