Metamorphic evolution of subducted hot oceanic crust (la corea mélange, cuba)


Abstract:

Thermobarometric estimates and pbkp_redictions of theoretical and experimental isochemical P-T phase diagrams for epidote±garnet amphibolite blocks from the serpentinite mélange of La Corea (eastern Cuba) indicate partial melting of subducted oceanic lithosphere occurred at peak metamorphic conditions of ca. 700 °C and 14 to 15 kbar. These anomalously high geothermal conditions suggest onset of subduction of young oceanic lithosphere of the Proto-Caribbean. The amphibolites have basaltic composition and MORB affinity. Partial melting produced tonalitictrondhjemitic- granitic melts that crystallized at depth associated with the amphibolites. Calculated retrograde conditions for the amphibolites (450 °C and 8-10 kbar) indicate counterclockwise P-T paths during exhumation in the subduction channel, in agreement with published pbkp_redictions on thermo-mechanical modeling of onset of subduction of young lithosphere. These findings have important consequences for the plate tectonic configuration of the Caribbean realm since they corroborate the existence of fragments of early subducted young oceanic lithosphere in the eastern Cuba mélanges that indicate subduction of an oceanic ridge during mid-Cretaceous times.

Año de publicación:

2010

Keywords:

  • Caribbean plate
  • subduction channel
  • Partial melting
  • amphibolite

Fuente:

scopusscopus

Tipo de documento:

Article

Estado:

Acceso restringido

Áreas de conocimiento:

    Áreas temáticas:

    • Petrología