Front matter
Reading edition
THE GRAND CANYON—1. SCHISTS AND GRANITES (ARCHEAN ERA): 2. SANDSTONES, LIMESTONES, SHALES (ALGONKIAN ERA): 3. TONTO FORMATIONS (CAMBRIAN PERIOD): 4. REDWALL LIMESTONE (MISSISSIPPIAN PERIOD): 5. SUPAI SANDSTONE AND SHALE (PERMIAN PERIOD): 6. HERMIT SHALE (PERMIAN PERIOD): 7. COCONINO SANDSTONE (PERMIAN PERIOD): 8. TOROWEAP AND KAIBAB FORMATIONS (PERMIAN PERIOD). NATIONAL PARK SERVICE