@article{fdi:010019739,
  title = {{O}ceanic plateau and island arcs of {S}outhwestern {E}cuador : their place in the geodynamic evolution of {N}orthwestern {S}outh {A}merica},
  author = {{R}eynaud, {C}. and {J}aillard, {E}tienne and {L}apierre, {H}. and {M}amberti, {M}. and {M}ascle, {G}.{H}.},
  editor = {},
  language = {{ENG}},
  abstract = {{C}oastal {E}cuador is made up of an oceanic igneous basement overlain by {U}pper {C}retaceous to {L}ower {P}aleocene (approximately 98-60 {M}a) volcaniclastic and volcanic rocks of island-arc affinities. {T}he igneous basement, known as the {P}inon {F}ormation, locally dated at 123 {M}a, consists of olivine-free basalts and dolerites. {R}elative to {N}-{MORB}, both types of rocks exhibit high concentrations in {N}b (0.3-10.75 ppm), {T}a (0.03-0.67 ppm), {T}h (0.11-1.44 ppm), light and medium rare earth elements, and low {Z}r (22-105 ppm) and {H}f (0.59-2.8 ppm) contents, thus showing oceanic plateau basalts affinities. {M}ost of these oceanic plateau basalts tholeiites display rather homogeneous epsilon{N}d({T} = 123 {M}a) ratios (approximately +7), with the exception of two rocks with higher (+10) and lower (+4.5) epsilon{N}d({T} = 123 {M}a), respectively. {A}ll these basalts plot, with one exception, within the ocean island basalts field. {T}heir (87{S}r/86{S}r)i ratios are highly variable (0.7032-0.7048), probably due to hydrothermal oceanic alteration or assimilation of altered oceanic crust. {T}he rocks of the {P}inon {F}ormation are geochemically similar to the oceanic plateau tholeiites from {N}auru and {O}ntong {J}ava {P}lateaus and to the {U}pper {C}retaceous (92-88 {M}a) {C}arribbean {O}ceanic {P}lateau lavas. {T}he basalts and dolerites of the {U}pper {C}retaceous-{L}ower {P}aleocene island arcs show calc-alkaline affinities. {T}he epsilon{N}d ratios to {C}retaceous intra-oceanic are rocks from {N}orth, {C}entral and {S}outh {A}merica and from the {G}reater {A}ntilles. {S}ince the {P}inon oceanic plateau tholeiites are locally overlain by early-{L}ate {C}retaceous sediments (approximately 98-83 {M}a) and yielded locally an {E}arly {C}retaceous age, they do not belong to the {L}ate {C}retaceous {C}aribbean {O}ceanic {P}lateau. {T}he basement of coastal {E}cuador is interpreted as an accreted fragment of an overthickened and buoyant oceanic plateau... ({D}'apr{\`e}s r{\'e}sum{\'e} d'auteur)},
  keywords = {{ARC} {INSULAIRE} ; {CROUTE} {OCEANIQUE} ; {PLATEAU} ; {GEODYNAMIQUE} ; {ACCRETION} ; {BASALTE} ; {ROCHE} {IGNEE} ; {ANALYSE} {PETROGRAPHIQUE} ; {ANALYSE} {MINERALOGIQUE} ; {ANALYSE} {ISOTOPIQUE} ; {CORRELATION} ; {EVOLUTION} ; {CRETACE} ; {PALEOCENE} ; {ETUDE} {REGIONALE} ; {ANDES} ; {AMERIQUE} {DU} {SUD} ; {EQUATEUR} {SUD} {OUEST} ; {PINON} {PLATEAU}},
  booktitle = {},
  journal = {{T}ectonophysics},
  volume = {307},
  numero = {},
  pages = {235--254},
  ISSN = {0040-1951},
  year = {1999},
  DOI = {10.1016/{S}0040-1951(99)00099-2},
  URL = {https://www.documentation.ird.fr/hor/fdi:010019739},
}