Cubic zirconia in >2370 °C impact melt records Earth's hottest crust

- Zircon has partially dissociated in impact melt rock from a Canadian impact crater.
- Former presence of cubic ZrO2 is crystallographically encoded in reaction rims.
- Cubic zirconia required >2370 °C melt, which is hottest recorded on Earth's surface.
- Such superheated melt susceptible to devolatilization resulting in dry rigid crust.
- Potential global effects for crustal evolution during bombardment of early Earth.