Akilia

Akilia, a small island in southwestern Greenland south of Nuuk, is important for a controversial rock outcrop tied to debates over Earth’s earliest history. Its metamorphosed supracrustal rocks are dated to no younger than 3.85 billion years old, and iron- and silica-rich layers within them have been variously interpreted as banded iron formation, chemical sediments near submarine hot springs, or hydrothermal vein deposits. Graphite in the rocks has low carbon-13 levels that some have argued reflect organic matter from living organisms, but that claim is disputed. Because later high-grade metamorphism complicates the rocks’ origin, age, and carbon signature, Akilia remains central to questions about whether life existed on Earth that early.