@article{PAR00007399,
  title = {{V}olcanic markers of the post-subduction evolution of {B}aja {C}alifornia and {S}onora, {M}exico : slab tearing versus lithospheric rupture of the {G}ulf of {C}alifornia},
  author = {{C}almus, {T}. and {P}allares, {C}. and {M}aury, {R}.{C}. and {A}guillón-{R}obles, {A}. and {B}ellon, {H}. and {B}enoit, {M}. and {M}ichaud, {F}ran{\c{c}}ois},
  editor = {},
  language = {{ENG}},
  abstract = {{A}bstract?{T}he study of the geochemical compositions and {K}-{A}r or {A}r-{A}r ages of ca. 350 {N}eogene and {Q}uaternary lavas from {B}aja {C}alifornia, the {G}ulf of {C}alifornia and {S}onora allows us to discuss the nature of their mantle or crustal sources, the conditions of their melting and the tectonic regime prevailing during their genesis and emplacement. {N}ine petrographic/geochemical groups are distinguished: ??regular' calc-alkaline lavas; adakites; magnesian andesites and related basalts and basaltic andesites; niobium-enriched basalts; alkali basalts and trachybasalts; oceanic ({MORB}-type) basalts; tholeiitic/transitional basalts and basaltic andesites; peralkaline rhyolites (comendites); and icelandites. {W}e show that the spatial and temporal distribution of these lava types provides constraints on their sources and the geodynamic setting controlling their partial melting. {T}hree successive stages are distinguished. {B}etween 23 and 13 {M}a, calc-alkaline lavas linked to the subduction of the {P}acific-{F}arallon plate formed the {C}omonduŽ and central coast of the {S}onora volcanic arc. {I}n the extensional domain of western {S}onora, lithospheric mantle-derived tholeiitic to transitional basalts and basaltic andesites were emplaced within the southern extension of the {B}asin and {R}ange province. {T}he end of the {F}arallon subduction was marked by the emplacement of much more complex {M}iddle to {L}ate {M}iocene volcanic associations, between 13 and 7 {M}a. {C}alc-alkaline activity became sporadic and was replaced by unusual post-subduction magma types including adakites, niobium-enriched basalts, magnesian andesites, comendites and icelandites. {T}he spatial and temporal distribution of these lavas is consistent with the development of a slab tear, evolving into a 200-km-wide slab window sub-parallel to the trench, and extending from the {P}acific coast of {B}aja {C}alifornia to coastal {S}onora. {T}holeiitic, transitional and alkali basalts of subslab origin ascended through this window, and adakites derived from the partial melting of its upper lip, relatively close to the trench. {C}alcalkaline lavas, magnesian andesites and niobium-enriched basalts formed from hydrous melting of the supraslab mantle triggered by the uprise of hot {P}acific asthenosphere through the window. {D}uring the {P}lio-{Q}uaternary, the ??no-slab' regime following the sinking of the old part of the {F}arallon plate within the deep mantle allowed the emplacement of alkali and tholeiitic/transitional basalts of deep asthenospheric origin in {B}aja {C}alifornia and {S}onora. {T}he lithospheric rupture connected with the opening of the {G}ulf of {C}alifornia generated a high thermal regime associated to asthenospheric uprise and emplaced {Q}uaternary depleted {MORB}-type tholeiites. {T}his thermal regime also induced partial melting of the thinned lithospheric mantle of the {G}ulf area, generating calcalkaline lavas as well as adakites derived from slivers of oceanic crust incorporated within this mantle.},
  keywords = {{S}lab tearing ; slab melting ; ridge-trench collision ; adakite ; basalt ; comendite ; magnesian andesite ; asthenospheric window ; basin and range ; {G}ulf of {C}alifornia ; {B}aja {C}alifornia ; {S}onora ; {M}exico ; {MEXIQUE}},
  booktitle = {},
  journal = {{P}ure and {A}pplied {G}eophysics},
  volume = {168},
  numero = {8-9},
  pages = {1303--1330},
  year = {2011},
  DOI = {10.1007/s00024-010-0204-z},
  URL = {https://www.documentation.ird.fr/hor/{PAR}00007399},
}