Description
The Colorado River and its tributaries established a course through the Grand Canyon about five to six million years ago exposing nearly two billion years of Earth’s geological past by cutting channels through layer after layer of rock. Scientists studying this world premiere geologic landscape 150 years ago discovered a curious phenomenon revealed by a gap in the canyon’s geologic history: a billion years of rock layer is missing. Recently, scientists have used new analytical methods to decipher the history in the missing window of time and solve the mystery.
