Evidence for post-depositional diffusional loss of hydrogen in quartz phenocryst fragments within ignimbrites

Bíró, Tamás; Kovàcs, István; Karátson, Dávid; Stalder, Roland; Király, Edit; Falus, György; Fancsik, Tamás; Sándorné, Judit K.

doi:10.2138/am-2017-5861

Cited by 12 publications

(22 citation statements)

References 58 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In addition, further experiments at low pressure (e.g., 0.2 and 0.5 kbar) should be performed to confirm the predicted rapid increase from 1 bar to 1 kbar. Results from these experiments would also be applicable to quartz bearing volcanic systems (Biro et al 2017; Tollan et al 2019).…”

Section: Discussionmentioning

confidence: 99%

OH defect contents in quartz in a granitic system at 1–5 kbar

Potrafke

Stalder

Schmidt

et al. 2019

Contrib Mineral Petrol

Self Cite

View full text Add to dashboard Cite

Quartz is able to incorporate trace elements (e.g., H, Li, Al, B) depending on the formation conditions (P, T, and chemical system). Consequently, quartz can be used as a tracer for petrogenetic information of silicic plutonic bodies. In this experimental study, we provide the first data set on the OH defect incorporation in quartz from granites over a pressure/temperature range realistic for the emplacement of granitic melts in the upper crust. Piston cylinder and internally heated pressure vessel synthesis experiments were performed in a water-saturated granitic system at 1–5 kbar and 700–950 °C. Crystals from successful runs were analysed by secondary ion mass spectrometry (SIMS) and Fourier transform infrared (FTIR) spectroscopy, and their homogeneity was verified by FTIR imaging. IR absorption bands can be assigned to specific OH defects and analysed qualitatively and quantitatively and reveal that (1) the AlOH band triplet at 3310, 3378 and 3430 cm−1 is the dominating absorption feature in all spectra, (2) no simple trend of total OH defect incorporation with pressure can be observed, (3) the LiOH defect band at 3470–3480 cm−1 increases strongly in a narrow pressure interval from 4 kbar (220 µg/g H2O) to 4.5 kbar (500 µg/g H2O), and declines equally strong towards 5 kbar (180 µg/g H2O). Proton incorporation is charge balanced according to the equation H+ + A+ + P5+ = M3+ + B3+, with A+ = alkali ions and M3+ = trivalent metal ions.

show abstract

Section: Discussionmentioning

confidence: 99%

OH defect contents in quartz in a granitic system at 1–5 kbar

Potrafke

Stalder

Schmidt

et al. 2019

Contrib Mineral Petrol

Self Cite

View full text Add to dashboard Cite

show abstract

“…In silicates, the so-called hydrogarnet-or hydrogrossular-type defect ((4H) × Si ) corresponds to the substitution of four protons for one Si 4+ ion. Occurrence of this type of defect has been either reported or proposed in, for example, garnet (e.g., Nobes et al, 2000; Geiger and Rossman, 2018), zircon (Nasdala et al, 2001;Balan et al 2013), forsterite (Lemaire et al, 2004;Berry et al, 2005;Balan et al, 2011Balan et al, , 2017Padrón-Navarta et al, 2014) and ringwoodite (Blanchard et al, 2009). In quartz, a band at 3585 cm −1 with polarization in the (001) plane, in samples experimentally synthesized in the quartz-water system, has been associated with the (4H) ×…”

Section: Methodsmentioning

confidence: 95%

“…Quantum-mechanical modeling tools can also be used to investigate the vibrational spectroscopic properties of models of OH defects that can be tested against experimental observations. This approach has been successfully used to interpret the infrared spectrum of OH defects in a number of silicate-group minerals (e.g., Blanchard et al, 2009Blanchard et al, , 2017Balan et al, 2011Balan et al, , 2013Balan et al, , 2017Ingrin et al, 2014). In the present study, we compute the theoretical infrared (IR) absorption spectrum of selected models of OH defects in quartz, focusing on OH defects potentially occurring in natural quartz.…”

Section: Introductionmentioning

confidence: 99%

Structure and theoretical infrared spectra of OH defects in quartz

2020

View full text Add to dashboard Cite

Abstract. The infrared spectra of natural quartz, and synthetic quartz produced in conditions relevant to natural environments, generally contain some association of OH-stretching absorption bands at 3596, 3585, 3483, 3431, 3379 and 3313 cm−1, and/or a broad band at ∼ 3400 cm−1. In this study, a series of OH-bearing defects has been theoretically investigated from first principles within the density functional theory framework. The optimized structure, infrared spectroscopic properties and relative energy of defect configurations have been determined. Comparison with experimental observations enables the identification of atomic-scale configurations related to the experimentally observed OH-stretching bands. Consistent with previous interpretations, the results confirm the assignment of the bands at 3596 and 3483 cm−1 to OH defects associated with B3+ substituting for Si4+ and to OH defects associated with Li+ cations located in the structural channels, respectively. They also confirm the assignment of the bands at 3313 and 3379 cm−1 to OH associated with the Al3+-for-Si4+ substitution and, by implication, the previously given interpretation of the 3431 cm−1 band in terms of Fermi resonance. The band at 3585 cm−1 does not appear to be related to a hydrogarnet-type defect, as has been proposed previously, but potentially corresponds to isolated OH− groups bridging two Si atoms, where the charge compensation is ensured by a nonlocal mechanism.

show abstract

“…Total H 2 O contents appear unmodified. In addition, the diffusive exchange of hydrogen is very slow in quartz at ambient conditions, <10 −17.5 m 2 ·s −1 , although better calibrations for both D and H await future experimental constraints (e.g., Biró et al., 2017). Nevertheless, the inclusion data do not plot along a rehydration evolution trend (Figure 8).…”

Section: Discussionmentioning

confidence: 99%

Hydrogen Isotope Composition of a Large Silicic Magma Reservoir Preserved in Quartz‐Hosted Glass Inclusions of the Bishop Tuff Plinian Eruption

Befus

Walowski

Hervig

et al. 2020

Geochem Geophys Geosyst

View full text Add to dashboard Cite

The crystal cargo of a magma provides an in situ record of magmatic volatiles and degassing. The stability of hydrous minerals, such as mica and amphibole, is dictated by the presence and fugacity of magmatic water. Minerals may also entrap small parcels of magma during crystal growth, preserved as glass inclusions. Following entrapment, the crystal host provides a protective jacket that ideally preserves the compositional integrity of the original melt during quenching to glass during eruption and emplacement. Major and trace element studies of such inclusions have transformed our understanding of preeruptive magmatic processes, having been used to explore crystallization processes, conduit ascent rates, and degassing (e.g., Blundy &

show abstract

Evidence for post-depositional diffusional loss of hydrogen in quartz phenocryst fragments within ignimbrites

Cited by 12 publications

References 58 publications

OH defect contents in quartz in a granitic system at 1–5 kbar

OH defect contents in quartz in a granitic system at 1–5 kbar

Structure and theoretical infrared spectra of OH defects in quartz

Hydrogen Isotope Composition of a Large Silicic Magma Reservoir Preserved in Quartz‐Hosted Glass Inclusions of the Bishop Tuff Plinian Eruption

Contact Info

Product

Resources

About