Earth’s Oldest-Known Rocks | 02 Jul 2025

Source: TH 

A volcanic rock belt in Quebec’s (Canada) Nuvvuagittuq Greenstone Belt, dated to be 4.16 billion years old, has been identified as the oldest-known rock on Earth, originating from the Hadean eon (4.5–4.03 billion years ago), when Earth itself was formed about 4.6 billion years ago. 

• The rocks are metamorphosed volcanic basalt, formed when magma solidified underground, and provide clues about Earth’s early crust, primordial oceans, and the environment where life may have begun. 
• Two radioactive dating methods (samarium-neodymium decay) confirmed the age, making them the oldest-known intact rocks. 
• Zircon crystals from Australia (4.4 billion years old) remain the oldest mineral fragments, but the Quebec rocks are the oldest intact geological formations. 
• The Hadean eon (4.5–4.03 billion years ago) was previously thought to be a molten hellscape (extremely harsh, hostile, or dangerous to life), but evidence suggests a cooling crust, shallow oceans, and an early atmosphere.