The Grand Canyon of the Colorado River is a world-renowned showplace of geology. Geologic studies in the park began with the work of Newberry in 1858, and continue today. The Grand Canyon’s excellent display of layered rock is invaluable in unraveling the region’s geologic history. Extensive carving of the plateaus allows for the detailed study of the Earth’s movements. Processes of stream erosion and vulcanism are also easily seen and studied.

The Colorado River has carved the Grand Canyon into four plateaus of the Colorado Plateau Province. The Province is a large area in the Southwest characterized by nearly-horizontal sedimentary rocks lifted 5,000 to 13,000 feet above sea level. The Plateau’s arid climate produced many striking erosional forms, culminating in the Grand Canyon. The Canyon’s mile-high walls display a largely undisturbed cross section of the Earth’s crust extending back some two billion years. Three “Granite Gorges” expose crystalline rocks formed during the early-to-middle Proterozoic Era (late Precambrian). Originally deposited as sediments and lava flows, these rocks were intensely metamorphosed about 1,750 million years ago. Magma rose into the rocks, cooling and crystallizing into granite, and welding the region to the North American continent….Read More