Quartz to stishovite: Wave propagation in the mixed phase region

Grady, D. E.; Murri, W. J.; Fowles, G. R.

doi:10.1029/jb079i002p00332

Cited by 81 publications

(54 citation statements)

References 18 publications

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“…Based on earlier studies (Grady et al, 1974) on a similar density quartz rock, an elastic shock velocity of 6.2 km/s was assumed in order to perform Hugoniot analysis on the present compressive shock-waves.…”

Section: Experimental Results and Analysismentioning

confidence: 99%

Dynamic properties of ceramic materials

Grady¹,

Wise²

1993

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Section: Experimental Results and Analysismentioning

confidence: 99%

Dynamic properties of ceramic materials

Grady¹,

Wise²

1993

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“…It is deduced that diaplectic glass very likely forms after the compressional stage, during pressure release. Experimental studies of Ahrens et al (I969) and Grady et al (1974) on quartz, and Grady and Murri (1976) on feldspars show that a high-to-low density phase transition effectively occurs in some portion of the shocked constituents during pressure release. It can be concluded that fractures are formed at the end of the shock sequence, very likely during pressure release or after.…”

Section: Discussionmentioning

confidence: 99%

Fractures induced by shock in quartz and feldspar

Lambert¹

1979

Mineral. mag.

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SUMMARY. This study is devoted to fractures produced by natural and artificial shock processes in non-porous rocks consisting essentially of quartz and feldspar. Petrological and textural investigations were performed using optical and scanning electron microscopic techniques. A microfracturation index is adapted from Short (i966 , I968a, b) in order to compare the fracture densities in different materials shocked in different ways. In all cases, the density of fractures in quartz and feldspar increases with increasing pressure to about 200 kb. At higher pressure this trend is reversed. Fracturing is more intense in feldspar than in quartz. Plane shock waves produced in laboratory scale experiments induce more fracturing than natural shock waves. However, such an increase is no larger than the scatter among the data and the experimental technique used in the laboratory can be considered realistic in terms of fracturing. Finally the correlation between pressure and fracture density is too poor to be of use for quantitative pressure calibrations of naturally shocked materials.There is no direct correlation between the density of fractures and the number of planar elements observed. There is a negative correlation between fracturing and formation of diaplectic glass, Diaplectic glasses are remarkably weakly fractured compared with shocked minerals. The abrupt change in the slope of the curve giving the dependency of the density of fractures with pressure corresponds to the pressure at which diaplectic glass is formed. From petrographic considerations it is deduced that fracturing occurs at the end of the shock sequence, on pressure release, while diaplectic glasses are forming or already formed. Hypotheses of mechanical and thermal fracturing are examined; both are plausible, but a thermal origin may be preferred. The mechanism of formation of diaplectic glass is discussed with respect to results and deductions obtained by the study of fracturing. Diaplectic glass could represent a decompressed highdensity glass resulting from a single state transformation of a mineral, at high pressure, FRACTURES in minerals are a common feature of natural (impact craters ) and artificial shock events (chemical-nuclear explosions, laboratory scale impacts, etc.). However, as the same effects are often generated by endogenic processes and by static experiments, fractures due to impact are at the threshold of non-ambiguous shock features. Because of this, they are relatively poorly studied compared with other shock effects. We still do not Copyright the Mineralogical Society know exactly why, how, and when fractures occur in the minerals of shocked rocks. The purpose of this paper is to try to answer these questions, restricting the study to the behaviour of quartz and feldspar in non-porous rocks. Arguments will be supported by the examination of the correlations between fractures and the shock geometry, fractures and other shock effects, and also fractures and pressure. Previous studies have demonstrated a general increase in th...

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“…Efforts were undertaken to alleviate (or at least minimize) such gauge concerns. Perhaps most convincing was concurrent shock studies on quartz rock [7]. Comparable pressure level profiles in quartz exhibited no anomalous behavior.…”

Section: Structured Shock Waves In Dolomitementioning

confidence: 82%

Equation of state of dolomite from shock Hugoniot and static compression studies

Grady¹

2017

AIP Conference Proceedings

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Abstract.Comparisons are made between shock Hugoniot data and recent high-pressure static DAC (diamond anvil cell) data on dolomite mineral. Stark disparities are noted. DAC measurements reveal first order phase transformation within the pressure range of approximately 17-37 GPa. The preponderance of shock data failed to reveal phase transformation on the Hugoniot. Early time-resolved pressure reveal a possible transformation in the neighborhood of 20-25 GPa impeded by transformation kinetics. Static and dynamic data are contrasted and the underlying mechanisms assessed.

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Quartz to stishovite: Wave propagation in the mixed phase region

Cited by 81 publications

References 18 publications

Dynamic properties of ceramic materials

Dynamic properties of ceramic materials

Fractures induced by shock in quartz and feldspar

Equation of state of dolomite from shock Hugoniot and static compression studies

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