The dark, glossy streaks on the desert rock are varnish formed by manganese and iron. At the foot of the Wingate cliffs, the Chinle Formation includes sandstone and siltstone laid down by water, plus volcanic ash carried by wind; uranium was later mined from this layer. The Wingate cliffs themselves were built from ancient desert dunes and can reach 500 feet.
Look for the thinner bands in the Kayenta Formation, deposited by streams; erosion can expose dinosaur tracks in its ledges. Higher Navajo Sandstone preserves cross-bedding from old dunes, while vertical cracks called joints guide water, ice and roots as they break the rock apart.