The Formation Of Devils Tower

Of the Great Plains in Wyoming, Devils Tower is an “upstanding” feature. It is located on the northwestern part of the Black Hills-Bear Lodge uplift, which is a mountainous region. During the Laramide Orogeny, about 60 million years ago, this region formed. The process of the formation of mountains is called an orogeny. Rocky Mountain ranges, such as the Bighorn Mountains and Uinta Mountains were formed by the Laramide Orogeny.
Devil Tower stands 867 feet from base to summit, and above sea level its elevation is 5,112 feet and around 1,267 feet above the north-flowing Belle Fourche River. Sedimentary, igneous, and erosional processes led to the formation of Devils Tower National Monument. First, sedimentary rocks in layers, which are nearly two miles thick, were deposited. About 500 million years ago, most of the layers were deposited in shallow seas. Igneous activity then created the tower until erosional processes exposed it.
The Black Hills region, which is an elliptical dome, was formed
Large crystals, that contained molten lava and change environments by moving into an area with lower temperatures, would cool quickly. A porphyritic texture is where large and small crystals are embedded; therefore, porphyry contains this texture. The matrix, around the large phenocrysts, is formed by the small crystals. Phonolite porphyry is the igneous rocks that form Devils Tower. In the Phonolite, the white phenocrysts are made up of feldspar. Smaller black phenocrysts may be made up of augite. These crystals were formed when the magma, that formed the tower and deep underground, cooled slowly. The magma, including phenocrysts, moved upward until about a mile below the surface, and then formed the rest of the crystals. The rest of the magma cooled quickly, at cooler temperatures, and formed the aphanitics. Aphanitics are gray rocks, with fine-grained texture, around the