Base your answers to questions 80 through 82 on the generalized cross section of the Grand Canyon

represented below and on your knowledge of Earth science. Some rock layers have been labeled. The rock layers

have not been overturned.


State the approximate age of the Redwall limestone, in million years. [1]

Base your answers to questions 80 through 82 on the generalized cross section of the Grand Canyon represented below and on your knowledge of Earth science. Some class=