One Billion Years Missing: The Rock Layer Erased Before Life Exploded

In Arizona’s Grand Canyon, rock about 520 million years old rests directly on metamorphic basement more than 1.7 billion years old. There is no continuous set of layers between them. The gap is not a few thousand years or a human generation. At some points, nearly 1.2 billion years of geological history is absent from the rock.

In Arizona’s Grand Canyon, rock about 520 million years old rests directly on metamorphic basement more than 1.7 billion years old. There is no continuous set of layers between them. The gap is not a few thousand years or a human generation. At some points, nearly 1.2 billion years of geological history is absent from the rock.

In Arizona’s Grand Canyon, rock about 520 million years old rests directly on metamorphic basement more than 1.7 billion years old. There is no continuous set of layers between them. The gap is not a few thousand years or a human generation. At some points, nearly 1.2 billion years of geological history is absent from the rock.

In Arizona’s Grand Canyon, rock about 520 million years old rests directly on metamorphic basement more than 1.7 billion years old. There is no continuous set of layers between them. The gap is not a few thousand years or a human generation. At some points, nearly 1.2 billion years of geological history is absent from the rock.