Soil from the erosions bury the base of the mountains, forming a long, gentle slope called pediment . The pediment is more fertile than other regions and therefore contains more plant and animal life. Other landforms in the desert are hammadas and buttes . Hammadas are rocky, dome-shaped plateaus that contain almost no soil and no plant life. Streams and winds erode and wear down hammadas, and the remains of these hammadas stand out boldly in the desert.
Buttes are peaks of hard rocks left behind after land has been eroded.
These are often shaped as smaller pinnacles and towers . Mesas are steep wall formations with flat tops and are the remains of plateaus. Alluvial fans are usually formed by the handiwork of mountains, streams, and rivers which carry large quantities of soil and gravel, called alluvium, to deserts below. Mountain tops often experience rain or snow, which flows down the sides of the mountain, eroding the soil, and forming canyons and ravines in the mountains. At the base of the mountain, a fan shape is created by the spreading out of dirt and rocks.