text: This rock forms the Coconino and Tapeats layers of the Grand Canyon.
full_question: This rock forms the Coconino and Tapeats layers of the Grand Canyon. Paleocurrents can be tracked by stratum at an angle in this rock, like that at the Canyons of the Escalante. This rock's "arkose" variety contains more than 25 percent feldspar. Compression-driven metamorphism of this rock in orogenic belts can form quartzite. For 10 points--name this sedimentary rock that forms out of a namesake granular material found on beaches.
first_sentence: This rock forms the Coconino and Tapeats layers of the Grand Canyon.