The oldest rocks and minerals on Earth
Much of the evidence from the oldest period of the Earth’s history, the Hadean era (3.8 to 4.5 billion years ago), has been destroyed by erosion, burial, and modifications of the rocks as they were heated and compressed at depth. Yet clues can be found in the durable mineral zircon. Zircon usually contains a small amount of the radioactive element uranium, and its age can be determined by measuring how much of the uranium has transformed to lead.
Topic: Earth Science
Subtopic: Minerals and Resources
Keywords: Earth (Planet)--History, Earth (Planet)--Origin, Geology, Minerals, Rocks, Zircon
By dating the zircons embedded within the Acasta gneiss, geologists have determined its age to be 3.96 billion years.
This quartz pebble conglomerate formed three billion years ago, but the zircon crystals in it are up to 4.276 billion years old, making them the oldest dated material on Earth.