Journal ArticleDOI
Dislocations associated with optical features in naturally-deformed olivine
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In this paper, the dislocations are arranged in arrays forming low-angle sub-boundaries which have been identified with features observed in the optical microscope, and a comparison of this dislocation substructure with that observed in olivine and in metals, experimentally deformed under various conditions, suggests that the deformation in nature has occurred by creep.Abstract:
Transmission electron microscopy has been used for the direct observation of dislocations in naturally-deformed olivine. The dislocations are arranged in arrays forming low-angle sub-boundaries which have been identified with features observed in the optical microscope. Comparison of this dislocation substructure with that observed in olivine, and in metals, experimentally deformed under various conditions, suggests that the deformation in nature has occurred by creep. Possible mechanisms of creep, involving the cooperative glide and climb of dislocations, are discussed.read more
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Book
A Practical Guide to Rock Microstructure
TL;DR: In this article, a glossary of microstructural terms for sedimentary and metamorphic rocks is presented, along with a discussion of the relationship between sedimentary, igneous and deformed rocks.
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Low-stress high-temperature creep in olivine single crystals
David L. Kohlstedt,C. Goetze +1 more
TL;DR: In this paper, a flow law of the form e˙ = ƒ(σ) exp (−Q/RT) is obtained, where σ is an empirical function that is not simply proportional to σn for constant n and Q is equal to 125 ± 5 kcal/mol.
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Steady state flow of rocks
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New Technique for Decorating Dislocations in Olivine
TL;DR: This simple dislocation decoration technique greatly reduces the cost and time involved in surveying the dislocation structures of deformed olivine crystals and opens the way to a more thorough understanding of the deformation of this important geologic material.
References
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Journal ArticleDOI
Phase contrast, a new method for the microscopic observation of transparent objects
TL;DR: In this paper, the Abbe method is used to calculate the image of a coarse transparent grating with shallow grooves of arbitrary form (phase grating), and the effect of the diffraction by the phase strip is considered and practical methods discussed to make the resulting diffraction-halo as faint as possible.
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Hydrolytic Weakening of Quartz and Other Silicates
TL;DR: Griggs and Blacic as discussed by the authors showed that water-weakened synthetic quartz deforms at a critical temperature dependent on the water content, varying from 380°C at 0.13% to 1070°C with a rate of 0.0015%.
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The creep strength of the Earth's mantle
TL;DR: In this paper, it was shown that at stresses greater than about 10−2 bar creep in the earth's mantle is caused by dislocation motion rather than by the mass transport of atoms through diffusion from one grain boundary to another.
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Mechanisms of plastic deformation of olivine
TL;DR: In this article, the active slip system of terrestrial olivine was determined from microscopic study of slip bands, deformation lamellas and kink bands, and it was shown that at temperatures less than 1000°C, slip on {0kl} [100], pencil glide in [100, the system shown here to be predominant in naturally deformed terrestrial Olivine, occurs in addition to the system {110} [001] and becomes the predominant mechanism with decreasing strain rate.
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Thin foils of non-metals made for electron microscopy by sputter-etching
TL;DR: In this paper, the preparation of foils by sputter-etching is described and the effects on the sample of ion current density, and angle of ion incidence are discussed.