This four-billion-year-old rock sample from the Acasta Gneiss Complex in the Northwest Territories was used to determine how the Earth's earliest continental crust formed. Disclaimer: AAAS and ...

More specifically, they studied zircons in the 3.9–2.7-billion-year-old Saglek-Hebron Complex and 4.0–3.4-billion-year-old Acasta Gneiss Complex and found that instead of a linear progression of ...

Marcia Bjornerud on Geopedia Geopedia is a trove of geologic wonders and the evocative terms that humans have devised to describe them. Featuring dozens of entries—from Acasta gneiss to Zircon—this ...