The Navajo Sandstone is a major rock formation of the Glen Canyon Group spread across parts of the American Southwest, especially Utah, where it helps shape the Colorado Plateau and the scenery of parks such as Zion, Arches, Canyonlands, Capitol Reef, Glen Canyon, and Grand Staircase–Escalante. Deposited in an arid Jurassic sand sea on western Pangaea, it is known for pale colors, large cross-bedding, smooth weathering, and vast cliffs and domes. Later groundwater altered iron in the rock, creating vivid colors, ironstone features, and Moqui Marbles. It also preserves dinosaur tracks and remains an important record of an immense ancient desert.