Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Phase transformation of hydrous ringwoodite to the lower-mantle phases and the formation of dense hydrous silica

Journal Article · · American Mineralogist
DOI:https://doi.org/10.2138/am-2020-7261· OSTI ID:1780748
 [1];  [1];  [2];  [3];  [3];  [4];  [1]
  1. Arizona State Univ., Tempe, AZ (United States)
  2. Univ. of Chicago, IL (United States)
  3. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
  4. Carnegie Inst. of Washington, Washington, DC (United States)
In order to understand the effects of H2O on the mineral phases forming under the pressure-temperature conditions of the lower mantle, we have conducted laser-heated diamond-anvil cell experiments on hydrous ringwoodite (Mg2SiO4 with 1.1wt% H2O) at pressures between 29 and 59 GPa and temperatures between 1200 and 2400 K. Our experimental results show that hydrous ringwoodite (hRw) converts to crystalline dense hydrous silica, stishovite (Stv) or CaCl2-type SiO2 (mStv), containing 1 wt% H2O together with Brd and MgO at the pressure-temperature conditions expected for shallow lower-mantle depths between approximately 660 to 1600 km. Considering lack of sign for melting in our experiments, our preferred interpretation of the observation is that Brd partially breaks down to dense hydrous silica and periclase (Pc), forming Brd + Pc + Stv mineralogy. Our experiments may provide an explanation for the enigmatic coexistence of Stv and Fp inclusions in lower-mantle diamonds
Research Organization:
Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Basic Energy Sciences (BES)
Grant/Contract Number:
AC02-05CH11231
OSTI ID:
1780748
Alternate ID(s):
OSTI ID: 1659304
Journal Information:
American Mineralogist, Journal Name: American Mineralogist Journal Issue: 9 Vol. 105; ISSN 0003-004X
Publisher:
Mineralogical Society of AmericaCopyright Statement
Country of Publication:
United States
Language:
English

References (49)

LMFIT: Non-Linear Least-Square Minimization and Curve-Fitting for Python software September 2014
Intercomparison of the gold, platinum, and MgO pressure scales up to 140 GPa and 2500 K: EQUATIONS OF STATE OF AU, PT, AND MGO journal May 2017
Phase transition and equation of state of dense hydrous silica up to 63 GPa: DENSE HYDROUS PURE SILICA journal September 2017
High-pressure crystal chemistry of MgSiO3 perovskite journal June 1990
Studies of OH in nominally anhydrous minerals journal July 1996
The composition of the Earth journal March 1995
Water partitioning between nominally anhydrous minerals in the MgO–SiO2–H2O system up to 24 GPa: implications for the distribution of water in the Earth's mantle journal November 2000
Phase relations and melt compositions in CMAS–pyrolite–H2O system up to 25 GPa journal November 2002
The stability of hydrous silicates in Earth's lower mantle: Experimental constraints from the systems MgO–SiO2–H2O and MgO–Al2O3–SiO2–H2O journal December 2015
Mineralogy of the lower mantle: A review of ‘super-deep’ mineral inclusions in diamond journal January 2012
Equations of state of the high-pressure phases of a natural peridotite and implications for the Earth's lower mantle journal July 2004
Phase transition and density of subducted MORB crust in the lower mantle journal August 2005
FTIR thermochronometry of natural diamonds: A closer look journal November 2016
High pressure crystal chemistry of hydrous ringwoodite and water in the Earth’s interior journal June 2004
The global range of subduction zone thermal models journal November 2010
On origin of lower-mantle diamonds and their primary inclusions journal March 2014
Pressure dependence of H solubility in magnesiowüstite up to 25 GPa: Implications for the storage of water in the Earth's lower mantle: PRESSURE DEPENDENCE OF H SOLUBILITY IN MAGNESIOWÜSTITE journal May 2002
Transport of water into the lower mantle: Role of stishovite: TRANSPORT OF WATER INTO THE LOWER MANTLE journal January 2003
Water partitioning at 660 km depth and evidence for very low water solubility in magnesium silicate perovskite: WATER PARTITIONING journal September 2003
Maximum solubility of FeO in (Mg, Fe)SiO 3 -perovskite as a function of temperature at 26 GPa: Implication for FeO content in the lower mantle journal May 1996
Mineralogy and dynamics of a pyrolite lower mantle journal May 1998
The post-spinel transformation in Mg2SiO4 and its relation to the 660-km seismic discontinuity journal May 2001
Hydrous mantle transition zone indicated by ringwoodite included within diamond journal March 2014
Evidence for a Fe3+-rich pyrolitic lower mantle from (Al,Fe)-bearing bridgmanite elasticity data journal March 2017
Stability of hydrous silicate at high pressures and water transport to the deep lower mantle journal February 2014
Specific volume measurements of Cu, Mo, Pd, and Ag and calibration of the ruby R 1 fluorescence pressure gauge from 0.06 to 1 Mbar journal June 1978
The equation of state of dense argon: A comparison of shock and static studies journal July 1986
The post-stishovite phase transition in hydrous alumina-bearing SiO2 in the lower mantle of the earth journal August 2007
Ultrahydrous stishovite from high-pressure hydrothermal treatment of SiO2 journal December 2011
Stability of ferrous-iron-rich bridgmanite under reducing midmantle conditions journal June 2017
Equations of state of MgO, Au, Pt, NaCl-B1, and NaCl-B2: Internally consistent high-temperature pressure scales journal December 2007
Advanced flat top laser heating system for high pressure research at GSECARS: application to the melting behavior of germanium journal September 2008
DIOPTAS : a program for reduction of two-dimensional X-ray diffraction data and data exploration journal May 2015
GSAS-II : the genesis of a modern open-source all purpose crystallography software package journal March 2013
A beamline for high-pressure studies at the Advanced Light Source with a superconducting bending magnet as the source journal August 2005
Thermodynamic parameters in the Earth as determined from seismic profiles journal September 1981
A nearly water-saturated mantle transition zone inferred from mineral viscosity journal June 2017
Stability and Structure of MgSiO3 Perovskite to 2300-Kilometer Depth in Earth's Mantle journal September 2001
Dehydration melting at the top of the lower mantle journal June 2014
Stability of Perovskite (MgSiO3) in the Earth's Mantle journal November 1996
(Mg,Fe)SiO3-Perovskite Stability Under Lower Mantle Conditions journal June 1998
Ice-VII inclusions in diamonds: Evidence for aqueous fluid in Earth’s deep mantle journal March 2018
WATER, MELTING, AND THE DEEP EARTH H 2 O CYCLE journal May 2006
Inclusions in Sublithospheric Diamonds: Glimpses of Deep Earth journal March 2005
Structural systematics of hydrous ringwoodite and water in Earth’s interior journal October 2003
Equation of state of stishovite to lower mantle pressures journal February 2003
Formation of hydrous stishovite from coesite in high-pressure hydrothermal environments journal November 2016
Raman spectroscopy of water-rich stishovite and dense high-pressure silica up to 55 GPa journal November 2017
Cell assemblies for reproducible multi-anvil experiments (the COMPRES assemblies) journal January 2012

Similar Records

Quantification of water in hydrous ringwoodite
Journal Article · Tue Jan 27 19:00:00 EST 2015 · Frontiers in Earth Science · OSTI ID:1335510

Phase transition and equation of state of dense hydrous silica up to 63 GPa
Journal Article · Mon Jul 31 20:00:00 EDT 2017 · Journal of Geophysical Research. Solid Earth · OSTI ID:1409086

Sound velocities of hydrous ringwoodite to 16 GPa and 673 K
Journal Article · Thu May 10 00:00:00 EDT 2012 · Earth Planet. Sci. Lett. · OSTI ID:1038281