Nadja Drabon on a New Lens into the Hadean Eon

Glossary

Acasta gneiss - coarse-grained igneous rock of felsic composition found in the Slave craton in northwestern Canada

compatible trace element - element that is stable within a mineral crystal structure, and thus less likely to enter a melt phase as the temperature rises and, conversely, quicker to enter newly formed mineral crystals upon cooling

felsic - of rocks such as granite, which are high in light-colored minerals, including feldspar and quartz

interferences (in detecting trace elements) - spectral line blending (with peak overlap in wavelength) of different elements

sagduction - where a block of crust falls off and simply sinks into the mantle

zircon - ultra-durable crystal of zirconium silicate common in many igneous and metamorphic rocks, typically 0.1–0.3 mm in size, found in the Earth crust