Titre du document / Document title

Large cold anomalies in the deep mantle and mantle instability in the Cretaceous

Auteur(s) / Author(s)

YUEN D. A. ⁽¹⁾ ; CADEK O. P. ; BOEHLER R. ; MOSER J. ; MATYSKA C. ;

Affiliation(s) du ou des auteurs / Author(s) Affiliation(s)

⁽¹⁾ Univ. Minnesota, dep. geology geophysics, Minnesota supercomputer inst., Minneapolis MN 55415-1227, ETATS-UNIS

Résumé / Abstract

Two large cold masses in the deep mantle have been delineated by using long-wavelength seismic tomographic models in conjunction with mineralogical experimental data at high pressure. These cold anomalies are found under the western Pacific and the Americas with temperatures more than 1000 degrees below the ambient mantle temperature. These strong cold anomalies existing in the lower mantle today would suggest that there might have existed not too long ago a substantial temperature lump across a thermal boundary layer between the upper and lower mantle. Numerical simulations in an axisymmetric spherical-shell model incorporating the two major phase transitions have shown that very large pools of cold material with temperatures of around 1500 K can be flushed down to the coremantle boundary during this tumultuous gravitational instability

Revue / Journal Title

Terra nova   ISSN 0954-4879 

Source / Source

1994, vol. 6, n^o3, pp. 238-245 (49 ref.)

Langue / Language

Anglais

Editeur / Publisher

Blackwell, Oxford, ROYAUME-UNI  (1989) (Revue)

Mots-clés anglais / English Keywords

Cretaceous ; mantle ; instability ; models ; wavelength ; tomography ; thermal anomalies ; West Pacific ; America ; digital simulation ; phase transitions ; correlation ; subduction ; transition zones ; convection ; Mesozoic ; Pacific Ocean ;

Mots-clés français / French Keywords

Crétacé ; Manteau ; Instabilité ; Modèle ; Longueur onde ; Tomographie ; Anomalie thermique ; Pacifique Ouest ; Amérique ; Simulation numérique ; Transition phase ; Corrélation ; Subduction ; Zone transition ; Convection ; Secondaire ; Océan Pacifique ;

Mots-clés espagnols / Spanish Keywords

Cretáceo ; Abrigo ; Modelo ; Tomografía ; Anomalía termal ; Pacífico Oeste ; America ; Simulación numérica ; Transición fase ; Correlación ; Subducción ; Zona transición ; Convección ; Secundario ; Océano Pacífico ;

Localisation / Location

INIST-CNRS, Cote INIST : 19534 A, 35400004024379.0020