High Pressure Reactions Between Metals and Silicates: Implications for the Light Element in the Core and Core-Mantle Interactions

Hillgren, V. J.

doi:10.1180/minmag.1998.62a.1.329

Cited by 7 publications

(6 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Previous experimental studies by Knittle and Jeanloz [1991] reported that chemical reaction between liquid iron and (Mg,Fe)SiO 3 perovskite produced SiO 2 phase and metallic alloys of FeSi and FeO. In contrast, we observed no reaction products as stable phases other than iron‐rich metal and perovskite under the TEM, consistently with Hillgren and Boehler [1998]. It suggests that FeSiO 3 component in perovskite dissolved into molten iron without forming any other reaction products.…”

Section: Resultssupporting

confidence: 87%

“… Goarant et al [1992] reported similar observations at ∼70 and ∼130 GPa using analytical TEM. Hillgren and Boehler [1998] found that the dissolution of O and Si was enhanced with increasing pressure and temperature. In these earlier LHDAC studies, however, chemical compositions of liquid iron‐alloys were not quantitatively determined, due to the low space resolution of the scanning microprobe [ Knittle and Jeanloz , 1991; Hillgren and Boehler , 1998] and the difficulty in O analysis using EDS analytical system [ Goarant et al , 1992].…”

Section: Introductionmentioning

confidence: 99%

“… Hillgren and Boehler [1998] found that the dissolution of O and Si was enhanced with increasing pressure and temperature. In these earlier LHDAC studies, however, chemical compositions of liquid iron‐alloys were not quantitatively determined, due to the low space resolution of the scanning microprobe [ Knittle and Jeanloz , 1991; Hillgren and Boehler , 1998] and the difficulty in O analysis using EDS analytical system [ Goarant et al , 1992]. Here we quantitatively determined the O and Si contents in liquid iron to be in equilibrium with (Mg,Fe)SiO 3 perovskite up to 97 GPa and 3150 K by a combination of LHDAC and analytical TEM using both EDS and EELS spectra.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Solubilities of O and Si in liquid iron in equilibrium with (Mg,Fe)SiO₃ perovskite and the light elements in the core

Takafuji

Hirose

Mitome

et al. 2005

Geophysical Research Letters

134

View full text Add to dashboard Cite

Chemical reaction between liquid iron and (Mg,Fe)SiO3 perovskite was investigated by a combination of laser‐heated diamond anvil cell (LHDAC) and analytical transmission electron microscope (TEM). The compositions of quenched liquid iron in contact with perovskite were determined quantitatively using both energy‐dispersive (EDS) and electron energy loss (EELS) spectra. Results demonstrate that the dissolution both of O and Si into molten iron is significantly enhanced with increasing pressure. The quenched liquid iron contains 5.3 wt% O and 2.8 wt% Si at 97 GPa and 3150 K that can account for the 7% core density deficit. Reaction products such as SiO2, FeSi, and FeO were not observed as stable phases in this study. The bottom of the mantle in contact with outer core liquid could be depleted in iron. O and Si are important light elements in the core, whose contents may have increased over the geological time.

show abstract

Section: Resultssupporting

confidence: 87%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Solubilities of O and Si in liquid iron in equilibrium with (Mg,Fe)SiO₃ perovskite and the light elements in the core

Takafuji

Hirose

Mitome

et al. 2005

Geophysical Research Letters

134

View full text Add to dashboard Cite

show abstract

“…Samples from diamond cell experiments can be quantitatively analyzed using special sample preparation in combination with electron microprobes and ion probes (secondary ion mass spectrometry (SIMS)) [Hillgren and Boehler, 1998 …”

Section: Future Experimentsmentioning

confidence: 99%

High‐pressure experiments and the phase diagram of lower mantle and core materials

Boehler

2000

Reviews of Geophysics

383

256

View full text Add to dashboard Cite

Abstract. The interpretation of seismic data and computer modeling requires increased accuracy in relevant material properties in order to improve our knowledge of the structure and dynamics of the Earth's deep interior. To obtain such properties, a complementary method to classic shock compression experiments and theoretical calculations is the use of laser-heated diamond cells, which are now producing accurate data on phase diagrams, equations of state, and melting. Data on one of the most important measurements, the melting temperatures of iron at very high pressure, are now converging. Two other issues linking core properties to those of iron are investigated in the diamond cell: One is the melting point depression of iron in the presence of light elements, and the other is the structure of iron at the conditions of the inner core. First measurements on eutectic systems indicate a significant decrease in the melting point depression with increasing pressure, which is in contrast to previous predictions. X-ray diffraction measurements at simultaneously high pressure and high temperature have improved significantly with the installation of high-pressure "beam lines" at synchrotron facilities, and structural measurements on iron are in progress. Considerable efforts have been made to develop new techniques to heat minerals at the conditions of the deep mantle in the diamond cell and to measure their phase relations reliably. Even measurements of the melting behavior of realistic rock compositions at high pressure, previously considered to be impossible in the diamond cell, have been reported. The extrapolated solidus of the lower mantle intersects the geotherm at the core-mantle boundary, which may explain the seismically observed ultra low velocity zone. The diamond cell has great potential for future development and broad application, as new measurements on high-pressure geochemistry at deep mantle and core conditions have opened a new field of research. There are, however, strict experimental requirements for obtaining reliable data, which are summarized in the present paper. Results from recent measurements of melting temperatures and phase diagrams of lower mantle and core materials at very high pressure are reviewed. INTRODUCTIONThe interpretation of seismic data that have gained significantly in resolution and amount in the last few years poses a challenge in the fields of computer modeling, geochemistry, and experimental high-pressure research. A picture has evolved in which the Earth is much more heterogeneous in its internal structure than previously thought [Kellogg et al., 1999], and the causes for these heterogeneities are only poorly understood. The observed lateral and depth variations in seismic velocities may have thermal, structural, dynamical, and/or chemical causes. A key element in the understanding of this complexity is the study of physical and chemical properties of the relevant Earth materials. However, at the very high pressure and temperature conditions of the Earth's deep interior th...

show abstract

“… Knittle and Jeanloz [1989, 1991] and Goarant et al [1992] reported that (Mg, Fe)SiO 3 perovskite and metallic iron reacted to form SiO 2 and FeO, FeSi alloy. However, Hillgren and Boehler [1998] denied significant amount dissolution of silicon and oxygen into the metal up to 100 GPa. More recently, Takafuji et al [2004, 2005] reported that increase in solubility of silicon and oxygen into molten iron with pressure up to 97 GPa at around 3000 K. They also showed that dihedral angle between perovskite and molten iron, which indicates wetting property, decreases with increasing pressure to 47 GPa.…”

Section: Introductionmentioning

confidence: 99%

Interaction between iron and post‐perovskite at core‐mantle boundary and core signature in plume source region

Sakai¹,

Kondo²,

Ohtani³

et al. 2006

Geophysical Research Letters

View full text Add to dashboard Cite

Interaction between the lower mantle and core is essential for understanding the nature of D″ layer at the core‐mantle boundary (CMB). Here, we report the reaction between post‐perovskite (PPv) and metallic iron under the condition of the CMB, for example, 139 GPa and 3000 Kelvin. Analytical transmission electron microscope (ATEM) analysis revealed that significant amount of oxygen up to 6.3 weight percent (wt.%) and silicon up to 4.0 wt.% can be dissolved into molten iron. The dihedral angle between PPv and molten iron is 67 degrees. Thus, a small amount of core metal of about 2 volume percent (vol.%) can be trapped without separation in the PPv region at the CMB. The amount of core metal trapped by this mechanism can produce the isotopic signature of the outer core in the plume source at the base of the lower mantle.

show abstract

High Pressure Reactions Between Metals and Silicates: Implications for the Light Element in the Core and Core-Mantle Interactions

Cited by 7 publications

References 1 publication

Solubilities of O and Si in liquid iron in equilibrium with (Mg,Fe)SiO₃ perovskite and the light elements in the core

Solubilities of O and Si in liquid iron in equilibrium with (Mg,Fe)SiO₃ perovskite and the light elements in the core

High‐pressure experiments and the phase diagram of lower mantle and core materials

Interaction between iron and post‐perovskite at core‐mantle boundary and core signature in plume source region

Contact Info

Product

Resources

About

High Pressure Reactions Between Metals and Silicates: Implications for the Light Element in the Core and Core-Mantle Interactions

Cited by 7 publications

References 1 publication

Solubilities of O and Si in liquid iron in equilibrium with (Mg,Fe)SiO3 perovskite and the light elements in the core

Solubilities of O and Si in liquid iron in equilibrium with (Mg,Fe)SiO3 perovskite and the light elements in the core

High‐pressure experiments and the phase diagram of lower mantle and core materials

Interaction between iron and post‐perovskite at core‐mantle boundary and core signature in plume source region

Contact Info

Product

Resources

About

Solubilities of O and Si in liquid iron in equilibrium with (Mg,Fe)SiO₃ perovskite and the light elements in the core

Solubilities of O and Si in liquid iron in equilibrium with (Mg,Fe)SiO₃ perovskite and the light elements in the core