Hydrous Phases and Hydrogen Bonding at High Pressure

Prewitt, C. T.; Parise, John B.

doi:10.2138/rmg.2000.41.11

Cited by 18 publications

(10 citation statements)

References 144 publications

(184 reference statements)

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“…In materials of the near-surface environment (e.g. crustal minerals and fluids), hydrogen is commonly incorporated as OH − and H 2 O, with "free" protons usually considered bound as H 3 O + , H 5 O 2 + , and NH 4 + (Hawthorne 1992, Prewitt & Parise 2000. As noted below, the incorporation of hydrogen as hydroxyl can form relatively dense structures that are directly related to equivalent anhydrous structures by simple substitution and/or crystallographic shearing mechanisms , Prewitt & Parise 2000.…”

Section: Structure and Bonding Of Hydrogenmentioning

confidence: 99%

“…If the amount of hydrogen found in these phases is representative of the entire mantle, then a volume of water at least as large as the current oceans could be retained within Earth's silicate mantle without the presence of separate hydrous phases at depth. Moreover, new classes of dense hydrous phases have been discovered (Prewitt & Parise 2000). Furthermore, recent experiments provide possible new constraints on the abundance of hydrogen (along with other light elements) in the core (e.g.…”

Section: Introductionmentioning

confidence: 99%

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Hydrogen in the Deep Earth

Williams

Hemley

2001

Annu. Rev. Earth Planet. Sci.

247

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The mechanisms of exchange of hydrogen between the deep interior and surface of Earth, as well as the means of retention and possible abundance of hydrogen deep within the Earth, are examined. The uppermost several hundred kilometers of Earth's suboceanic upper mantle appear to be largely degassed, but significant primordial hydrogen could be retained within the transition zone, lower mantle, or core. Regassing of the planet occurs via subduction: Cold slabs are likely particularly efficient at transporting hydrogen to depth within the planet. Marked changes in hydrogen cycling have taken place throughout Earth's history: Evidence of hydrated ultramafic melts in the Archean and probable hydrogen retention within a Hadean magma ocean indicate that early in its history, the deep Earth was substantially wetter. The largest enigma associated with hydrogen in the deep Earth lies in the core: This region could represent the dominant reservoir of hydrogen on the planet, with up to ∼100 hydrospheres of hydrogen present as a high-pressure iron-alloy.

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Section: Structure and Bonding Of Hydrogenmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Hydrogen in the Deep Earth

Williams

Hemley

2001

Annu. Rev. Earth Planet. Sci.

247

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“…The potential storage of water in the Earth's deep interior is an issue of continued pursuit because the presence of water may significantly affect the phase relations and various physical properties such as viscosity, density, and electrical conductivity (Prewitt and Parise 2000). In the MgO-SiO 2 -H 2 O system, which represents a simplified model system for mantle minerals, several high-pressure hydrous phases (so-called dense hydrous magnesium silicates, DHMS) have been discovered experimentally, including phase A, B, superhydrous B (=C), E, and D (=F, G) (cf.…”

Section: Introductionmentioning

confidence: 99%

Dense hydrous magnesium silicates, phase D, and superhydrous B: New structural constraints from one- and two-dimensional 29Si and 1H NMR

Xue

Kanzaki

Shatskiy

2008

American Mineralogist

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To gain new structural insights into phase D and superhydrous B, two phases of potential mantle water reservoir, we have applied a range of one-(1D) and two-dimensional (2D) 1 H and 29 Si NMR techniques, as well as Raman spectroscopy, to samples synthesized at 24 GPa and 900~1100 °C. These data have revealed that phase D is characterized by disordered and varying local structures around both Si and H. The 29 Si NMR spectra of phase D contain a nearly symmetric, broad peak near -177.7 ppm, attributable to octahedral Si with local structural disorder. The high-resolution 1 H CRAMPS spectra of phase D contain a main broad peak near 12.6 ppm with shoulders near 10 and 7 ppm, suggesting a distribution of hydrogen bonding distances. For superhydrous B, our comprehensive 2D 1 H and 29 Si NMR results have clearly revealed that it contains dissimilar hydrogen (H1-H2) pairs and one tetrahedral Si site, consistent with space group Pnn2.

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“…The compression behavior of hydrous minerals can provide fundamental information on global phenomena occurring in the Earth's interior, such as dehydration of the subducting slab, deep-focused earthquakes, and water storage in the mantle (e.g., Prewitt and Parise 2000;Williams and Hemley 2001). The structural response of the hydrogen bond to high pressure is relevant to studies of pressure-induced phase transitions of hydrous materials.…”

Section: Introductionmentioning

confidence: 99%

Pressure-induced phase transformation of kalicinite (KHCO₃) at 2.8 GPa and local structural changes around hydrogen atoms

Kagi

Nagai

Loveday

et al. 2003

American Mineralogist

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The pressure-induced structural phase transition in kalicinite, KHCO 3 , has been studied by neutron powder diffraction, and infrared (IR) and Raman spectroscopy at high pressure and room temperature. The neutron diffraction study of deuterated kalicinite (KDCO 3 ) revealed that for the one site for hydrogen (deuterium) found in the low-pressure phase, the O-D◊◊◊O angle decreases from 176 to 161∞ and the distance between donor and acceptor O atoms of the O-D◊◊◊O group decreases from 2.66 to 2.59 Å in the pressure range from 0 to 2.5 GPa. The crystal structure of the high-pressure polymorph was not determined. Infrared spectra were obtained at pressures up to 6.3 GPa using a diamond anvil cell. At ambient pressure, the O-H stretching, O-H◊◊◊O in-plane bending, and O-H◊◊◊O out-of-plane bending modes occur at 2620, 1405, and 988 cm -1 , respectively. The frequency of the O-H stretch mode was nearly constant in the pressure range from 0 to 2.8 GPa, while that of O-H◊◊◊O in-plane bending and out-of-plane modes increased with increasing pressure up to 2.8 GPa and remained constant above the phase transition pressure. The Raman spectra showed a clear phase transition at 2.8 GPa. The three Raman modes observed are assigned to internal vibrational modes of HCO 3 -and this suggests that the surrounding environment did change dramatically at the phase transition. These results suggest that the phase transition in kalicinite is triggered by the distortion of C-O-H bond at high pressure.Brought to you by | New York University Bobst Library Technical Services Authenticated Download Date | 7/14/15 8:40 AM FIGURE 8. Peak position vs. pressure for Raman spectra of kalicinite. The open and filled symbols represent data obtained with increasing and decreasing pressure, respectively. (a) The combination of the C = O1 and C-O3 stretches. (b) The combination of in-plane bending of O2-C-O3 and stretching of C-O2 and in-plane bending of C = O1.

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Hydrous Phases and Hydrogen Bonding at High Pressure

Cited by 18 publications

References 144 publications

Hydrogen in the Deep Earth

Hydrogen in the Deep Earth

Dense hydrous magnesium silicates, phase D, and superhydrous B: New structural constraints from one- and two-dimensional 29Si and 1H NMR

Pressure-induced phase transformation of kalicinite (KHCO₃) at 2.8 GPa and local structural changes around hydrogen atoms

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Hydrous Phases and Hydrogen Bonding at High Pressure

Cited by 18 publications

References 144 publications

Hydrogen in the Deep Earth

Hydrogen in the Deep Earth

Dense hydrous magnesium silicates, phase D, and superhydrous B: New structural constraints from one- and two-dimensional 29Si and 1H NMR

Pressure-induced phase transformation of kalicinite (KHCO3) at 2.8 GPa and local structural changes around hydrogen atoms

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Pressure-induced phase transformation of kalicinite (KHCO₃) at 2.8 GPa and local structural changes around hydrogen atoms