Fig. 1: Stressed zircon inclusions within garnet (ZiG) under high temperature.

a Difference in the measured peak position (Δω) of a zircon inclusion in garnet from a free crystal at the same temperature during two consecutive heating-cooling cycles as determined from in situ high-temperature Raman spectroscopy at ambient pressure (average error bar ±0.49 cm⁻¹ and 0.1 K). b Volume strain of the inclusion calculated from the measured Δω (average error bar ±4E−04 and 0.1 K). Solid and dashed lines are volume strain predictions from elastic models. Because the peak position and volume strain are not reversible, these trends represent non-elastic processes occurring on the time scale of laboratory experiments. Raman spectra on the inclusion were collected with a laser power < 14 mW to avoid laser heating of the inclusion during measurements (e.g. ref. ¹²). c Optical micrographs under plane-polarized light of a zircon inclusion within garnet showing dislocation-like textures developed on heating, when garnet was under tensile stress conditions, and preserved on subsequent cooling to room temperature.