Stability of magnesite and its high-pressure form in the lowermost mantle

Maiko Isshiki, Tetsuo Irifune, Kei Hirose, Shigeaki Ono, Yasuo Ohishi, Tetsu Watanuki, Eiji Nishibori, Masaki Takata, Makoto Sakata

Research output: Contribution to journalArticlepeer-review

196 Citations (Scopus)

Abstract

Carbonates are important constituents of marine sediments and play a fundamental role in the recycling of carbon into the Earth's deep interior via subduction of oceanic crust and sediments. Study of the stability of carbonates under high pressure and temperature is thus important for modelling the carbon budget in the entire Earth system. Such studies, however, have rarely been performed under appropriate lower-mantle conditions and no experimental data exist at pressures greater than 80 GPa (refs 3-6). Here we report an in situ X-ray diffraction study of the stability of magnesite (MgCO3), which is the major component of subducted carbonates, at pressure and temperature conditions approaching those of the core-mantle boundary. We found that magnesite transforms to an unknown form at pressures above ∼115 GPa and temperatures of 2,100-2,200 K (depths of ∼2,600 km) without any dissociation, suggesting that magnesite and its high-pressure form may be the major hosts for carbon throughout most parts of the Earth's lower mantle.

Original languageEnglish
Pages (from-to)60-63
Number of pages4
JournalNature
Volume427
Issue number6969
DOIs
Publication statusPublished - 2004 Jan 1
Externally publishedYes

ASJC Scopus subject areas

  • General

Fingerprint Dive into the research topics of 'Stability of magnesite and its high-pressure form in the lowermost mantle'. Together they form a unique fingerprint.

Cite this