Between the land sloping away from the base of these rock layers and the layers themselves, there is a gap of nearly 3 billion (yes, billion with a "b") years of geologic history, also known as an unconformity.
Between the land sloping away from the base of these rock layers and the layers themselves, there is a gap of nearly 3 billion (yes, billion with a "b") years of geologic history, also known as an unconformity.