Textures Induced by the Coesite‐Stishovite Transition and Implications for the Visibility of the X‐Discontinuity

Abstract

The X-discontinuity, also known as the "300 km discontinuity," is a recurrent feature in the upper mantle at 250-350 km depth that has been extensively investigated in the past (e.g., Deuss & Woodhouse, 2002;Pugh et al., 2021;Revenaugh & Jordan, 1991;Williams & Revenaugh, 2005 and references therein). The discontinuity is seismically detected by an impedance contrast of 3%-8% in both P-and S-waves (e.g., Bagley & Revenaugh, 2008) and while it does not seem to be a global feature, its occurrence is widespread. Detections have been reported beneath continents (

Deformation Mechanisms, Microstructures, and Seismic Anisotropy of Wadsleyite in the Earth's Transition Zone

“…The detailed procedure has been described in Rosa et al. (2015) and used in several publications (Chandler, Bernier, et al., 2021; Chandler, Devoe, et al., 2021; Gay et al., 2023; Krug et al., 2022; Langrand et al., 2017; Rosa et al., 2016).…”

“…The data are then processed to (a) separate the individual diffraction spots of the grains of the sample large enough to produce a single-crystallike signal, from the rest of the signals, which includes powder-like diffraction signal of the smaller sample grains, signal from the pressure medium, diamond Compton scattering, etc., (b) identify these extracted diffraction spots, and (c) determine the grain orientation matrices. The detailed procedure has been described in Rosa et al (2015) and used in several publications (Chandler, Bernier, et al, 2021;Chandler, Devoe, et al, 2021;Gay et al, 2023;Krug et al, 2022;Langrand et al, 2017;Rosa et al, 2016).…”