Study of Oxygen Diffusion in Quartz by Activation Analysis

Schachtner, R.; Sockel, H. G.

doi:10.1007/978-1-4684-2340-2_87

Cited by 10 publications

(8 citation statements)

References 3 publications

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“…While the rates of hydrogen diffusion are clearly rapid enough for equilibration within experimental times, the uptake of molecular water by quartz appears to be limited by the much lower diffusion rates of oxygen (Figure 12). The lack of any significant oxygen exchange in our experiments at high P.•o (N-598 in Figure 7) is consistent with the collected results for oxygen diffusion measured over water pressures of •0-350 MPa [Haul and Diimbgen, 1962;Choudhury et al, 1965;Giletti et al, 1976;Schachtner and Sockel, 1977;Freer and Dennis, 1982;Dennis, 1984;Giletti and Yund, 1984]. Oxygen D values, measured at T = 800øC and P-2o = 100 MPa [Dennis, 1984;Giletti and Yund, 1984] yield characteristic diffusion penetration distances for oxygen into quartz of only • 1 /•m for an annealing time of 24 hours.…”

Section: Discussionsupporting

confidence: 91%

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Solubility and diffusional uptake of hydrogen in quartz at high water pressures: Implications for hydrolytic weakening

Kronenberg¹,

Kirby²,

Aines³

et al. 1986

J. Geophys. Res.

176

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Attempts to introduce molecular water into dry, natural quartz crystals by diffusive transport and thus weaken them hydrolytically at T = 700°-90(JOC and Pu,o = 400-1550 MPa have failed. Infrared spectroscopy of hydrothermally annealed single crystals of natural quartz reveals the diffusive uptake of interstitial hydrogen (resulting in hydroxyl groups) at rates similar to those previously proposed for intracrystalline water at high water pressures. The solubility of interstitial hydrogen at these conditions is independent of temperature and pressure; instead, it depends upon the initial aluminum concentration by the local charge neutrality condition [H, "] . Deformation experiments following hydrothermal annealing show no mechanical weakening, and the lack of any detectable broadband absorption associated with molecular water shows that the diffusion rates of structural water are much lower than those of hydrogen. These results are consistent with the available oxygen diffusion data for quartz and with the failure to observe weakening in previous studies of quartz deformation at pressures of 300-500 MPa; they call into question the rapid rates of diffusion originally suggested for the hydrolytic weakening defect. It is suggested that the observed weakening in many previous experiments was complicated by microcracking processes in response to nonhydrostatic stresses and low effective confining pressures. Extensive microcracking may prm:ide a mechanism for molecular water to enter quartz and allow local plastic deformation to occur. It does not appear that molecular water can diffuse far enough into uncracked quartz to allow hydrolytic weakening over annealing times that are feasible in the laboratory.

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Section: Discussionsupporting

confidence: 91%

“…The strength of quartz measured after -11 hours in talc approaches that reported by Griggs and Blacic [Biacic, 1971]; however, the yield strength after -112 hours in talc is again increa:;ed. [1962]; 2, Schachtner and Sockel [1977]; 3, Dennis [1984]; 4, Giletti and Yund [1984]; 5, Kats [1962]; 6, this study).…”

Section: Solubility and Diffusion Of Hydrogenmentioning

confidence: 68%

Solubility and diffusional uptake of hydrogen in quartz at high water pressures: Implications for hydrolytic weakening

Kronenberg¹,

Kirby²,

Aines³

et al. 1986

J. Geophys. Res.

176

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“…The next reported oxygen diffusion study was by Schachtner and Sockel (1977) who monitored the bulk exchange of 18 O in single crystals of natural quartz annealed in dry O 2 gas using nuclear reaction analysis. Their experiments were run at 870-1180 °C and the Arrhenius relation obtained is in reasonable agreement with the data of Haul and Dumbgen (1962), especially given the large potential systematic errors inherent in the bulk exchange technique (see Dennis 1984).…”

Section: Quartzmentioning

confidence: 99%

Oxygen and Hydrogen Diffusion in Minerals

Farver

2010

Reviews in Mineralogy and Geochemistry

106

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“…where t is the experimental duration and x is the diffusive path length, a minimum diffusion coefficient of 10 -•ø m 2 s -• is obtained for the mobile hydrogen defects. Measurements of oxygen diffusion in quartz under dry conditions [Haul and Durnbgen, 1962;Schachtner and Sockel, 1977] give diffusivities up to 6 orders of magnitude slower than under wet conditions at the same temperature [Gilletti and Yund, 1984;Dennis, 1984]. The measured self-diffusion coefficient for oxygen in dry forsteritc [Sockel et al, 1980;Reddy et al, 1980;Jaoul et al, 1980Jaoul et al, , 1983Ando et al, 1981] (Figure 16) is at least 9 orders of magnitude slower than the diffusion rate of the species that give rise to the sharp band and broadband hydroxyl features in the infrared spectrum at experimental temperatures from 1100 ø to 1300øC.…”

Section: • X2/t (2)mentioning

confidence: 99%

The role of water in the deformation of olivine single crystals

Kohlstedt²,

1985

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Hydrothermal treatment experiments have been performed on single crystals of San Carlos olivine at 1100 ø to 1300øC and 300-and 1500-MPa confining pressure, with the oxygen fugacity around the specimen constrained near the Fe/FeO buffer. The diffusion coefficients for the hydroxyl species giving rise to the sharp band and broadband features in the infrared spectrum of hydrothermally treated olivine have been determined to be greater than 10 -xø m 2 s -x under all pressure and temperature conditions tested; the solubility of the hydroxyl species seems to vary between crystals but to show little variability for specimens from the same crystal over the temperature range investigated at 300-MPa confining pressure. Crystals hydrothermally treated at 1300øC, 300-MPa confining pressure, and 10 -5 s -x strain rate are a factor of 1.5 to 2.5 weaker than those treated in an anhydrous environment. Microstructural investigations suggest that this reduction in strength is due to enhancement of the rate of climb of dislocations in the "wet" experiments. First-order calculations suggest a stress exponent of n --, 2.5 and a water fugacity exponent of m ,,, 1/5 for deformation under hydrous conditions, assuming that the deformation obeys a power law relation.Paper number 5B5577. 0148-0227/85/005B-5577505.00 in olivine. In addition, several preliminary hydrothermal treatment experiments were performed at 1500-MPa confining pressure to test the pressure sensitivity of the rates of diffusion and of the solubilities of hydroxyl species in olivine.In the following paragraphs the terms "water" and "hydrous" refer to any water-related species that may be involved in the phenomena being studied without particular identification of that species. The term "hydroxyl" refers to any species identified by infrared absorption in the 3-•m region. EXPERIMENTAL TECHNIQUES Specimen Preparation and CharacterizationSpecimens were cut from optically clear single crystals of olivine (Fo92) from San Carlos, Arizona, that were largely devoid of inclusions and imperfections other than millimeterspaced (100) and (001) low-angle boundaries. The crystals were oriented using a Laue back reflection X ray camera and were ground and polished with alumina powders giving orientation accuracies of approximately + 3 ø, limited predominantly by cumulative misorientation due to low-angle subgrain boundaries. Transmission electron microscope observations were carried out on ion-thinned samples in a Siemens 102 electron microscope operating at 125 kV.The introduction or removal of hydroxyl species from the olivine due to heat treatment was monitored using unpolarized room temperature infrared absorption spectra, obtained using a Pye Unicam SP3-200 ratio-recording grating spectrometer with digital data acquisition. For several samples, spectra were measured at liquid nitrogen temperature for comparison with the room temperature results. Spectra corresponding to the introduced or removed hydroxyl species were determined by subtracting the spectrum of an untreated specimen...

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Study of Oxygen Diffusion in Quartz by Activation Analysis

Cited by 10 publications

References 3 publications

Solubility and diffusional uptake of hydrogen in quartz at high water pressures: Implications for hydrolytic weakening

Solubility and diffusional uptake of hydrogen in quartz at high water pressures: Implications for hydrolytic weakening

Oxygen and Hydrogen Diffusion in Minerals

The role of water in the deformation of olivine single crystals

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