where is the grand canyon located in az
Grand Canyon The canyon and adjacent rim are contained within Grand Canyon National Park, the Kaibab National Forest, Grand Canyon-Parashant National Monument, the Hualapai Indian Reservation, the Havasupai Indian Reservation and the Navajo Nation. President Theodore Roosevelt was a major proponent of preservation of the Grand Canyon area, and visited it on numerous occasions to hunt and enjoy the scenery.
Geology of the Grand Canyon area At about 2.5 and 1.8 billion years ago in Precambrian time, sand, mud, silt, and ash were laid down in a marine basin adjacent to an orogenic belt.[1] From 1.8 to 1.6 billion years ago at least two island arcs collided with the proto-North American continent.[2] This process of plate tectonics compressed and grafted the marine sediments in the basin onto the mainland and uplifted them out of the sea. Later, these rocks were buried 12 miles (19 km) under the surface and pressure-cooked into metamorphic rock.[3] The resulting Granite Gorge Metamorphic Suite, which is part of the Vishnu Basement Rocks, consists of the metasedimentary Vishnu Schist and the metavolcanic Brahma and Rama Schists that were formed 1.75 billion to 1.73 billion years ago.[4] This is the resistant rock now exposed at the bottom of the canyon in the Inner Gorge.