Sharpness of the D'' discontinuity beneath the Cocos Plate: Implications for the perovskite to post-perovskite phase transition

Details Sharpness of the D'' discontinuity beneath the Cocos Plate: Implications for the perovskite to post-perovskite phase transition Sharpness of the D'' discontinuity beneath the Cocos Plate: Implications for the perovskite to post-perovskite phase transition

Feb 2008

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2008georl..3503304l&link_type=abstract

Geophysical Research Letters, Volume 35, Issue 3, CiteID L03304

Physics

11

Tectonophysics: Earth'S Interior: Composition And State (1212, 7207, 7208, 8105), Seismology: Mantle (1212, 1213, 8124), Seismology: Body Waves, Mineral Physics: Elasticity And Anelasticity, Mineral Physics: High-Pressure Behavior

Scientific paper

The depth extent, or sharpness, of the D'' seismic velocity discontinuity is determined by modeling distance-dependence of reflected S-wave signals sampling the lowermost mantle beneath the Cocos Plate. The data, spanning distances from 64° to 83° and grouped in two small turning-point bins from 5° to 10°N and 10° to 15°N, are compatible with a sharp 1 to 2% shear velocity increase near 300 km above the core-mantle boundary, but not with reflection from a transition zone extending more than ~30 km in depth. Interpretation of the velocity structure as the result of magnesium-silicate perovskite undergoing a phase transition to post-perovskite requires limited presence of Al and Fe, which will broaden the phase transition. Current experiments indicate that the phase transition may occur over ~5 GPa (90 km) in pyrolitic material, requiring either distinct chemistry or dynamical mechanisms to sharpen the phase transition for this high-velocity sub-circum-Pacific region.

Affiliated with

Also associated with

No associations

Rating

Sharpness of the D'' discontinuity beneath the Cocos Plate: Implications for the perovskite to post-perovskite phase transition does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Sharpness of the D'' discontinuity beneath the Cocos Plate: Implications for the perovskite to post-perovskite phase transition, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Sharpness of the D'' discontinuity beneath the Cocos Plate: Implications for the perovskite to post-perovskite phase transition will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1320314