Stephen H. Kirby
R. S. Coe
1975
<div id="Abs1-section" class="c-article-section"><div id="Abs1-content" class="c-article-section__content"><p>Clinoenstatite (CE) was produced by deforming single-crystal specimens of ortho-enstatite (OE) in several different sorta of experiments. Examination with light and trans-mission electron microscopes shows that the transformation is coherent and involves a macroscopic shear on (100) [001] through an angle of 12.8±1.3 °, in good agreement with the theoretically expected value of 13.3 °, and that the transformation is accomplished by glide on (100) of partial dislocations with<span> </span><i>b</i>= 0.83[001]. Structural analysis provides further insight into the transformation mechanism. Reversion occurs in specimens annealed under a variety of conditions, and thin lamellae of CE in unconstrained, low-strain specimens recover their original shape during transformation back to OE. Our experiments and thermodynamic estimates both suggest that the equilibrium transition temperature is raised roughly 300 ° C per kilobar of shear stress on (100) [001]. This provides the basis of a method by which it may be possible to determine the magnitude as well as the orientation of the principal stresses that produce CE in nature during deformation of enstatite-bearing rocks.</p></div></div>
application/pdf
10.1007/BF00378000
en
Springer
The orthoenstatite to clinoenstatite transformation by shearing and reversion by annealing: Mechanism and potential applications
article