@article{fdi:010077445,
  title = {{O}nset of the supercontinent cycle : evidence for multiple oceanic arc accretion events in the {P}aleoproterozoic {S}efwi {G}reenstone {B}elt of the {W}est {A}frican {C}raton},
  author = {{M}c{F}arlane, {B}. and {T}hebaud, {N}. and {P}arra-{A}villa, {L}. {A}. and {A}rmit, {R}. and {S}pencer, {C}. and {G}anne, {J}{\'e}r{\^o}me and {A}illeres, {L}. and {B}aratoux, {L}enka and {B}etts, {P}. {G}. and {J}essell, {M}. {W}.},
  editor = {},
  language = {{ENG}},
  abstract = {{G}reenstone belts preserved in the {W}est {A}frican {C}raton (2300-2070 {M}a) provide key information for understanding the petrogenetic processes and geodynamic setting for juvenile crust formation during a nascent {P}aleoproterozoic plate tectonic regime. {N}ew geochemical and isotopic data are presented for the magmatic suites exposed in {S}efwi {G}reenstone {B}elt, {SW} {G}hana. {W}e define five distinct plutonic suites, with extrusive equivalents, including: 1) two generations of high {S}i{O}2, {N}a2{O}-rich tonalite-trondhjemite-granodiorite ({TTG}) granitoids; 2) calc-alkaline, {LILE}-enriched diorites; 3) tholeiitic pyroxenite, gabbro and layered mafic intrusives; 4) high-{K} quartz monzonites; and, 5) incompatible element-rich, two-mica granites and muscovite leucogranites. {T}race element patterns of most magmatic suites display negative {N}b-{T}a, {P} and {T}i anomalies and weakly positive {P}b anomalies, suggesting magma genesis in a subduction setting with minor crustal contamination/assimilation. {C}omplementary zircon {U}-{P}b and {L}u-{H}f data indicate contemporaneous emplacement of diorites (epsilon {H}f-(t) = + 2.5 to + 5.4) and low-{HREE} {TTG}s (epsilon {H}f-(t) = + 4.3 to + 7.6) between ca. 2159 and 2153 {M}a, derived from contrasting sources, namely the partial melting of the metasomatised mantle wedge and high-pressure partial melting of low-{K} mafic sources, respectively. {H}igh-{HREE} {TTGS} are attributed to the shallow, partial melting of mafic material. {T}he emplacement of high-{K} quartz monzonites (epsilon {H}f-(t) = +2.5 to +5.2) at ca. 2135 {M}a reveals mixing of mantle-derived magmas and remelting of existing {TTG}s in the crustal pile. {C}onsistently positive epsilon {H}f-(t) values indicate predominantly radiogenic, though heterogeneous, magma sources during crustal growth, derived from precursory material extracted from the depleted mantle and an older crustal component with a minimum age of 2650 {M}a. {M}agmatogenesis of two-mica granites and leucogranites (ca. 2092 and 2081 {M}a) is interpreted to be the product of crustal anatexis during an oceanic arc-arc collisional event, with a proposed suture parallel to the {NW} margin of the {S}efwi {B}elt. {W}e hypothesise that the formation and accretion of the {W}est {A}frican {C}raton reflects the rapid amalgamation of individual oceanic arc terranes, providing potential insight into the transitional plate tectonic regime that may have characterised the {E}arth between 3000 and 2000 {M}a.},
  keywords = {{P}aleoproterozoic ; {S}ubduction-related accretion-collision ; {J}uvenile ; magmatism ; {Z}ircon {U}-{P}b - {L}u-{H}f isotopes ; {W}est {A}frican {C}raton ; {AFRIQUE} {DE} {L}'{OUEST}},
  booktitle = {},
  journal = {{P}recambrian {R}esearch},
  volume = {335},
  numero = {},
  pages = {art. 105450 [ p;]},
  ISSN = {0301-9268},
  year = {2019},
  DOI = {10.1016/j.precamres.2019.105450},
  URL = {https://www.documentation.ird.fr/hor/fdi:010077445},
}