Post-perovskite phase transition and mineral chemistry in the pyrolitic lowermost mantle

Phase relations of a natural mantle composition were determined up to 126 GPa and 2450 K by in‐situ x‐ray diffraction measurements in a laser‐heated diamond‐anvil cell (LHDAC). MgSiO3‐rich perovskite (MgPv) transforms to a post‐perovskite phase (MgPP) at about 113 GPa and 2500 K (400‐km above the co...

Full description

Saved in:
Bibliographic Details
Published in:Geophysical research letters 2005-02, Vol.32 (3), p.np-n/a
Main Authors: Murakami, Motohiko, Hirose, Kei, Sata, Nagayoshi, Ohishi, Yasuo
Format: Article
Language:English
Subjects:
Chemical analysis
Diamonds
Diffraction
Geophysics
Iron
Mantle
Perovskites
Phase transformations
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Phase relations of a natural mantle composition were determined up to 126 GPa and 2450 K by in‐situ x‐ray diffraction measurements in a laser‐heated diamond‐anvil cell (LHDAC). MgSiO3‐rich perovskite (MgPv) transforms to a post‐perovskite phase (MgPP) at about 113 GPa and 2500 K (400‐km above the core‐mantle boundary) and the lowermost mantle consists of MgPP, (Mg, Fe)O magnesiowüstite (Mw), and CaSiO3‐rich perovskite (CaPv). Chemical analyses on recovered samples using transmission electron microscope (TEM) show that the distribution of iron significantly changes at the post‐perovskite phase transition. A strong enrichment of iron in Mw leads to the unique geophysical and geochemical properties of the lowermost mantle.
ISSN:0094-8276
1944-8007
DOI:10.1029/2004GL021956