19. Search for 36 06 05.56N 112 05 45.40W and spend some time exploring the park, especially here at the bottom of the canyon where the older rocks are exposed. Also take some time to explore the NPS website on the area. How old are the metamorphic rocks found within the park? a. ~4 billion years old b. ~3 billion years old c. ~2 billion years old d. ~540 million years ol